@charset "UTF-8";@-webkit-keyframes transparent-to-yellow{0%,to{background:0 0}25%,75%{background:#ff9}}@keyframes transparent-to-yellow{0%,to{background:0 0}25%,75%{background:#ff9}}@-webkit-keyframes highlight{0%,60%{background-color:#ff9}to{background-color:#fff}}@keyframes highlight{0%,60%{background-color:#ff9}to{background-color:#fff}}@font-face{font-family:'Harding';src:url(/static/fonts/HardingText-Regular-Web.b167e675dc.woff2) format("woff2"),url(/static/fonts/HardingText-Regular-Web.62711b6c07.woff) format("woff");font-display:fallback}@font-face{font-family:'Harding';src:url(/static/fonts/HardingText-Bold-Web.72203f58c0.woff2) format("woff2"),url(/static/fonts/HardingText-Bold-Web.d102a21e4f.woff) format("woff");font-display:swap;font-weight:700}@font-face{font-family:'Harding';src:url(/static/fonts/HardingText-RegularItalic-Web.a3136343af.woff2) format("woff2"),url(/static/fonts/HardingText-RegularItalic-Web.3cd6cb26e4.woff) format("woff");font-display:swap;font-style:italic}@font-face{font-family:'Harding';src:url(/static/fonts/HardingText-BoldItalic-Web.fe6dc3019e.woff2) format("woff2"),url(/static/fonts/HardingText-BoldItalic-Web.6db8bc0375.woff) format("woff");font-display:swap;font-weight:700;font-style:italic}html{font-family:sans-serif;line-height:1.15;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%;height:100%;overflow-y:scroll;font-size:62.5%}article,aside,details,figcaption,figure,footer,header,main,menu,nav,section{display:block}h1{font-size:30px}hr{-webkit-box-sizing:content-box;box-sizing:content-box;height:0;overflow:visible}code,kbd,pre,samp{font-family:monospace,monospace;font-size:1em}a,sub,sup{vertical-align:baseline}a{background-color:transparent;-webkit-text-decoration-skip:objects;text-decoration:none;color:#069}a:active,a:hover{outline-width:0}abbr[title]{border-bottom:none;-webkit-text-decoration:underline dotted}b,strong{font-weight:bolder}dfn{font-style:italic}mark{background-color:#ff0;color:#000}small{font-size:80%}sub,sup{font-size:75%;line-height:0;position:relative}sub{bottom:-.25em}sup{top:-.5em}audio,canvas,video{display:inline-block}audio:not([controls]){display:none;height:0}img{border:0;max-width:100%;height:auto;vertical-align:middle}svg:not(:root){overflow:hidden}button,input,optgroup,select,textarea{font-family:sans-serif;font-size:100%;line-height:1.15}optgroup,select{margin:0}button,input{overflow:visible}button,select{text-transform:none}[type=reset],[type=submit],button,html [type=button]{-webkit-appearance:button}[type=button]::-moz-focus-inner,[type=reset]::-moz-focus-inner,[type=submit]::-moz-focus-inner,button::-moz-focus-inner{border-style:none;padding:0}[type=button]:-moz-focusring,[type=reset]:-moz-focusring,[type=submit]:-moz-focusring,button:-moz-focusring{outline:1px dotted ButtonText}[type=checkbox],[type=radio],legend{-webkit-box-sizing:border-box;box-sizing:border-box}legend{color:inherit;display:table;max-width:100%;white-space:normal}progress{display:inline-block;vertical-align:baseline}textarea{overflow:auto}[type=checkbox],[type=radio]{padding:0}[type=number]::-webkit-inner-spin-button,[type=number]::-webkit-outer-spin-button{height:auto}[type=search]{-webkit-appearance:textfield;outline-offset:-2px}[type=search]::-webkit-search-cancel-button,[type=search]::-webkit-search-decoration{-webkit-appearance:none}::-webkit-file-upload-button{-webkit-appearance:button;font:inherit}summary{display:list-item}[hidden],template{display:none}.c-article-box__controls button:focus,.c-article-box__controls button:hover,.c-pan-zoom-controls button:focus,.c-pan-zoom-controls button:hover,a:focus,a:hover{text-decoration:underline}button{cursor:pointer;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;border-radius:0}h2{font-size:24px}h3{font-size:17px}h4{font-size:14px}cite{font-style:normal}ins{text-decoration:none}b:focus,dd:focus,div:focus,dl:focus,dt:focus,em:focus,h1:focus,h2:focus,h3:focus,h4:focus,h5:focus,i:focus,li:focus,ol:focus,p:focus,span:focus,strong:focus,ul:focus{outline:0}input+label{padding-left:.5em}nav ol,nav ul{list-style:none;list-style-image:none}table{width:100%;margin-bottom:0;border-collapse:collapse;border-spacing:0;font-size:1.6rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}tbody tr:first-child{border-top:0}.c-article-header,body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}body{min-height:100%;line-height:1.76;color:#222;background:#eee}.c-article-header{margin-bottom:40px}.c-article-identifiers{list-style:none;font-size:1.6rem;line-height:1.3;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;color:#6f6f6f;padding:0;margin:0 0 8px}.c-article-identifiers__item{border-right:1px solid #6f6f6f;margin-right:8px;padding-right:8px;list-style:none}.c-article-identifiers__item a,.c-article-identifiers__item a:active,.c-article-identifiers__item a:hover,.c-article-identifiers__item a:visited{color:#069}.c-article-change-list__item>ins,.c-article-identifiers__item a,abbr[title]{text-decoration:none}.c-article-identifiers__item a:hover{text-decoration:underline}.c-article-identifiers__item:last-child{margin-right:0;padding-right:0;border-right:0}.c-article-identifiers__open{color:#b74616}@media only screen and (min-width:768px){.c-author-popup .c-article-identifiers{-webkit-box-pack:end;-webkit-justify-content:flex-end;-ms-flex-pack:end;justify-content:flex-end}}.c-article-title{font-size:2.4rem;line-height:1.25;margin-bottom:16px}@media only screen and (min-width:768px){.c-article-title{font-size:3rem;line-height:1.2}}.c-article-title__super{font-size:1.6rem;line-height:1.3;color:#626262;margin:16px 0 0}.c-author-list{font-size:1.6rem;list-style:none;margin-bottom:0;padding:0;width:100%}.c-author-list__item{margin-left:0}.c-author-list li,.c-author-list__item{display:inline;padding-right:0}.c-article-references__download svg,.c-author-list__item svg,.c-bibliographic-information__download-citation svg,.c-reading-companion__figure-full-link svg{margin-left:4px}.c-author-list__show-less{margin-left:8px}.c-author-list__show-more{margin-right:4px}.c-article-info-details{font-size:1.6rem;margin-bottom:8px;margin-top:16px}.c-article-info-details__cite-as,.c-article-info-details__show-history{border-left:1px solid #6f6f6f;margin-left:8px;padding-left:8px}.c-article-info-details+.c-article-info-details{margin-top:0}.c-article-metrics-bar{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;line-height:1.3;font-size:1.6rem}.c-article-metrics-bar__item{-webkit-box-align:baseline;-webkit-align-items:baseline;-ms-flex-align:baseline;align-items:baseline;border-right:1px solid #6f6f6f;margin-right:8px}.c-article-metrics-bar__item:last-child{border-right:0}.c-article-metrics-bar__count{font-weight:700;margin:0}.c-article-metrics-bar__label{color:#626262;font-weight:400;font-style:normal;margin:0 10px 0 5px}.c-article-metrics-bar__details{margin:0}.c-article-author-affiliation__list,.c-article-author-authors-search,.c-article-author-information__list,.c-article-author-institutional-author,.c-article-further-reading__list,.c-article-references,.c-article-supplementary__list{list-style:none;padding:0}.c-article-footnote--listed{list-style:none}.c-article-change-list,.c-article-references__nav{list-style:none;padding:0}.c-article-main-column{font-family:Harding,Palatino,serif;margin-right:8.6%;width:60.2%}@media only screen and (max-width:1023px){.c-article-main-column{margin-right:0;width:100%}}.c-author-popup__subheading{font-weight:700;float:left;padding-right:8px;margin-bottom:8px;margin-top:4px}.c-author-popup__footer-heading{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;font-size:1.6rem;font-weight:700;margin:0}.c-author-popup__author-list{list-style:none;font-size:1.6rem;padding:0;margin-top:0;clear:both;margin-bottom:16px}.c-author-popup__author-list>li{margin-bottom:8px}.c-author-popup__link{font-weight:700;vertical-align:baseline;color:#069;text-decoration:none}.c-author-popup .c-article-button{color:#fff;background:#069;border:1px solid #069;border-radius:2px;text-decoration:none;font-size:1.6rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;display:block;width:100%;padding-top:8px;padding-bottom:8px;text-align:center}.c-author-popup .c-article-button:visited{color:#fff}.c-author-popup .c-article-button:hover{color:#069;background:#fff;text-decoration:none}.c-article-aop{font-size:1.4rem;color:#626262;font-style:italic;margin-bottom:16px;padding-top:10px;clear:both}.c-article-section{clear:both}.c-article-section a{word-break:break-word}.c-article-section__title{border-bottom:2px solid #d5d5d5;font-size:2rem;line-height:1.3;padding-bottom:8px}@media only screen and (min-width:768px){.c-article-section__title{font-size:2.4rem;line-height:1.24}}.c-article-section__content{margin-bottom:40px}.c-article-section__content--standfirst{font-weight:700}.c-article__pill-button{padding:8px 20px;background-color:#fff;border:4px solid #bcd2dc;border-radius:20px;font-size:1.4rem;line-height:1.4;font-weight:700;-webkit-transition:background-color .2s ease-out,color .2s ease-out;transition:background-color .2s ease-out,color .2s ease-out;margin-bottom:10px;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;display:inline-block}.c-article__pill-button:hover{background-color:#069;color:#fff}.c-article-subject-list-item__link:focus,.c-article__pill-button:focus{outline:0;-webkit-box-shadow:0 0 0 3px #fece3e;box-shadow:0 0 0 3px #fece3e}.c-article-subject-list-item__link:active,.c-article-subject-list-item__link:hover,.c-article__pill-button:active,.c-article__pill-button:hover{-webkit-box-shadow:0 0 0 0;box-shadow:0 0 0 0}.c-article-section__illustration{clear:both;font-size:1.4rem}.c-article-section__illustration-right{margin:8px 0 16px 28px;float:right;padding:0}.c-article-section__illustration-center{margin:0 auto 24px;max-width:100%;padding:0}@media only screen and (min-width:1024px) and (max-width:767px){.c-article-section__illustration-center,.c-article-section__illustration-right{margin:0 auto 24px;float:none;max-width:100%}}@media only screen and (max-width:539px){.c-article-section__illustration-center,.c-article-section__illustration-right{margin:0 auto 24px;float:none;max-width:100%}}@media only screen and (max-width:1023px){.c-article-section__content{padding-left:0}}.c-article__sub-heading{font-weight:400;font-size:2rem;line-height:1.3;margin-bottom:8px}@media only screen and (min-width:768px){.c-article__sub-heading{font-size:2.4rem;line-height:1.24}}.c-article__sub-heading--small{font-size:16px;line-height:1.5}.c-article-author-institutional-author__author-list .c-article-author-institutional-author__author-list .c-article-author-institutional-author__sub-division,.c-article__sub-heading--light{color:#626262}.c-article__sub-heading--divider::before{content:'';display:block;width:30px;height:4px;margin-top:40px;margin-bottom:16px;background:#222}.c-article-access-provider,.c-notes{padding:8px 16px;border:1px solid #d5d5d5;border-left:none;border-right:none;margin:24px 0}.c-article-access-provider__text,.c-notes__text{padding-top:2px;padding-bottom:2px;margin-bottom:0;font-size:1.6rem;color:#555;text-align:center}.c-article-events{clear:both;font-size:1.6rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;list-style:none;margin-bottom:0;margin-top:16px;overflow:hidden;padding:0}.c-article-events+.c-article-events{margin-top:0}.c-article-events__item{background-color:#f0f7fa;margin-bottom:8px;padding:8px}.c-article-events__item--retraction{background-color:#fdf5f2}.c-article-peer-review{background-color:#f0f7fa;font-size:1.6rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;margin-top:-16px;margin-bottom:40px;padding:8px}.c-article-events__item>span,.c-article-peer-review>a{background:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'125%2025%2016%2016'%20enable-background%3D'new%20125%2025%2016%2016'%3E%3Cpath%20fill%3D'%23215F90'%20d%3D'M133%2025c-4.374%200-8%203.626-8%208s3.626%208%208%208%208-3.626%208-8-3.626-8-8-8zm1.173%2012.48c0%20.107%200%20.32-.32.32h-1.707c-.213%200-.32-.106-.32-.32v-5.76c0-.213.106-.32.32-.32h1.707c.213%200%20.32.213.32.32v5.76zM133%2030.333c-1.067%200-1.173-.534-1.173-1.067%200-.64.213-1.066%201.173-1.066s1.173.426%201.173%201.066c0%20.534-.106%201.067-1.173%201.067z'%2F%3E%3C%2Fsvg%3E") no-repeat 0 50%;padding-left:24px}.c-article-events__item--retraction>span{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'109.508%2034.751%2016%2016'%20enable-background%3D'new%20109.508%2034.751%2016%2016'%3E%3Cpath%20fill%3D'%23930721'%20d%3D'M125.382%2048.933l-7.35-12.914c-.314-.526-.734-.526-1.05%200l-7.35%2012.913c-.314.525%200%20.945.526.945h14.7c.524%200%20.84-.42.524-.945zm-8.61-9.555h1.47c.21%200%20.316.105.316.315l-.21%205.774c0%20.21-.105.315-.315.315h-1.05c-.21%200-.315-.105-.315-.315l-.21-5.774c0-.21.104-.315.315-.315zm.736%209.45c-1.05%200-1.155-.525-1.155-1.05%200-.63.21-1.05%201.155-1.05.945%200%201.155.42%201.155%201.05%200%20.525-.21%201.05-1.155%201.05z'%2F%3E%3C%2Fsvg%3E")}.c-article-change-list__item{margin-bottom:24px}.c-article-change-list__heading{color:#626262;display:inline;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;font-weight:700;margin-right:.5em}.c-article-change-list__details,.c-article-change-list__details>p:first-child{display:inline}.c-article-references__heading{font-weight:700;font-size:1.7rem;margin:24px 0 4px}.c-article-references__item{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;border-bottom:1px solid #d5d5d5;padding-bottom:16px;margin-bottom:16px}.c-article-references__item>h3,.c-article-references__item>p.c-article-references__text{-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1;padding-left:8px}.c-article-references__counter{font-size:2.4rem;line-height:1.4;text-align:right}@media only screen and (max-width:1023px){.c-article-references__counter{font-size:1.8rem;line-height:inherit}}.c-article-references__text{margin-bottom:8px}.c-article-references__links{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-basis:100%;-ms-flex-preferred-size:100%;flex-basis:100%;-webkit-box-pack:end;-webkit-justify-content:flex-end;-ms-flex-pack:end;justify-content:flex-end;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;font-size:1.6rem;font-weight:700;margin:0;padding:0;list-style:none}.c-article-references__links>a{padding-left:8px}.c-article-references__links>a:first-child{padding-left:0}.c-article-references__download{text-align:right}.c-article-references__download>a{font-size:1.6rem;font-weight:700;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.c-article-author-information__list{margin-top:0;margin-bottom:24px}.c-article-author-information__authors-list{padding:0;margin:0 0 8px;list-style:none;font-weight:700}.c-article-author-information__item{margin-bottom:16px}.c-article-author-information__subtitle{font-weight:700;margin:0 0 8px}.c-article-author-affiliation__address{color:inherit;font-weight:700;font-size:1.7rem;margin:0}.c-article-author-affiliation__authors-list{padding:0;list-style:none;margin-bottom:16px;margin-top:0}.c-article-author-affiliation__authors-item{display:inline;margin-left:0}.c-article-authors__list{padding:0;list-style:none}.c-article-authors-search,.c-article-authors__list{margin-top:0;margin-bottom:24px}.c-article-authors-search__item,.c-article-authors-search__title{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.c-article-authors-search__title{color:#626262;font-weight:700;margin:0;padding:0;font-size:1.7rem}.c-article-authors-search__item{font-size:1.6rem}.c-article-authors-search__text{margin:0}@media only screen and (min-width:768px){.c-author-popup .c-article-authors-search__list{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}.c-author-popup .c-article-authors-search__list-item--left{-webkit-flex-basis:40%;-ms-flex-preferred-size:40%;flex-basis:40%}}.c-article-footnote p+p,.c-author-popup .c-article-authors-search__list-item--right{margin-top:16px}@media only screen and (min-width:768px){.c-author-popup .c-article-authors-search__list-item--right{text-align:right;-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1;margin-top:0}}.c-article-author-institutional-author{margin-top:0;margin-bottom:24px}.c-article-author-institutional-author__name{font-weight:700;font-size:1.7rem;margin:0;padding:0}.c-article-author-institutional-author__author-list{padding:0;list-style:none;margin-top:0;margin-bottom:24px}.c-article-author-institutional-author__author-list--popup{clear:both;margin-bottom:16px}.c-article-author-institutional-author__author-name{display:inline;list-style:none}.c-article-author-institutional-author__sub-division{font-family:Harding,Palatino,serif;line-height:1.76;margin:0}.c-article-supplementary{margin-bottom:24px}.c-article-supplementary__item{margin-bottom:24px;position:relative}.c-article-supplementary__item>span{width:40px;line-height:1.4;font-weight:400;text-align:right;position:absolute;font-size:2.4rem}.c-article-supplementary__external{margin-bottom:16px}.c-article-supplementary__description{font-size:1.6rem}.c-article-supplementary__description>*{margin-bottom:0}.c-article-fullwidth-content{clear:both;font-family:Harding,Palatino,serif}.c-article-fullwidth-content__infographic{clear:both;position:relative;margin-bottom:24px;padding:0}.c-article-fullwidth-content__image{border:5px solid #dae5ea;position:relative}.c-article-fullwidth-content__image img{max-width:100%}.c-article-fullwidth-content__caption{margin:1px 0 20px}.c-article-fullwidth-content p{word-wrap:break-word}.c-article-supplementary--enumerated .c-article-supplementary__description,.c-article-supplementary--enumerated .c-article-supplementary__title{margin-left:50px}.c-article-data-availability-list{list-style:none;padding:0;overflow:hidden;margin:0 0 24px}.c-article-data-availability-list_item>*{margin-bottom:0}.c-article-data-availability-list_item>*+*{margin-top:24px}.c-article-further-reading__list,figure{margin:0}.c-article-further-reading__item{border-bottom:1px solid #d5d5d5;margin-bottom:16px;position:relative}.c-article-further-reading__item:last-child{border:0}.c-article-further-reading__title{font-size:1.7rem;font-weight:400;margin:0;padding:0}.c-article-further-reading__authors-list{padding:0;list-style:none;margin:8px 0 0;font-size:1.3rem;line-height:1.4;color:#626262}.c-article-compound-details__synonym-list>li,.c-article-further-reading__authors-list li{display:inline}.c-article-further-reading__journal-title{color:#626262;font-size:1.3rem;margin-bottom:24px;padding:0;word-wrap:break-word}.c-article-license{font-size:1.6rem;margin-bottom:24px}.c-article-license__link{float:left;margin-right:10px}.c-article-license__badge{margin-top:8px}.c-article-rights{font-size:1.6rem}.c-article-subject-list{font-size:1.6rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;list-style:none;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;padding:0;margin:0 0 24px}.c-article-subject-list__subject{background-color:#dae5ea;border-radius:20px;padding:4px 10px;font-weight:700;margin-right:15px;margin-bottom:16px;-webkit-box-flex:0;-webkit-flex:0 1 auto;-ms-flex:0 1 auto;flex:0 1 auto}.c-article-compound-title{margin:40px 0 16px;line-height:1.4}.c-article-compound-article-link{font-family:Harding,Palatino,serif}.c-article-compound-container{margin-bottom:16px}.c-article-compound-details{display:inline-block;margin-bottom:16px}.c-article-compound-details p{margin-bottom:16px;word-wrap:break-word}.c-article-compound-details__image{margin-bottom:16px;max-width:100%}.c-article-compound-details__links{color:#626262;font-size:1.4rem}.c-article-compound-details__synonym{margin-bottom:16px}.c-article-compound-details__synonym-list{padding:0;list-style:none}.c-bibliographic-information{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;padding-top:8px}@media only screen and (max-width:1023px){.c-bibliographic-information{padding-top:0;display:block}}.c-bibliographic-information__value{font-size:1.6rem;margin-bottom:16px;display:block}.c-bibliographic-information__column:first-child{width:81px;-webkit-box-flex:0;-webkit-flex:0 0 81px;-ms-flex:0 0 81px;flex:0 0 81px}@media only screen and (max-width:1023px){.c-bibliographic-information__column:first-child{width:100%}}.c-bibliographic-information__column:last-child{-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1}.c-bibliographic-information__column--border{border-right:1px solid #d5d5d5;margin-right:24px}@media only screen and (max-width:1023px){.c-bibliographic-information__column--border{border-bottom:1px solid #d5d5d5;padding-bottom:8px;margin-bottom:8px;border-right:0;margin-right:0}}.c-bibliographic-information__list{list-style:none;margin:0;padding:0;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:start;-webkit-justify-content:flex-start;-ms-flex-pack:start;justify-content:flex-start;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap}.c-bibliographic-information__list-item{-webkit-box-flex:0;-webkit-flex:0 0 33%;-ms-flex:0 0 33%;flex:0 0 33%;-webkit-box-sizing:border-box;box-sizing:border-box;padding-right:8px;font-size:1.6rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}@media only screen and (max-width:1023px){.c-bibliographic-information__list-item{-webkit-box-flex:0;-webkit-flex:0 0 100%;-ms-flex:0 0 100%;flex:0 0 100%}}.c-bibliographic-information__list-item h4{font-style:normal;font-size:1.6rem}.c-bibliographic-information__list-item:last-child{padding-right:0}.c-bibliographic-information__list-item--doi{-webkit-box-flex:0;-webkit-flex:0 0 100%;-ms-flex:0 0 100%;flex:0 0 100%}.c-bibliographic-information__citation,.c-bibliographic-information__download-citation{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;font-size:1.6rem;margin-bottom:8px}.c-bibliographic-information__download-citation{margin-bottom:24px}.c-code-block{padding:20px;margin:0 0 24px;border:1px solid #eee;font-family:monospace}.c-code-block__heading{font-family:Harding,Palatino,serif;font-weight:400;margin-bottom:16px}.c-code-block__line{word-wrap:break-word;white-space:pre-wrap;display:block}.c-stack{display:inline-table;vertical-align:top}.c-stack sub,.c-stack sup{display:table-row;line-height:1}.c-literal{font-family:monospace}.c-blockquote{border-left:5px solid #d5d5d5;padding-left:10px;margin-bottom:24px;clear:both;position:relative}.c-blockquote--right{float:right;margin:24px;width:39.8%}.c-blockquote:after,.c-blockquote:before{content:'';height:7px;border-left:5px solid #fff;position:absolute;margin-left:-5px;left:0}.c-blockquote:before{top:0}.c-blockquote:after{bottom:0}.c-blockquote__body{font-family:Harding,Palatino,serif;font-weight:700;font-style:italic}.c-abbreviation_list__description p,.c-blockquote__body>*{margin-bottom:0}.c-description-list{margin:0;padding:0}.c-description-list__term{font-weight:700}.c-description-list__description{padding-left:30px;margin:0}.c-abbreviation_list{margin:0;padding:0}.c-abbreviation_list__term{float:left;font-weight:700;margin-right:15px}.c-abbreviation_list__term dfn{font-style:initial}.c-abbreviation_list__description,.c-book-review{margin-bottom:24px}.c-book-review{margin-top:40px;padding:30px 0 20px 20px;border-bottom:2px solid;border-top:2px solid;-o-border-image:linear-gradient(to right,#fff,#fff 23%,#eee 0,#eee 74%,#fff 23%,#fff) 10;border-image:-webkit-gradient(linear,left top,right top,from(#fff),color-stop(23%,#fff),color-stop(0,#eee),color-stop(74%,#eee),color-stop(23%,#fff),to(#fff)) 10;border-image:linear-gradient(to right,#fff,#fff 23%,#eee 0,#eee 74%,#fff 23%,#fff) 10;font-size:1.3rem}.c-book-review__title{font-weight:700;font-size:1.7rem;line-height:1.3}.c-book-review__image{width:75px;margin-top:10px;min-height:75px;vertical-align:middle;padding-right:30px;-webkit-perspective:195px;perspective:195px;-webkit-perspective-origin:left;perspective-origin:left;-webkit-transform-style:preserve-3d;transform-style:preserve-3d;-webkit-backface-visibility:visible;backface-visibility:visible;float:left}.c-book-review__image:before{top:2%;height:96%}.c-book-review__image:after,.c-book-review__image:before{position:absolute;content:' ';z-index:-1}.c-book-review__image:before{width:75px;min-height:75px;left:6%;background-color:#eee;-webkit-transform:rotateY(-20deg) perspective(195px);transform:rotateY(-20deg) perspective(195px);-webkit-box-shadow:inset -2px 1px #8e8e8e;box-shadow:inset -2px 1px #8e8e8e}.c-book-review__image:after{top:14px;left:13px;width:88%;height:10%;-webkit-box-shadow:22px 80px 8px rgba(0,0,0,.3);box-shadow:22px 80px 8px rgba(0,0,0,.3);-webkit-transform:skew(-18deg) rotateZ(6deg);transform:skew(-18deg) rotateZ(6deg);-webkit-transform-origin:0 100%;transform-origin:0 100%}.c-book-review__image img{border:1px solid #9e9e9e;-webkit-transform:rotateY(-20deg) translateZ(1px) perspective(195px);transform:rotateY(-20deg) translateZ(1px) perspective(195px);-webkit-box-shadow:inset 4px 0 #9e9e9e;box-shadow:inset 4px 0 #9e9e9e}.c-book-review__list{padding:0;list-style:none;display:block;visibility:visible;margin-top:0;margin-bottom:10px}.c-book-review__list:last-child{margin-bottom:24px}.c-book-review__item{display:inline}.c-book-review__additional-info{margin-bottom:10px}.c-key-step{border:1px solid #069;margin-bottom:24px;padding:15px 15px 6px}.c-key-step--important{border-color:#b74616}.c-key-step__heading{background:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'125%2025%2016%2016'%20enable-background%3D'new%20125%2025%2016%2016'%3E%3Cpath%20fill%3D'%23215F90'%20d%3D'M133%2025c-4.374%200-8%203.626-8%208s3.626%208%208%208%208-3.626%208-8-3.626-8-8-8zm1.173%2012.48c0%20.107%200%20.32-.32.32h-1.707c-.213%200-.32-.106-.32-.32v-5.76c0-.213.106-.32.32-.32h1.707c.213%200%20.32.213.32.32v5.76zM133%2030.333c-1.067%200-1.173-.534-1.173-1.067%200-.64.213-1.066%201.173-1.066s1.173.426%201.173%201.066c0%20.534-.106%201.067-1.173%201.067z'%2F%3E%3C%2Fsvg%3E") no-repeat 0 50%;color:#069;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;font-weight:700;padding-left:20px;text-transform:uppercase}.c-key-step--important>.c-key-step__heading{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'109.508%2034.751%2016%2016'%20enable-background%3D'new%20109.508%2034.751%2016%2016'%3E%3Cpath%20fill%3D'%23AB5306'%20d%3D'M125.382%2048.933l-7.35-12.914c-.314-.526-.734-.526-1.05%200l-7.35%2012.913c-.314.525%200%20.945.526.945h14.7c.524%200%20.84-.42.524-.945zm-8.61-9.555h1.47c.21%200%20.316.105.316.315l-.21%205.774c0%20.21-.105.315-.315.315h-1.05c-.21%200-.315-.105-.315-.315l-.21-5.774c0-.21.104-.315.315-.315zm.736%209.45c-1.05%200-1.155-.525-1.155-1.05%200-.63.21-1.05%201.155-1.05.945%200%201.155.42%201.155%201.05%200%20.525-.21%201.05-1.155%201.05z'%2F%3E%3C%2Fsvg%3E");color:#b74616}.c-key-step__body{color:#626262;font-size:1.4rem;line-height:1.4;margin:0}.c-key-step__body>p{margin-bottom:16px}.c-key-step__body,.c-timing-step,.c-troubleshooting-step{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.c-troubleshooting-step{background:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'125%2025%2016%2016'%20enable-background%3D'new%20125%2025%2016%2016'%3E%3Cpath%20fill%3D'%23215F90'%20d%3D'M133%2025c-4.374%200-8%203.626-8%208s3.626%208%208%208%208-3.626%208-8-3.626-8-8-8zm1.173%2012.48c0%20.107%200%20.32-.32.32h-1.707c-.213%200-.32-.106-.32-.32v-5.76c0-.213.106-.32.32-.32h1.707c.213%200%20.32.213.32.32v5.76zM133%2030.333c-1.067%200-1.173-.534-1.173-1.067%200-.64.213-1.066%201.173-1.066s1.173.426%201.173%201.066c0%20.534-.106%201.067-1.173%201.067z'%2F%3E%3C%2Fsvg%3E") no-repeat 0 50%;font-weight:700;padding-left:20px;text-transform:uppercase;font-size:1.4rem}.c-timing-step{color:#626262;font-size:1.3rem;margin:0 0 8px}.c-article-box{border:5px solid #dae5ea;margin:0 0 24px;padding:0}.c-article-box__container{margin:0;overflow:hidden;padding:20px 20px 30px}.c-article-box__container-title{margin-bottom:8px;font-weight:700}.c-article-box__content>*,.c-article-footnote p{margin-bottom:0}.c-article-box__content>*+*{margin-top:24px}.c-article-box__controls{position:relative;margin-top:-56px}.c-article-box__controls button{display:block;font-weight:700;font-size:1.4rem;background-color:#dae5ea;color:#069;border:0;padding:10px 20px 6px;width:100%;cursor:pointer}.c-article-box__button-text:after{content:'';width:20px;height:10px;background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'7'%20viewBox%3D'0%200%2012%207'%3E%3Cpath%20fill%3D'%23006699'%20d%3D'M9.6%200l-3.6%204.3-3.6-4.3h-2.4l6%207%206-7h-2.4z'%2F%3E%3C%2Fsvg%3E");background-repeat:no-repeat;background-position:50% 50%;display:inline-block}.c-article-box--expanded .c-article-box__button-text:after{-webkit-transform:rotate(180deg);transform:rotate(180deg)}.c-article-box__fade{height:56px;background:-webkit-gradient(linear,left top,left bottom,from(rgba(255,255,255,0)),color-stop(25%,rgba(255,255,255,.38)),color-stop(50%,rgba(255,255,255,.75)),color-stop(75%,rgba(255,255,255,.85)),to(#fff));background:linear-gradient(to bottom,rgba(255,255,255,0) 0%,rgba(255,255,255,.38) 25%,rgba(255,255,255,.75) 50%,rgba(255,255,255,.85) 75%,#fff 100%)}.c-article-box--expanded .c-article-box__controls{margin-top:0}.c-article-box--expanded .c-article-box__fade{display:none}.c-warning{font-size:1.4rem;margin-bottom:20px;padding:8px 10px}.c-warning__link{color:#069;vertical-align:baseline}.c-warning--informative{background-color:#f0f7fa}.c-warning--informative .c-warning__icon{background:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'125%2025%2016%2016'%20enable-background%3D'new%20125%2025%2016%2016'%3E%3Cpath%20fill%3D'%23215F90'%20d%3D'M133%2025c-4.374%200-8%203.626-8%208s3.626%208%208%208%208-3.626%208-8-3.626-8-8-8zm1.173%2012.48c0%20.107%200%20.32-.32.32h-1.707c-.213%200-.32-.106-.32-.32v-5.76c0-.213.106-.32.32-.32h1.707c.213%200%20.32.213.32.32v5.76zM133%2030.333c-1.067%200-1.173-.534-1.173-1.067%200-.64.213-1.066%201.173-1.066s1.173.426%201.173%201.066c0%20.534-.106%201.067-1.173%201.067z'%2F%3E%3C%2Fsvg%3E") no-repeat 0 50%;padding-left:20px}.c-article-footnote{border-bottom:1px solid #d5d5d5;border-top:1px solid #d5d5d5;margin-bottom:24px;padding:20px 30px}.c-article-footnote--listed{border:0;padding:0}.c-article-footnote--listed__item{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;padding-bottom:16px;margin-bottom:16px}.c-article-footnote--listed__content{-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1;padding-left:12px;word-break:break-word}.c-article-footnote--listed__index{font-size:2.4rem;line-height:1.4;text-align:right}.c-article-share-box{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.c-article-share-box__title{font-weight:700;margin-bottom:8px}.c-article-share-box__description{font-size:1.6rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;margin-bottom:8px}.c-article-share-box__no-sharelink-info{font-size:1.3rem;font-weight:700;padding-top:4px;margin-bottom:24px}.c-article-share-box__only-read-input{border:1px solid #d5d5d5;display:inline-block;margin-bottom:8px;font-size:1.4rem;font-weight:700;padding:8px 10px}.c-article-share-box__only-read-input--highlighted{-webkit-animation:'transparent-to-yellow' 1.5s ease;animation:'transparent-to-yellow' 1.5s ease}.c-article-share-box__additional-info{color:#626262;font-size:1.3rem;margin-bottom:24px}.c-article-share-box__button{background:#fff;border:1px solid #069;-webkit-box-sizing:content-box;box-sizing:content-box;color:#069;font-size:1.6rem;line-height:1.5;margin-bottom:8px;padding:8px 20px;text-align:center}.c-article-share-box__button--link-like{background-color:transparent;border:0;color:#069;cursor:pointer;font-size:1.4rem;margin-bottom:8px;margin-left:10px}.c-article-correspondence__title{line-height:1.4;margin-bottom:16px}.c-article-correspondence__article{margin-bottom:24px}.c-article-correspondence__back-to-article{margin-bottom:16px}.c-article-correspondence__back-to-article--link{font-weight:700}.c-article-correspondence__alert{background-color:#959595;border:1px solid #626262;margin-bottom:20px;padding:20px}.c-article-correspondence__alert--error{background-color:#fcecec;border-color:#930721}.c-article-correspondence-form{margin-right:3.2%;width:100%}.c-article-correspondence-form__fieldset{width:100%;border:0}.c-article-correspondence-form__container{margin-bottom:40px}.c-article-correspondence-form__container--small{float:left;margin-right:3.2%;width:48.4%}@media only screen and (max-width:767px){.c-article-correspondence-form__container--small{width:100%}}.c-article-correspondence-form__container--last{margin-right:0}.c-article-correspondence-form__container--clear{clear:both}.c-article-correspondence-form__container--narrow{margin-bottom:20px}.c-article-correspondence-form__container--center{text-align:center}.c-article-correspondence-form__label,.c-article-metrics__altmetric-key>span{font-weight:700}.c-article-correspondence-form__label--required{border-bottom:none;color:#b12206;padding-right:4px;text-decoration:none}.c-article-correspondence-form__input{border:1px solid #959595;color:#222;padding:10px;line-height:1.25;-webkit-box-sizing:border-box;box-sizing:border-box;-webkit-transition:background-color .3s ease-in;transition:background-color .3s ease-in;width:100%}.c-article-correspondence-form__input--textarea{height:200px}.c-article-correspondence-form__submit{border:1px solid #069;background:#069;-webkit-box-sizing:content-box;box-sizing:content-box;color:#fff;display:block;line-height:1.5;min-width:auto;padding:8px 20px;text-align:center;-webkit-transition:background-color .2s ease-out,color .2s ease-out;transition:background-color .2s ease-out,color .2s ease-out;width:auto}.c-pan-zoom-controls{text-align:center;background:#dae5ea;border-bottom:6px solid #dae5ea;padding:8px 10px}.c-pan-zoom-controls ul{list-style:none;display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;margin:0;padding:0}.c-pan-zoom-controls li{border-left:1px solid #fff;padding:4px}.c-pan-zoom-controls li:first-child{border-left:none}.c-pan-zoom-controls button{border:0;padding:0 10px;background-color:transparent;color:#069}.c-pan-zoom-controls__zoom-in button,.c-pan-zoom-controls__zoom-out button{background-repeat:no-repeat;background-position:50% 50%;background-size:16px auto;width:16px;height:16px;padding:4px 20px}.c-pan-zoom-controls__zoom-in button{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'0%200%2016%2016'%3E%3Cpath%20fill%3D'%23006699'%20d%3D'M6%200h4v16h-4v-16zm-6%206h16v4h-16v-4z'%2F%3E%3C%2Fsvg%3E")}.c-pan-zoom-controls__zoom-out button{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'0%200%2016%2016'%3E%3Cpath%20fill%3D'%23006699'%20d%3D'M0%206h16v4h-16v-4z'%2F%3E%3C%2Fsvg%3E")}.c-article-equation{margin-bottom:24px;position:relative;width:100%;display:table;table-layout:fixed}.c-article-equation .MathJax_Display>.MathJax,.c-article-equation__content>.MathJax{display:block!important;max-width:100%;overflow-x:auto;overflow-y:hidden}.c-article-equation #MathJax_Zoom{background-color:#f7fbfe;border:1px solid #97bfd8;border-radius:2px;-webkit-box-shadow:0 0 5px 2px rgba(51,51,51,.2);box-shadow:0 0 5px 2px rgba(51,51,51,.2)}.c-article-equation__content{display:block;text-align:left;vertical-align:middle}@media only screen and (min-width:768px){.c-article-equation__content{display:table-cell;width:90%}}.c-article-equation__number{display:block;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;text-align:left;vertical-align:middle;margin:12px 0 16px}@media only screen and (min-width:768px){.c-article-equation__number{display:table-cell;width:10%;white-space:nowrap;text-align:right;padding-left:16px}}.c-article-equation__number{font-family:Harding,Palatino,serif;min-width:35px}.c-article-body{clear:both}.c-article-body a,.c-article-body p{word-wrap:break-word}.c-article-body a{word-break:break-word}.c-article-orcid__text{font-size:1.6rem;vertical-align:middle}.c-article-orcid:before{display:inline-block;width:24px;height:24px;content:url("data:image/svg+xml;charset=utf-8,%3Csvg height='24' viewBox='0 0 24 24' width='24' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cpath d='m0 0h24v24h-24z' fill='%23fff' opacity='0'/%3E%3Cpath d='m12 20c-4.418278 0-8-3.581722-8-8s3.581722-8 8-8 8 3.581722 8 8-3.581722 8-8 8zm-3.01799709-13.09169471c-.16628978-.16109322-.36635416-.24163862-.60019916-.24163862-.21825533 0-.410525.08444276-.57681478.25333081-.16628977.16888806-.24943341.36245684-.24943341.58071218 0 .22345188.08314364.41961891.24943341.58850696.16628978.16888806.35855945.25333082.57681478.25333082.233845 0 .43390938-.08314364.60019916-.24943342.16628978-.16628977.24943342-.36375592.24943342-.59240436 0-.233845-.08314364-.43131115-.24943342-.59240437zm-1.30173065 2.36492841v7.1712107h1.41865256v-7.1712107zm5.97732434.02508949h-2.9924703v7.14612121h2.9106249c.7673039 0 1.4476365-.1483432 2.0410182-.445034s1.0511995-.7152915 1.3734671-1.2558144c.3222677-.540523.4833991-1.1603247.4833991-1.8594238 0-.6854582-.1602789-1.3027023-.4808414-1.8517509-.3205625-.5490485-.7707074-.9753221-1.3504481-1.2788334-.5797408-.30351132-1.2413173-.45526471-1.9847495-.45526471zm-.1432294 6.06678581h-1.4681008v-4.9874504h1.4220628c.7877654 0 1.4143875.2233674 1.8798852.6701087.4654977.4467414.698243 1.05546.698243 1.8261742 0 .7434322-.2310402 1.3444779-.6931277 1.8031551-.4620874.4586773-1.0750688.6880124-1.8389625.6880124z' fill='%23999'/%3E%3C/g%3E%3C/svg%3E");margin-left:-3px;padding-right:4px;vertical-align:middle}.c-pdf-download{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;margin-bottom:24px;max-height:48px}@media only screen and (min-width:540px){.c-pdf-download{max-height:none}}@media only screen and (min-width:1024px){.c-pdf-download{max-height:48px}}.c-article-associated-content__container{clear:both;float:left;margin-bottom:16px;width:100%}.c-article-editorial-summary__container{border-bottom:1px solid #d5d5d5;margin-bottom:16px}.c-article-associated-content__title,.c-article-editorial-summary__title{line-height:1.4;margin-bottom:16px}.c-article-editorial-summary__article-title{font-size:1.4rem;line-height:1.4;margin-bottom:8px}.c-article-editorial-summary__content{font-family:Harding,Palatino,serif;font-size:1.4rem}.c-article-editorial-summary__content p:last-child{margin-bottom:0}.c-article-editorial-summary__content--less{max-height:9.5rem;overflow:hidden}.c-article-editorial-summary__button{background-color:#fff;border:0;color:#069;font-size:1.4rem;margin-bottom:16px}.c-article-editorial-summary__button:focus,.c-article-editorial-summary__button:hover{text-decoration:underline}.c-article-associated-content__collection,.c-article-associated-content__item{margin-bottom:24px;overflow:hidden}.c-article-associated-content__collection-label{color:#6f6f6f;font-size:1.3rem;line-height:1.4;margin-bottom:8px}.c-article-associated-content__collection-title,.c-nature-box{line-height:1.3;margin-bottom:8px}#uptodate-client{display:none!important}.c-nature-box{background-color:#fff;border-radius:2px;-webkit-box-shadow:0 0 5px 0 rgba(51,51,51,.1);box-shadow:0 0 5px 0 rgba(51,51,51,.1);border:1px solid #d5d5d5;padding:16px 16px 3px;margin-bottom:24px}.c-nature-box__text{margin-bottom:16px;font-size:1.6rem}.c-nature-box .c-pdf-download{margin-bottom:16px}.c-nature-box svg+.c-article__button-text{margin-left:8px}.c-nature-box--version{background-color:#eee}.c-nature-box__wrapper{-webkit-transform:translateZ(0);transform:translateZ(0)}.c-nature-box__wrapper--placeholder{min-height:165px}@media only screen and (min-width:1024px){.c-nature-box-mobile,.c-pdf-button__container{display:none}}.c-context-bar{position:relative;width:100%;-webkit-box-shadow:0 0 10px 0 rgba(51,51,51,.2);box-shadow:0 0 10px 0 rgba(51,51,51,.2)}@media only screen and (max-width:320px){.c-context-bar{width:auto}}.c-context-bar--sticky{position:fixed;z-index:10000;top:0;left:0}@media only screen and (max-width:320px){.c-context-bar--sticky{left:auto;right:0}}.c-context-bar--sticky:after{background-color:#fff;display:block;position:absolute;width:100%;height:100%;top:0;left:0;content:'';z-index:-1}@media only screen and (max-width:320px){.c-context-bar--sticky:after{background-color:#fff;-webkit-box-shadow:none;box-shadow:none}}.c-context-bar--no-button.c-context-bar--sticky,.c-context-bar__title{display:none}@media only screen and (min-width:540px){.c-context-bar--no-button.c-context-bar--sticky{display:block}}.c-context-bar--sticky .c-context-bar__container{padding:16px}@media only screen and (min-width:540px){.c-context-bar--sticky .c-context-bar__container{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;margin:0 auto;min-height:40px}}@media only screen and (max-width:320px){.c-context-bar--sticky .c-context-bar__container{padding:0}}.c-context-bar--sticky .c-context-bar__title,.c-context-bar--sticky .c-context-bar__title p{display:none}@media only screen and (min-width:540px){.c-context-bar--sticky .c-context-bar__title,.c-context-bar--sticky .c-context-bar__title p{display:block;-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1;padding-right:16px;overflow:hidden;white-space:nowrap;text-overflow:ellipsis}}.c-context-bar--sticky .c-context-bar__title p{margin-bottom:0}.c-article-main-column .c-context-bar--sticky .c-pdf-download{margin-bottom:0;display:block;white-space:nowrap}@media only screen and (min-width:540px){.c-context-bar--sticky .c-pdf-download__link{-webkit-box-flex:1;-webkit-flex:1 1 183px;-ms-flex:1 1 183px;flex:1 1 183px;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}.c-context-bar--sticky .c-pdf-download__link span{padding-right:16px}}@media only screen and (max-width:320px){.c-context-bar--sticky .c-pdf-download__link{padding:16px}.c-context-bar--sticky .c-pdf-download__link span{display:none}}.c-article-extras{float:left;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;width:31.2%}@media only screen and (max-width:1023px){.c-article-extras{display:none}}.c-pdf-download__link{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;color:#fff;background:#069;border:1px solid #069;border-radius:2px;text-decoration:none;font-size:1.6rem;line-height:1.3;-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1;padding:13px 24px}.c-pdf-download__link:visited{color:#fff}.c-pdf-download__link:hover{color:#069;background:#fff;text-decoration:none}.c-reading-companion{clear:both}.c-reading-companion__heading{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;font-size:1.6rem;font-weight:700;padding:0 16px 8px;margin:0}.c-reading-companion__sticky{max-width:582px}.c-reading-companion__sticky--stuck{margin:0 0 16px;position:fixed;top:50px}.c-reading-companion__scroll-pane{overflow-x:hidden;overflow-y:auto;margin:0 0 16px;max-height:calc(100vh - 100px)}.c-reading-companion__tabs{font-size:1.6rem;list-style:none;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-orient:horizontal;-webkit-box-direction:normal;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;-webkit-flex-wrap:nowrap;-ms-flex-wrap:nowrap;flex-wrap:nowrap;margin:0 0 8px;padding:0}.c-reading-companion__tabs>li{-webkit-box-flex:1;-webkit-flex-grow:1;-ms-flex-positive:1;flex-grow:1}.c-reading-companion__tab{color:#069;border:solid #d5d5d5;border-width:1px 1px 1px 0;background-color:#eee;padding:8px 8px 8px 15px;text-align:left;font-size:1.6rem;width:100%}.c-reading-companion__tab:focus{text-decoration:none;outline-offset:-4px}.c-reading-companion__tabs li:first-child .c-reading-companion__tab{border-left-width:1px}.c-reading-companion__tab--active{color:#222;background-color:#fff;border-bottom:1px solid #fff;font-weight:700}.c-reading-companion--highlighted{-webkit-animation:highlight 2s ease;animation:highlight 2s ease}.c-reading-companion__figures-list,.c-reading-companion__references-list,.c-reading-companion__sections-list{list-style:none;padding:0}.c-reading-companion__references-list--numeric{list-style:decimal;padding:0 0 0 30px}.c-reading-companion__sections-list{margin:0 0 8px;min-height:50px}.c-reading-companion__section-item{font-size:1.6rem;padding:0}.c-reading-companion__section-item a{display:block;padding:8px 0 8px 16px;line-height:1em;overflow:hidden;white-space:nowrap;text-overflow:ellipsis;text-decoration:none}.c-reading-companion__section-item a:hover{text-decoration:underline}.c-reading-companion__section-item--active a{white-space:normal;border-left:4px solid #d5d5d5;padding-left:12px;cursor:default;color:#222}.c-reading-companion__section-item--active a:focus,.c-reading-companion__section-item--active a:hover{outline:0;text-decoration:none}.c-reading-companion__figure-item{padding:16px 8px 16px 0;border-top:1px solid #d5d5d5;font-size:1.6rem}.c-reading-companion__figure-item:first-child{border-top:none;padding-top:8px}.c-reading-companion__reference-item{padding:8px 8px 8px 0;border-top:1px solid #d5d5d5;font-size:1.6rem}.c-reading-companion__reference-item:first-child{border-top:none}.c-reading-companion__reference-citation{margin:0;font-family:Harding,Palatino,serif}.c-reading-companion__reference-links{list-style:none;text-align:right;margin:8px 0 0;padding:0;font-weight:700;font-size:1.3rem}.c-reading-companion__reference-links>a{display:inline-block;padding-left:8px}.c-reading-companion__reference-links>a:first-child{display:inline-block;padding-left:0}.c-reading-companion__figure-title{font-weight:700;font-family:Harding,Palatino,serif;display:block;margin:0 0 8px}.c-reading-companion__figure-links{margin:8px 0 0;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between}.c-reading-companion__figure-links>a{display:inline-block}.c-reading-companion__figure-item picture:last-child{margin-bottom:16px}.c-reading-companion__panel{display:none;border-top:1px solid #d5d5d5;margin-top:-9px;padding-top:9px}.c-reading-companion__panel--active{display:block}.c-reading-companion__return{position:absolute;overflow:hidden;width:1px;height:1px}.c-reading-companion__return:focus{position:static;width:auto;height:auto;padding:0 4px}.c-article-section__figure{border:5px solid #d5d5d5;padding:20px 10px;max-width:100%;margin-bottom:24px;clear:both}.c-article-section__figure--1-border{border-width:1px;display:inline-block;position:relative;padding:0;margin:0}.c-article-section__figure--1-border-image{float:left;max-width:100%}.c-article-section__figure--no-border{border:0;padding:20px 0}.c-article-section__figure-caption{margin-bottom:8px;display:block}.c-article-section__figure-1-border-caption{border-bottom:1px solid #d5d5d5;color:#626262;font-size:1.3rem;margin:0;padding:8px 0;max-width:100%}.c-article-section__figure-credit,.c-article-table-container table{font-size:1.3rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;margin-bottom:16px}.c-article-section__figure-credit-right{text-align:right}.c-article-section__figure-content{margin-bottom:16px}.c-article-section__figure-item,.c-article-section__figure-link{display:inline-block;max-width:100%}.c-article-section__figure-link{margin:0 0 16px;padding:0}.c-article-section__figure-description{font-size:1.6rem}.c-article-section__figure-description>*{margin-bottom:0}.c-article-figure-title{line-height:1.4;margin:20px 0 16px}.c-article-figure-subtitle{font-size:1.8rem;font-family:Harding,Palatino,serif}.c-article-figure-content{clear:both}.c-article-figure-content-image{margin-bottom:16px;text-align:center}.c-article-figure-content-image:after,.c-article-figure-content-image:before{content:' ';display:table}.c-article-figure-content-image:after{clear:both}.c-article-figure-content-image-inline{display:inline-block}.c-article-figure-description{font-family:Harding,Palatino,serif;margin:0 0 24px}.c-article-figure-description>*{margin-bottom:0}.c-article-figure-description>*+*{margin-top:24px}.c-article-figure-button-container,.c-article-metrics__button-container{text-align:right}.c-article-table{border:5px solid #d5d5d5;clear:both;padding:20px 10px;margin-bottom:24px}.c-article-table-image{text-align:center}.c-article-table-title,.c-article-table__figcaption{margin-bottom:16px;line-height:1.4}.c-article-table__figcaption>b{padding-left:160px;min-height:90px;background:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAJYAAABQCAAAAADe29OXAAAGeUlEQVQYGc3BwY7kynmE0S/+TLJ75koGbEPwyu//agZkDGzgama6yIxwdWnFAjvpZZ2jH79x2RwV/2Tmin8y57pDFXEAFTtzoTfrj792oJqKI0siSWcugIDiXGGVEgqE6MzVIHd0W8E8ETFCZq4ghohzDgn2CiROY67vTuT03nDcOOo2ULUzZ6ESDM4VIhQWkoowN6hSW9Vve5PCkw9VkT2NCyHciXO7FKu3mxMoibmP3ry1Ze1Nicb/8mR9X9l+37jwt+x3w+KchNPW9X3fbnuQmas/uqi1dyPiHzz5/t39zx9DzP1t1M8fY9D5ikZ5/c+x7/+FVWFuedvagt15+MaR14bammIuqK1YxTmjUV4W9awKjQsWRFLnoXHUuxx1hbmg1oXMuYZajVaoLRXKzFVTCHQewlHFd1GYEyRB4ZxAIgOHu4S5KhGhzkPjKDykcS1A45xDwKPyoMacxEPnITxRqZUULqmEwjmh6FMhgcKF8NB5MEcNBQnz/xGZcy0BqRQQ1GBO4aHzII4Sf5K4EjuMxrk8kNhJJDGXgCBVxOo86142LeJCWtqq9s4XIlpGc9X+Fmlwoe9oyHRA0r9zlKZR39YUc0JvzSq+4DbSrGVolRspLixl4r0HUL3zxKaa07gQ+kJSnBs9o2rsVG9SUswFR623zqeEo0IEMHOCADLn4sQJCgQwcwEE1QWxzZGq4kRhrgqPVBt8YZT2LMtwDFSYS3Xt2+YuPn1wNNa3xm1zMfeN7LdRLZyTq/Yk3cNjpIq5RgRUDyC9cRSRWms05gp6C19LT1VtXYuyR2KuD6Pq9ICk/+Co//xzW76/tTD337S39wWHc1YbXvb/GVq/d6jB3P7rFnCKVLzyZC9EmrlQieQRvlBtqEWpQWNkcKE7jRTFSypeUvGSipdUvKTiJRUvqVJRD09qgGoUF2SriPhCpXq0FJUBLi6oF8quzl0kjmxE4uKCIHfinI3ijJIEiZizXVKji7vwpEqAiisqKBTOqUIpCkIVhQvCKtG5C+ZoLcVR27ggCUkb54qgRLtsA2ZOUoLTgYTi6Pce4Zs7F8RegoVzERCWUhfBxdwW7pSOIPydo+6U9p2duabcdpLBF2r0jPpouv2Sg5h7241U1fkUcbRHwk4xF2In7pxTp+JeBUEkzN0iAnQgoThqdlAjzAVEIXFul/FetRGQEHOWEjs9qZI/OFJrjJGIuda0b64WvrBRDL4pGRaIuX1ZFaPOJ31wpEWted+58Bec2MOcqyCSLEnsRMytslRF55P+jSPH1vpGMfeB3t4DxTlDKDbUVwiduWGQQhdJ8VeO2q+fe3t774O5j7S3txLmC9JgGX9+1PK2IA3mtttmYhd3Kp6MQIlwoYhKCV9JCP4AtSLhwloBQudOVRyNIO6KuRqBWMU5u2THxIndijnbiKouAgpHy66YWm5ckmg1ONe3VqrWt0QV9cFcHEHofBJP9iDswQUJj9D4gncxMtwikYQLuotNxcUIT9Rs1HYuGKHe+ErecauGjJwyF2SK6ileUvGSipdUvKTiJRUvqXhJ+vFLbhZHgQgpzBmJiQGU4gqfJOZsdfTHXzoP5ihSJeGKUBLEF1oihUbhKBZzJcUa6TwUR5ESJC5EIlKFczVQXG1rhMJiziW7KZ2HG0fuXRqOmFvIGJb4gvY0XFje0hiNOfeOqlXn4cbRvqor296YW5Kxj1CcqwEkW4/HGIzGXE9Ugs7Dv3CUZGhZxYVdWt8gxbkEFRmiViTChUHZg87Dv3Kk3z+3ev+2DOb+TlvfOi7O7YWrbr821u/damZu+8cWbDoP4Umo1nCYK1SlWJxrPXu13Ait7Y6YW3+6iChb8cqTNI8xanBljJA0vuJdGYsqMLSIC07J1VK8pOIlFS+peEnFSypeUvGSOrgWi6Ps3O2dC45jkDinrWlfE8p7jxczZ0HH6ghCOGqtpd3tzDW1agXmXFVRUota64rCnIqE0MVdeDKMsAdXREYQXxgjGjW4i22uBCWCzl3ym6Nsu6MUFwa5uUJxLqPw5k1sv8spMSdzJzqQ5B8cySH7wMxF2YYSvlARUdwzPggyc30gSnQEMU+CBCbMlbCFxTlHRKlKBqAwtyE+dR4aR0aAKOZSJEKNc0Og0EB8asztEhZ07pLBUREiaXBBJEiDc+Eu0pAQZDAnYSv03vaoh2dCkOJCKIjEXONBYm4I9aVZDohXkYKk+D9C+wq6RPTtKAAAAABJRU5ErkJggg==) no-repeat;display:block}@media only screen and (max-width:539px){.c-article-table__figcaption>b{background:0 0;padding-left:0;min-height:0}}.c-article-table-title{margin-top:20px}.c-article-table-subtitle{font-size:1.8rem;font-family:Harding,Palatino,serif}.c-article-table__inline-caption{font-weight:400;font-size:1.7rem;margin-bottom:16px}.c-article-table-container{font-family:Harding,Palatino,serif;margin-bottom:24px}.c-article-table-border{border:1px solid #d5d5d5}.c-article-table-container table{border:2px solid #d5d5d5;border-collapse:collapse;border-spacing:0;font-size:1.6rem;margin-bottom:0;width:100%}.c-article-table-container td,.c-article-table-container th{padding:6px;border-right:1px solid #d5d5d5;line-height:1.15}.c-article-table-head{border-bottom:5px solid #959595}.c-article-table-footer{padding:10px}.c-article-table-footer ol{list-style:none;margin:0;padding:0}.c-table-scroll-wrapper{position:relative}.c-table-scroll-wrapper__content{overflow-x:auto;min-width:100%}.c-table-scroll-wrapper__fade::after{content:'';width:30px;background-image:-webkit-gradient(linear,left top,right top,from(rgba(255,255,255,0)),color-stop(rgba(255,255,255,.6)),to(#fff));background-image:linear-gradient(to right,rgba(255,255,255,0),rgba(255,255,255,.6),#fff);position:absolute;right:0;top:0;bottom:0;opacity:1;-webkit-transition:opacity .25s ease-in-out;transition:opacity .25s ease-in-out;will-change:opacity}.c-table-scroll-wrapper__fade--transparent::after{opacity:0}.c-article-metrics__heading{line-height:1.4;margin-bottom:16px}.c-article-metrics__heading a,.c-article-metrics__posts .c-card__title a{color:inherit}.c-article-metrics__body{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.c-article-metrics__section--left{font-size:1.6rem;-webkit-flex-shrink:1;-ms-flex-negative:1;flex-shrink:1;-webkit-flex-basis:100%;-ms-flex-preferred-size:100%;flex-basis:100%;list-style:none;margin:0;padding:0}@media only screen and (min-width:768px){.c-article-metrics__section--left{-webkit-flex-basis:60%;-ms-flex-preferred-size:60%;flex-basis:60%}}.c-article-metrics__section--left>li:last-child{margin-right:0}.c-article-metrics__section--left p{line-height:24px}.c-article-metrics__explanation{color:#222;font-size:1.4rem;line-height:24px}@media only screen and (min-width:768px){.c-article-metrics__explanation{padding-left:60px}}@media only screen and (min-width:1024px){.c-article-metrics__explanation{padding-left:80px}}.c-article-metrics__section--right{-webkit-box-flex:0;-webkit-flex-grow:0;-ms-flex-positive:0;flex-grow:0;-webkit-flex-shrink:1;-ms-flex-negative:1;flex-shrink:1}@media only screen and (min-width:768px){.c-article-metrics__section--right{-webkit-flex-basis:40%;-ms-flex-preferred-size:40%;flex-basis:40%}}.c-article-metrics__section-heading{line-height:1.4;margin-bottom:16px;font-weight:700;border-bottom:2px solid #222}.c-article-metrics__access-citation,.c-article-metrics__numbers{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex}.c-article-metrics__numbers{-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;margin-bottom:16px}.c-article-metrics__numbers li{padding-top:8px;padding-right:16px;-webkit-box-flex:1;-webkit-flex-grow:1;-ms-flex-positive:1;flex-grow:1}@media only screen and (min-width:1024px){.c-article-metrics__numbers li{padding-top:0}}.c-article-metrics__access-citation{-webkit-box-orient:vertical;-webkit-box-direction:normal;-webkit-flex-flow:column;-ms-flex-flow:column;flex-flow:column;color:#222}.c-article-metrics__access-citation:nth-child(1){-webkit-box-ordinal-group:3;-webkit-order:2;-ms-flex-order:2;order:2}.c-article-metrics__access-citation:nth-child(2){-webkit-box-ordinal-group:2;-webkit-order:1;-ms-flex-order:1;order:1}.c-article-metrics__access-citation dt{font-size:2.4rem;font-weight:500}.c-article-metrics__access-citation dd{font-size:1.8rem}.c-article-metrics__image img{max-height:128px;max-width:100%;display:block;margin:0 auto;min-width:80px}@media only screen and (min-width:768px){.c-article-metrics__image img{margin:0}}.c-article-metrics__altmetric-donut{padding-bottom:24px}@media only screen and (min-width:540px){.c-article-metrics__altmetric-donut{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}}.c-article-metrics__legend{margin-top:24px}@media only screen and (min-width:540px){.c-article-metrics__legend{margin-top:0}}@media only screen and (min-width:768px){.c-article-metrics__legend{-webkit-flex-basis:75%;-ms-flex-preferred-size:75%;flex-basis:75%;-webkit-box-pack:right;-webkit-justify-content:right;-ms-flex-pack:right;justify-content:right}}.c-article-metrics__legend ul{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap}.c-article-metrics__legend li{-webkit-flex-basis:100%;-ms-flex-preferred-size:100%;flex-basis:100%;padding:8px 0 0 16px}@media only screen and (min-width:768px){.c-article-metrics__legend li{-webkit-box-flex:0;-webkit-flex:0 1 130px;-ms-flex:0 1 130px;flex:0 1 130px}}@supports (display:grid) and (grid-auto-rows:auto){.c-article-metrics__legend ul{display:grid;grid-column-gap:8px;grid-auto-rows:auto;grid-template-columns:repeat(auto-fill,minmax(120px,1fr))}@media only screen and (min-width:540px){.c-article-metrics__legend ul{padding-left:16px;grid-template-columns:repeat(2,50%)}}@media only screen and (min-width:1024px){.c-article-metrics__legend ul{grid-template-columns:repeat(3,33%)}}.c-article-metrics__legend ul li{font-size:1.4rem}}.c-article-metrics__posts .c-card__title{font-size:1.7rem}.c-article-metrics__posts .c-card__title+span{color:#6f6f6f;font-size:1.6rem}.c-article-metrics__posts li{border-bottom:1px solid #d5d5d5;margin-bottom:16px;padding-bottom:16px}.c-article-metrics__posts li:first-child{padding-top:0}.c-article-metrics__altmetric-key{border-radius:50%;display:block;float:left;height:16px;margin-right:8px;width:16px}.c-article-metrics__altmetric-key--twitter{background-color:#2f90b9}.c-article-metrics__altmetric-key--blogs{background-color:#ffc200}.c-article-metrics__altmetric-key--facebook{background-color:#071d70}.c-article-metrics__altmetric-key--googleplus{background-color:#912470}.c-article-metrics__altmetric-key--news{background-color:#b60000}.c-article-metrics__altmetric-key--linkedin{background-color:#00bfff}.c-article-metrics__altmetric-key--reddit{background-color:#b9ddeb}.c-article-metrics__altmetric-key--f1000{background-color:#cb2d2d}.c-article-metrics__altmetric-key--pinterest{background-color:#c30}.c-article-metrics__altmetric-key--qna{background-color:#efefef}.c-article-metrics__altmetric-key--video{background-color:#98c973}.c-article-metrics__altmetric-key--wikipedia{background-color:#c7c7c7}.c-article-metrics__altmetric-key--reviews{background-color:#d45bb0}.c-article-metrics__altmetric-key--citeulike{background-color:#bcd2ef}.c-article-metrics__altmetric-key--mendeley{background-color:#a60000}.c-article-metrics__altmetric-key--connotea{background-color:#ff4040}.c-article-metrics__altmetric-key+span{display:block;margin-left:calc(16px + 8px)}@media only screen and (min-width:768px){.js .c-ad{display:block}}.c-popup{position:absolute;font-family:Harding,Palatino,serif;z-index:100;padding:16px;border:1px solid #eee;-webkit-box-shadow:rgba(0,0,0,.1) 1px 1px 10px;box-shadow:rgba(0,0,0,.1) 1px 1px 10px;min-width:300px;max-width:650px;border-radius:2px;background-color:#fff}.c-popup__close{position:absolute;display:block;top:16px;right:16px;height:16px;background:url("data:image/svg+xml,%0A%3Csvg height='16' viewBox='0 0 16 16' width='16' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='m2.29679575 12.2772478c-.39658757.3965876-.39438847 1.0328109-.00062148 1.4265779.39651227.3965123 1.03246768.3934888 1.42657791-.0006214l4.27724782-4.27724787 4.2772478 4.27724787c.3965876.3965875 1.0328109.3943884 1.4265779.0006214.3965123-.3965122.3934888-1.0324677-.0006214-1.4265779l-4.27724787-4.2772478 4.27724787-4.27724782c.3965875-.39658757.3943884-1.03281091.0006214-1.42657791-.3965122-.39651226-1.0324677-.39348875-1.4265779.00062148l-4.2772478 4.27724782-4.27724782-4.27724782c-.39658757-.39658757-1.03281091-.39438847-1.42657791-.00062148-.39651226.39651227-.39348875 1.03246768.00062148 1.42657791l4.27724782 4.27724782z' fill='%23666' fill-rule='evenodd'/%3E%3C/svg%3E") no-repeat;padding-right:16px;text-indent:-9999em}.c-popup__arrow{width:30px;height:20px;position:absolute}.c-popup__arrow--above{bottom:-20px;background:url(data:image/png;base64,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) no-repeat 0 0}.c-popup__arrow--below{top:-20px;background:url(data:image/gif;base64,R0lGODlhHgAUAPMJAOTl5+3t7+/w8t/g4ujp6vHy9Orr7eXm6P///wAAAAAAAAAAAAAAAAAAAAAAAAAAACH/C1hNUCBEYXRhWE1QAT8AIfkEBQAACQAsAAAAAB4AFAAABEcwyUmrvTjrzbv/YCiOZGkmx3FSh4Coa4vMcHkY81zU4gHkOQLvcwgAgYEhp3g8JonG5jHVYUqbA2XFem0+Mdxuk2oJi721CAA7) no-repeat 0 0}.u-display-none{display:none}.js .u-js-hide,.u-hide{display:none;visibility:hidden}.js .u-js-show,.u-show{display:block;visibility:visible}.js .js-authors-expanded .js-author-etal,.js .u-js-show-inline,.u-show-inline{display:inline;visibility:visible}.js .u-js-visually-hidden,.u-visually-hidden{border:0;clip:rect(0,0,0,0);height:1px;margin:-100%;overflow:hidden;padding:0;position:absolute!important;width:1px}.js .u-js-visually-hidden--off,.u-visually-hidden--off{border:0;clip:initial;height:auto;margin:0;overflow:auto;padding:0;position:relative;width:auto}.u-invisible{visibility:hidden}.js .u-js-hide-text,.u-hide-text{text-indent:100%;white-space:nowrap;overflow:hidden;direction:ltr;vertical-align:bottom}.u-hide-overflow{overflow:hidden}@media print{.u-hide-print{display:none}}.u-clearfix::after,.u-clearfix::before{content:"";display:table}.u-clearfix::after{clear:both}.u-icon{fill:currentColor;-webkit-transform:translate(0,0);transform:translate(0,0);display:inline-block;vertical-align:text-top}.u-float-right{float:right}.u-float-left{float:left}.u-list-style-number{list-style-type:decimal}.u-list-style-bullet{list-style-type:disc}.u-list-style-none{list-style-type:none}.u-list-inline,.u-list-reset{list-style:none;margin:0;padding:0}.u-list-comma-separated>li,.u-list-inline>li{display:inline}.u-custom-list-number{float:left;width:3em;padding-right:.5em;margin-left:-3.5em;text-align:right}.u-list-comma-separated{list-style:none;margin:0;padding:0}.u-list-comma-separated>li:not(:first-child):not(:last-child)::before{content:', '}.u-list-comma-separated>li:not(:only-child):last-child::before{content:' & '}.u-list-truncated>li:not(:only-child):last-child::before{content:' ... '}.u-monospace{font-family:monospace}.u-sans-serif{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.u-serif{font-family:Harding,Palatino,serif}.u-small-caps{font-size:.8em;text-transform:uppercase}.u-text-right{text-align:right}.u-text-left{text-align:left}.u-text-center{text-align:center}.u-double-underline{text-decoration:underline;-webkit-text-decoration-skip:ink;text-decoration-skip-ink:auto;border-bottom:1px solid}.u-text-font-smoothing{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.u-word-wrap{word-wrap:break-word;overflow-wrap:break-word;word-break:break-word}.u-upper{text-transform:uppercase}.u-lower{text-transform:lowercase}.u-capitalize{text-transform:capitalize}.u-underline,a:hover{text-decoration:underline;-webkit-text-decoration-skip:ink;text-decoration-skip-ink:auto}.u-unstyled{font-weight:400;font-style:normal}.u-h1{font-size:3.2rem}.u-h2{font-size:2.4rem}.u-h3{font-size:2rem}.u-h4{font-size:1.8rem}.u-overflow-hidden{overflow:hidden}.u-overflow-visible{overflow:visible}html:not(.js) .leaderboard-or-billboard-container{display:none}.c-article-section__title,.c-article-title{font-weight:700}@media screen and (min-width:876px){.background-brand-secondary-pdf{display:none}.sticky-header .background-brand-secondary-pdf{display:block}}.c-article__button{background-color:#069;border:1px solid #069;border-radius:2px;color:#fff;font-size:1.4rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;line-height:1.4;margin-bottom:16px;padding:13px;-webkit-transition:background-color .2s ease-out,color .2s ease-out;transition:background-color .2s ease-out,color .2s ease-out;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex}.c-article__button,.c-article__button:hover{text-decoration:none}.c-article__button--inverted,.c-article__button:hover{background-color:#fff;color:#069}.c-article__button--inverted:hover{background-color:#069;color:#fff}.c-access-options{margin:16px 0 40px}.c-access-options__heading,tfoot td{font-weight:700}.c-access-options__list{margin:0;padding:0;list-style:disc inside}.c-access-options__list>li,.c-author-also-published{font-size:1.6rem;line-height:1.4}.c-author-also-published{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;list-style:none;margin-bottom:0;padding:0}.c-author-also-published>span{background:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'125%2025%2016%2016'%20enable-background%3D'new%20125%2025%2016%2016'%3E%3Cpath%20fill%3D'%23215F90'%20d%3D'M133%2025c-4.374%200-8%203.626-8%208s3.626%208%208%208%208-3.626%208-8-3.626-8-8-8zm1.173%2012.48c0%20.107%200%20.32-.32.32h-1.707c-.213%200-.32-.106-.32-.32v-5.76c0-.213.106-.32.32-.32h1.707c.213%200%20.32.213.32.32v5.76zM133%2030.333c-1.067%200-1.173-.534-1.173-1.067%200-.64.213-1.066%201.173-1.066s1.173.426%201.173%201.066c0%20.534-.106%201.067-1.173%201.067z'%2F%3E%3C%2Fsvg%3E") no-repeat 0 50%;padding-left:24px}fieldset{border:0}a:focus,button:focus,input:focus,select:focus{outline:3px solid #fece3e}a:active,button:active{outline:0}blockquote,body,button,code,dd,div,dl,dt,fieldset,form,input,legend,pre,small,td,textarea,th{margin:0;padding:0}h1,h2,h3,h4,h5,h6,p{padding:0}td,th{padding:4px 7px;border-right:1px solid #d5d5d5;text-align:left;line-height:1.15}th,th[valign=top]{vertical-align:top}td,th[valign=middle]{vertical-align:middle}thead tr{border-bottom:1px solid #d5d5d5}tbody tr{border-top:1px solid #d5d5d5}th{background:#eee}tfoot tr{border-top:2px solid #d5d5d5}body{font-size:1.8em}p{margin:0 0 28px}ol,ul{margin-top:0;margin-bottom:28px}h1{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;line-height:1.3;font-size:3.2rem;margin:0 0 24px}h1,h2,h3{font-family:Harding,Palatino,serif}h2{font-size:2.4rem}h2,h3,h4,h5,h6{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;line-height:1.3;margin:0 0 8px}h3{font-size:2rem}h4,h5,h6{font-size:1.8rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}p:empty{display:none}.box-sizing{-webkit-box-sizing:border-box;box-sizing:border-box}.flex-box{display:inline-block;display:-webkit-flex;display:-webkit-box;display:-ms-flexbox;display:flex}.flex-wrap{-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap}.grid,.grid-ng{float:left;padding-left:0!important;padding-right:0!important}.container{margin:0}.pin-right{float:right}.pin-left{float:left}.clear-float{float:none}.position-absolute{position:absolute}.position-relative{position:relative}.position-top{top:0}.position-right{right:0}.block{display:block}.inline-block{display:inline-block}.c-breadcrumbs>li,.c-footer__list--inline>li,.inline,.inline-list>dd,.inline-list>dt,.inline-list>li{display:inline}.inline-group{font-size:0}.inline-group-top{vertical-align:top}.cleared:after,.cleared:before{content:' ';display:table}.clear,.cleared:after{clear:both}.hide{visibility:hidden}.grade-a-hide,.js .js-hide{display:none;visibility:hidden}.js .js-show,.show{display:block;visibility:visible}.js .js-visually-hidden,.visually-hidden{width:1px;height:1px;position:absolute!important;clip:rect(1px,1px,1px,1px)}.hide-text,.js .js-hide-text{display:block;text-indent:-9999em;direction:ltr;overflow:hidden}.hide-overflow{overflow:hidden}.text-center{text-align:center}.lower{text-transform:lowercase}.nowrap{white-space:nowrap}.overflow-ellipsis{-ms-text-overflow:ellipsis;text-overflow:ellipsis}.unstyled{font-weight:400;font-style:normal}.search-btn{width:4rem;min-width:40px;height:4rem;min-height:40px;font-size:1.2rem;background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'0%200%2016%2016'%3E%3Cpath%20fill%3D'%23fff'%20d%3D'M10.6%201.3c2.3%200%204.2%201.9%204.2%204.2s-1.9%204.2-4.2%204.2-4.2-2-4.2-4.3%201.9-4.1%204.2-4.1m0-1.3c-3%200-5.4%202.4-5.4%205.4s2.4%205.4%205.4%205.4%205.4-2.4%205.4-5.4-2.4-5.4-5.4-5.4zm-3.5%2011.1l-4.9%204.9-2.2-2.2%204.9-4.8%202.2%202.1z'%2F%3E%3C%2Fsvg%3E"),none;background-size:40% auto;background-color:#069;border:1px solid #069;color:transparent}.search-btn:focus,.search-btn:hover{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'0%200%2016%2016'%3E%3Cpath%20fill%3D'%23069'%20d%3D'M10.6%201.3c2.3%200%204.2%201.9%204.2%204.2s-1.9%204.2-4.2%204.2-4.2-2-4.2-4.3%201.9-4.1%204.2-4.1m0-1.3c-3%200-5.4%202.4-5.4%205.4s2.4%205.4%205.4%205.4%205.4-2.4%205.4-5.4-2.4-5.4-5.4-5.4zm-3.5%2011.1l-4.9%204.9-2.2-2.2%204.9-4.8%202.2%202.1z'%2F%3E%3C%2Fsvg%3E"),none;background-color:#fff}.ie9 .search-btn{background-size:16px auto}@media screen and (-ms-high-contrast:active),(-ms-high-contrast:none){.search-btn{background-size:16px auto}}.content{max-width:1000px;margin:0 auto}.article-page{background:#fff}.z-index-100{z-index:100}.z-index-50{z-index:50}.z-index-1{z-index:1}.composite-layer{-webkit-transform:translateZ(0);transform:translateZ(0)}.grid,.grid-inline{margin-right:3.2%}.last{margin-right:0}.grid-2{width:14%}.grid-3{width:22.6%}.grid-4{width:31.2%}.grid-5{width:39.8%}.grid-6{width:48.4%}.grid-7{width:57%}.grid-8{width:65.6%}.grid-9{width:74.2%}.grid-12{width:100%}.grid-left-2{margin-left:17.2%}.grid-1of4{width:25%}.grid-1of3{width:33.3334%;width:calc(100%/3)}.grid-1of2{width:50%}.standard-space-below{margin-bottom:28px}.serif{font-family:Harding,Palatino,serif}.optanon-alert-box-body p,.optanon-alert-box-wrapper .optanon-button-more .optanon-alert-box-button-middle a,.sans-serif{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.strong{font-weight:700;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.emphasis{font-style:italic}.contrast-text,.contrast-text a{color:#fff}.text-gray{color:#222}.text-gray-light{color:#666}.text-orange{color:#cc4b14}.equalize-line-height{line-height:1em}.extra-tight-line-height{line-height:1.3}.tighten-line-height{line-height:1.4}.text11{font-size:1.1rem}.text13{font-size:1.3rem}.text14{font-size:1.4rem}.text15{font-size:1.5rem}.border-gray,.border-gray-medium{border-style:solid;border-width:0;border-color:#999}.border-gray-medium{border-color:#dadada}.border-all-1{border-width:1px}.border-top-1{border-top-width:1px}.border-bottom-1{border-bottom-width:1px}.border-bottom-2{border-bottom-width:2px}.kill-border{border-width:0}.kill-top-border:first-child{border:0}.kill-bottom-border:last-child{border:0}.background-white,a.small-header-icons.tray-button-active,a.small-header-icons:hover,body,body[class*=email-correspondent]{background-color:#fff}.background-gray-dark{background-color:#333}.background-bluegray{background-color:#5a5a62}[data-hellip]{max-height:12.5rem;overflow:hidden}@media only screen and (max-width:54.688em){[data-hellip]{max-height:15rem;overflow:hidden}}.ma0{margin:0}.ma1{margin:1px}.ma2{margin:2px}.ma4{margin:4px}.ma6{margin:6px}.ma10{margin:10px}.ma15{margin:15px}.ma20{margin:20px}.ma30{margin:30px}.ma40{margin:40px}.ma50{margin:50px}.ma70{margin:70px}.mt0{margin-top:0}.mt1{margin-top:1px}.mt2{margin-top:2px}.mt4{margin-top:4px}.mt6{margin-top:6px}.mt10{margin-top:10px}.mt15{margin-top:15px}.mt20{margin-top:20px}.mt30{margin-top:30px}.mt40{margin-top:40px}.mt50{margin-top:50px}.mt70{margin-top:70px}.mr0{margin-right:0}.mr1{margin-right:1px}.mr2{margin-right:2px}.mr4{margin-right:4px}.mr6{margin-right:6px}.mr10{margin-right:10px}.mr15{margin-right:15px}.mr20{margin-right:20px}.mr30{margin-right:30px}.mr40{margin-right:40px}.mr50{margin-right:50px}.mr70{margin-right:70px}.mb0{margin-bottom:0}.mb1{margin-bottom:1px}.mb2{margin-bottom:2px}.mb4{margin-bottom:4px}.mb6{margin-bottom:6px}.mb10{margin-bottom:10px}.mb15{margin-bottom:15px}.mb20{margin-bottom:20px}.mb30{margin-bottom:30px}.mb40{margin-bottom:40px}.mb50{margin-bottom:50px}.mb70{margin-bottom:70px}.mb120{margin-bottom:120px}.ml0{margin-left:0}.ml1{margin-left:1px}.ml2{margin-left:2px}.ml4{margin-left:4px}.ml6{margin-left:6px}.ml10{margin-left:10px}.ml15{margin-left:15px}.ml20{margin-left:20px}.ml30{margin-left:30px}.ml40{margin-left:40px}.ml70{margin-left:70px}.mli{margin-left:.5em}.mri{margin-right:.5em}.mt-grid-match{margin-top:3.2%}.mr-grid-match{margin-right:3.2%}.mb-grid-match{margin-bottom:3.2%}.ml-grid-match{margin-left:3.2%}.ma-grid-match{margin:3.2%}.mr-negative-6{margin-right:-6px}.mt-negative-20{margin-top:-20px}.mt-negative-30{margin-top:-30px}.mb-negative-2{margin-bottom:-2px}.pa0{padding:0}.pa1{padding:1px}.pa2{padding:2px}.pa4{padding:4px}.pa6{padding:6px}.pa10{padding:10px}.pa15{padding:15px}.pa20{padding:20px}.pa25{padding:25px}.pa30{padding:30px}.pa40{padding:40px}.pa70{padding:70px}.pt0{padding-top:0}.pt1{padding-top:1px}.pt2{padding-top:2px}.pt4{padding-top:4px}.pt6{padding-top:6px}.pt10{padding-top:10px}.pt15{padding-top:15px}.pt20{padding-top:20px}.pt25{padding-top:25px}.pt30{padding-top:30px}.pt40{padding-top:40px}.pt70{padding-top:70px}.pr0{padding-right:0}.pr1{padding-right:1px}.pr2{padding-right:2px}.pr4{padding-right:4px}.pr6{padding-right:6px}.pr10{padding-right:10px}.pr15{padding-right:15px}.pr20{padding-right:20px}.pr25{padding-right:25px}.pr30{padding-right:30px}.pr40{padding-right:40px}.pr70{padding-right:70px}.pb0{padding-bottom:0}.pb1{padding-bottom:1px}.pb2{padding-bottom:2px}.pb4{padding-bottom:4px}.pb6{padding-bottom:6px}.pb10{padding-bottom:10px}.pb15{padding-bottom:15px}.pb20{padding-bottom:20px}.pb25{padding-bottom:25px}.pb30{padding-bottom:30px}.pb40{padding-bottom:40px}.pb70{padding-bottom:70px}.pl0{padding-left:0}.pl1{padding-left:1px}.pl2{padding-left:2px}.pl4{padding-left:4px}.pl6{padding-left:6px}.pl10{padding-left:10px}.pl15{padding-left:15px}.pl20{padding-left:20px}.pl25{padding-left:25px}.pl30{padding-left:30px}.pl40{padding-left:40px}.pl70{padding-left:70px}@media only screen and (max-width:75em){.mq1200-padded{padding-left:20px;padding-right:20px}.mq1200-pl0{padding-left:0}.mq1200-pl20{padding-left:20px}}@media only screen and (max-width:54.688em){.mq875-ml0{margin-left:0}.mq875-mb20{margin-bottom:20px}.mq875-mt20{margin-top:20px}.mq875-mt30{margin-top:30px}.mq875-pa0{padding:0}.mq875-pl0{padding-left:0}.mq875-pl20{padding-left:20px}.mq875-pr20{padding-right:20px}.mq875-pb10{padding-bottom:10px}}@media only screen and (max-width:40em){.mq640-pa4{padding:4px}.mq640-pt10{padding-top:10px}.mq640-pb10{padding-bottom:10px}.mq640-pt20{padding-top:20px}.mq640-pl20{padding-left:20px}.mq640-pl0{padding-left:0}.mq640-pr5{padding-right:5px}.mq640-pr20{padding-right:20px}.mq640-pb30{padding-bottom:30px}.mq640-mt0{margin-top:0}.mq640-ml0{margin-left:0}.mq640-mb0{margin-bottom:0}.mq640-mb5{margin-bottom:5px}.mq640-mt20{margin-top:20px}.mq640-mb20{margin-bottom:20px}.mq640-mb30{margin-bottom:30px}}@media only screen and (max-width:30em){.mq480-mr0{margin-right:0}.mq480-mb10{margin-bottom:10px}.mq480-pt10{padding-top:10px}}.js .js-author-etal{display:none;visibility:hidden}@media only screen and (max-width:75em){.js .js-mq1200-hide,.mq1200-hide{display:none;visibility:hidden}.js .js-mq1200-show,.mq1200-show{display:block;visibility:visible}.js .js-mq1200-show-inline,.mq1200-show-inline{display:inline;visibility:visible}.mq1200-visually-show{clip:auto;height:auto;position:static!important;width:auto}}@media only screen and (max-width:54.688em){.js .js-mq875-hide,.mq875-hide{display:none;visibility:hidden}.js .js-mq875-show,.mq875-show{display:block;visibility:visible}.js .js-mq875-show-inline,.mq875-show-inline{display:inline;visibility:visible}.mq875-visually-show{clip:auto;height:auto;position:static!important;width:auto}}@media only screen and (max-width:40em){.js .js-mq640-hide,.mq640-hide{display:none;visibility:hidden}.js .js-mq640-show,.mq640-show{display:block;visibility:visible}.js .js-mq640-show-inline,.mq640-show-inline{display:inline;visibility:visible}.mq640-visually-show{clip:auto;height:auto;position:static!important;width:auto}}@media only screen and (max-width:30em){.js .js-mq480-hide,.mq480-hide{display:none;visibility:hidden}.js .js-mq480-show,.mq480-show{display:block;visibility:visible}.js .js-authors-expanded .js-smaller-author-etal,.js .js-mq480-show-inline,.mq480-show-inline{display:inline;visibility:visible}.mq480-visually-show{clip:auto;height:auto;position:static!important;width:auto}.js .js-smaller-author-etal{display:none;visibility:hidden}}.leaderboard-or-billboard-container{min-height:90px;max-width:100%;line-height:0;word-spacing:0}@media only screen and (min-width:728px){.leaderboard-container{height:90px}}@media only screen and (max-width:728px){.container-type-banner-advert,.leaderboard-container,.leaderboard-or-billboard-container{display:none}}@supports ((-webkit-writing-mode:vertical-rl) or (writing-mode:vertical-rl)){.ad-with-label:after,.ad-with-label:before{content:'Advertisement';color:#fff;background:#999;font-size:9px;line-height:13px;font-family:arial,sans-serif;text-transform:uppercase;position:absolute;word-spacing:0;max-height:100%;top:0;bottom:0}.ad-with-label:before{border-right:1px solid #fff;left:-15px;-webkit-writing-mode:vertical-rl;-ms-writing-mode:tb-rl;writing-mode:vertical-rl}.ad-with-label:after{border-left:1px solid #fff;right:-14px;-webkit-writing-mode:vertical-lr;-ms-writing-mode:tb-lr;writing-mode:vertical-lr}}@media only screen and (max-width:756px){.ad-with-label:after,.ad-with-label:before{display:none}}.billboard-inner iframe{max-height:250px}.leaderboard-container embed,.leaderboard-container iframe,.leaderboard-container img,.leaderboard-container object{max-height:90px}@media only screen and (max-width:45.75em){.leaderboard-container embed,.leaderboard-container object{display:none}}.icon{background-repeat:no-repeat}.icon-right{background-position:100% 50%}.icon-above{background-position:50% 0;padding-top:25px;min-width:25px}.icon-center{background-position:50% 50%}.icon-rotate-left:before,.icon-rotate:after{content:'';position:absolute;background-repeat:no-repeat;background-position:0 0;top:50%;-webkit-transform:translateY(-50%);transform:translateY(-50%);-webkit-transition-duration:.2s;transition-duration:.2s}.icon-rotate:after{right:0}.icon-rotate-left:before{left:0}.js-icon-toggle.icon-rotate-left:before,.js-icon-toggle.icon-rotate:after{-webkit-transform:rotate(180deg) translateY(50%);transform:rotate(180deg) translateY(50%)}.icon-login-25x25-white,.icon-search-25x25-white{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'25'%20height%3D'25'%20viewBox%3D'138.481%2015.385%2025%2025'%20enable-background%3D'new%20138.481%2015.385%2025%2025'%3E%3Cpath%20fill%3D'%23fff'%20d%3D'M150.98%2024.757c2.604%200%204.687-2.083%204.687-4.686s-2.083-4.685-4.686-4.685c-2.603%200-4.685%202.083-4.685%204.686s2.083%204.687%204.686%204.687zm4.79%201.562c-2.498%200-2.394%204.998-4.79%204.998-2.395%200-2.29-5-4.79-5s-6.143%203.958-6.143%209.27c0%205.102%205.832%204.79%2010.934%204.79s10.935.416%2010.935-4.687c0-5.31-3.644-9.37-6.144-9.37z'%2F%3E%3C%2Fsvg%3E"),none;background-size:25px auto}a.small-header-icons:hover .icon-login-25x25-gray{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'25'%20height%3D'25'%20viewBox%3D'0%200%2025%2025'%3E%3Cpath%20fill%3D'%235A5A62'%20d%3D'M12.5%209.372c2.603%200%204.686-2.083%204.686-4.687C17.186%202.082%2015.103%200%2012.5%200S7.813%202.083%207.813%204.687c0%202.603%202.083%204.687%204.687%204.687v-.002zm4.788%201.562c-2.498%200-2.394%204.998-4.79%204.998s-2.29-5-4.79-5-6.143%203.96-6.143%209.27c0%205.104%205.832%204.79%2010.934%204.79%205.102%200%2010.935.417%2010.935-4.687%200-5.31-3.645-9.37-6.145-9.37h-.002z'%2F%3E%3C%2Fsvg%3E"),none;color:#5a5a62}.icon-search-25x25-white{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'25'%20height%3D'25'%20viewBox%3D'235%2015%2025%2025'%20enable-background%3D'new%20235%2015%2025%2025'%3E%3Cg%20fill%3D'%23fff'%3E%3Cpath%20d%3D'M251.583%2017c3.583%200%206.583%203%206.583%206.583s-3%206.583-6.583%206.583-6.583-3-6.583-6.583S248%2017%20251.583%2017m0-2c-4.667%200-8.417%203.75-8.417%208.417s3.75%208.417%208.417%208.417S260%2028.167%20260%2023.417%20256.25%2015%20251.583%2015zM246.083%2032.333L238.417%2040%20235%2036.583l7.667-7.666z'%2F%3E%3C%2Fg%3E%3C%2Fsvg%3E"),none}a.small-header-icons.tray-button-active .icon-search-25x25-gray,a.small-header-icons:hover .icon-search-25x25-gray{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'25'%20height%3D'25'%20viewBox%3D'0%200%2025%2025'%3E%3Cpath%20fill%3D'%235A5A62'%20d%3D'M16.583%202c3.583%200%206.583%203%206.583%206.583s-3%206.583-6.583%206.583S10%2012.166%2010%208.583%2013%202%2016.583%202m0-2c-4.667%200-8.417%203.75-8.417%208.417s3.75%208.417%208.417%208.417S25%2013.167%2025%208.417%2021.25%200%2016.583%200zm-5.5%2017.333L3.417%2025%200%2021.583l7.667-7.666%203.416%203.416z'%2F%3E%3C%2Fsvg%3E"),none;color:#5a5a62}.icon-ealert-25x25-white,.icon-submit-25x25-white{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'25'%20height%3D'25'%20viewBox%3D'0%200%2025%2025'%3E%3Cpath%20fill%3D'%23fff'%20d%3D'M15.6%201.3v5.3h5.3v17h-17v-22.3h11.7m1.4-1.3h-14.3v25h19.6v-19.6h-5.4l.1-5.4zm-.6%201.3l4.6%204.6v17.7h-17v-22.3h12.4m.6-1.3h-14.3v25h19.6v-19.6l-5.3-5.4zM16.6%2013.5l-3.1-3.1-.8-.8c-.1-.1-.3-.1-.4%200l-.8.8-3.1%203.1-.7.7c-.1.1-.2.2-.2.3s.1.2.2.2h2.7c.1%200%20.2.1.2.2v3.3c0%20.2.2.4.4.4h3c.2%200%20.4-.2.4-.4v-3.3c0-.1.1-.2.2-.2h2.7c.1%200%20.2-.1.2-.2s-.1-.3-.2-.4c-.1-.1-.4-.3-.7-.6z'%2F%3E%3C%2Fsvg%3E"),none;background-size:25px auto}a.small-header-icons:hover .icon-submit-25x25-gray{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'25'%20height%3D'25'%20viewBox%3D'0%200%2025%2025'%3E%3Cpath%20fill%3D'%235A5A62'%20d%3D'M15.6%201.3v5.3h5.3v17h-17V1.3h11.7M17%200H2.7v25h19.6V5.4h-5.4L17%200zm-.6%201.3L21%205.9v17.7H4V1.3h12.4M17%200H2.7v25h19.6V5.4L17%200zm-.4%2013.5l-3.1-3.1-.8-.8c-.1-.1-.3-.1-.4%200l-.8.8-3.1%203.1-.7.7c-.1.1-.2.2-.2.3s.1.2.2.2h2.7c.1%200%20.2.1.2.2v3.3c0%20.2.2.4.4.4h3c.2%200%20.4-.2.4-.4v-3.3c0-.1.1-.2.2-.2h2.7c.1%200%20.2-.1.2-.2s-.1-.3-.2-.4c-.1-.1-.4-.3-.7-.6z'%2F%3E%3C%2Fsvg%3E"),none;color:#5a5a62}.icon-ealert-25x25-white{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'25'%20height%3D'25'%20viewBox%3D'0%200%2025%2025'%3E%3Cpath%20fill%3D'%23fff'%20d%3D'M25%203.1h-25v18.8h25v-18.8zm-17.8%2012.8l-3.9%204.4c-.2.2-.5.3-.6.3-.2%200-.5-.2-.6-.3-.3-.3-.3-.9%200-1.4l3.9-4.4c.3-.3.9-.3%201.3%200%20.2.5.2%201.1-.1%201.4zm5.3-.9c-.2%200-.3%200-.5-.2l-9.8-8.9c-.5-.3-.5-.7-.2-1.1.3-.5.8-.5%201.1-.2l9.4%208.4%209.4-8.4c.3-.3.8-.3%201.1.2.3.3.3.9-.2%201.1l-9.7%208.9c-.1.2-.4.2-.6.2zm10.5%205.3c-.2.2-.5.3-.6.3s-.5-.2-.6-.3l-4.1-4.4c-.3-.3-.3-.9%200-1.4.3-.3.9-.3%201.3%200l4.1%204.4c.2.5.2%201.1-.1%201.4z'%2F%3E%3C%2Fsvg%3E"),none}a.small-header-icons:hover .icon-ealert-25x25-gray{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'25'%20height%3D'25'%20viewBox%3D'0%200%2025%2025'%3E%3Cpath%20fill%3D'%235A5A62'%20d%3D'M25%203.1H0v18.8h25V3.1zM7.2%2015.9l-3.9%204.4c-.2.2-.5.3-.6.3-.2%200-.5-.2-.6-.3-.3-.3-.3-.9%200-1.4L6%2014.5c.3-.3.9-.3%201.3%200%20.2.5.2%201.1-.1%201.4zm5.3-.9c-.2%200-.3%200-.5-.2L2.2%205.9c-.5-.3-.5-.7-.2-1.1.3-.5.8-.5%201.1-.2l9.4%208.4%209.4-8.4c.3-.3.8-.3%201.1.2.3.3.3.9-.2%201.1l-9.7%208.9c-.1.2-.4.2-.6.2zM23%2020.3c-.2.2-.5.3-.6.3-.1%200-.5-.2-.6-.3l-4.1-4.4c-.3-.3-.3-.9%200-1.4.3-.3.9-.3%201.3%200l4.1%204.4c.2.5.2%201.1-.1%201.4z'%2F%3E%3C%2Fsvg%3E"),none;color:#5a5a62}.icon-close-12x12-gray{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'12'%20viewBox%3D'0%200%2012%2012'%3E%3Cpath%20fill%3D'%23666666'%20d%3D'M1.8%2012l-1.7-1.7%2010.2-10.3%201.7%201.7-10.2%2010.3zm10.1-1.7l-1.7%201.7-10.2-10.3%201.7-1.7%2010.2%2010.3z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.icon-close-12x12-blue,.icon-mail-12x9-blue{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'12'%20viewBox%3D'0%200%2012%2012'%3E%3Cpath%20fill%3D'%23069'%20d%3D'M1.8%2012L.1%2010.3%2010.3%200%2012%201.7%201.8%2012zm10.1-1.7L10.2%2012%200%201.7%201.7%200l10.2%2010.3z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.icon-mail-12x9-blue{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'9'%20viewBox%3D'0%200%2012%209'%3E%3Cpath%20fill%3D'%23006699'%20d%3D'M12%200h-12v9h12v-9zm-8.5%206.1l-1.9%202.1c-.1.2-.2.2-.3.2s-.2-.1-.3-.2c-.2-.1-.2-.4%200-.6l1.9-2.1c.2-.2.5-.2.6%200%20.1.2.1.5%200%20.6zm2.5-.3l-.2-.1-4.8-4.3c-.2-.1-.2-.4%200-.6%200-.1.3-.1.5%200l4.5%204%204.5-4.1c.1-.1.5-.1.5.1.1.1.1.5-.1.5l-4.7%204.3c-.1.1-.1.2-.2.2zm5%202.4c-.1.1-.1.1-.3.1s-.2-.1-.3-.1l-1.9-2.1c-.2-.1-.2-.4%200-.6.2-.2.5-.2.6%200l1.9%202.1c.3.2.3.5%200%20.6z'%2F%3E%3C%2Fsvg%3E"),none}.icon-new-window-16x16{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'16'%20height%3D'16'%20viewBox%3D'0%200%2016%2016'%3E%3Cpath%20fill%3D'%23555'%20d%3D'M14.4%202H5v4H0v8h11v-4h5V2h-1.6zM10%2013H1V9h4v1h5v3zM6%205h9v4H6'%2F%3E%3C%2Fsvg%3E"),none;background-size:16px auto}.icon-arrow-down-12x7-white,.icon-rotate.icon-arrow-down-12x7-white:after{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'7'%20viewBox%3D'0%200%2012%207'%3E%3Cpath%20fill%3D'%23fff'%20d%3D'M9.6%200l-3.6%204.3-3.6-4.3h-2.4l6%207%206-7h-2.4z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.icon-arrow-up-12x7-white,.icon-rotate.icon-arrow-up-12x7-white:after{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'7'%20viewBox%3D'0%200%2012%207'%3E%3Cpath%20fill%3D'%23fff'%20d%3D'M2.4%207l3.6-4.3%203.6%204.3h2.4l-6-7-6%207h2.4z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.icon-arrow-down-12x7-gray,.icon-rotate-left.icon-arrow-down-12x7-gray:before,.icon-rotate.icon-arrow-down-12x7-gray:after,.icon-rotate.tools-menu-button-icon:after,.tools-menu-button-icon{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'7'%20viewBox%3D'0%200%2012%207'%3E%3Cpath%20fill%3D'%23686969'%20d%3D'M9.7%200l-3.7%204.3-3.7-4.3h-2.3l6%207%206-7h-2.3z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.icon-arrow-up-12x7-gray,.icon-rotate.icon-arrow-up-12x7-gray:after{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'7'%20viewBox%3D'0%200%2012%207'%3E%3Cpath%20fill%3D'%23686969'%20d%3D'M2.3%207l3.7-4.3%203.7%204.3h2.3l-6-7-6%207h2.3z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.icon-arrow-down-12x7-blue,.icon-rotate-left.icon-arrow-down-12x7-blue:before,.icon-rotate.icon-arrow-down-12x7-blue:after{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'7'%20viewBox%3D'0%200%2012%207'%3E%3Cpath%20fill%3D'%23069'%20d%3D'M9.6%200l-3.6%204.3-3.6-4.3h-2.4l6%207%206-7h-2.4z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.icon-arrow-up-12x7-blue,.icon-rotate.icon-arrow-up-12x7-blue:after{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'7'%20viewBox%3D'0%200%2012%207'%3E%3Cpath%20fill%3D'%23069'%20d%3D'M2.4%207l3.6-4.3%203.6%204.3h2.4l-6-7-6%207h2.4z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.icon-arrow-right-6x10-white{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'6'%20height%3D'10'%20viewBox%3D'-0.064%20-1.375%206%2010'%20enable-background%3D'new%20-0.064%20-1.375%206%2010'%3E%3Cpath%20fill%3D'%23fff'%20d%3D'M-.064.625l3.686%203-3.686%203v2l6-5-6-5v2z'%2F%3E%3C%2Fsvg%3E"),none;background-size:7px auto}.icon-arrow-left-6x10-blue{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'6'%20height%3D'10'%20viewBox%3D'0%200%206%2010'%3E%3Cpath%20fill%3D'%23069'%20d%3D'M5.936%200l-6%205%206%205v-2l-3.686-3%203.686-3v-2z'%2F%3E%3C%2Fsvg%3E"),none;background-size:7px auto}.icon-rotate-left.icon-arrow-down-12x7-blue,.icon-rotate-left.icon-arrow-down-12x7-gray,.icon-rotate.icon-arrow-down-12x7-blue,.icon-rotate.icon-arrow-down-12x7-gray,.icon-rotate.icon-arrow-down-12x7-white,.icon-rotate.icon-arrow-up-12x7-blue,.icon-rotate.icon-arrow-up-12x7-gray,.icon-rotate.icon-arrow-up-12x7-white,.icon-rotate.tools-menu-button-icon{background-image:none}.icon-rotate-left.icon-arrow-down-12x7-blue:before,.icon-rotate-left.icon-arrow-down-12x7-gray:before,.icon-rotate.icon-arrow-down-12x7-blue:after,.icon-rotate.icon-arrow-down-12x7-gray:after,.icon-rotate.icon-arrow-down-12x7-white:after,.icon-rotate.icon-arrow-up-12x7-blue:after,.icon-rotate.icon-arrow-up-12x7-gray:after,.icon-rotate.icon-arrow-up-12x7-white:after,.icon-rotate.tools-menu-button-icon:after{width:12px;height:7px}.icon-rotate.menu-button-icon:after{margin-top:-1px}.header-tools-link{height:29px}.clean-list{padding:0;list-style:none}@media only screen and (min-width:75.06em){.full-size-last{margin-right:0}.full-size-clear{clear:both}.full-size-kill-left{margin-left:0}}@media only screen and (max-width:75em) and (min-width:54.74em){.just-mq1200-last{margin-right:0}.just-mq1200-clear{clear:both}.just-mq1200-kill-left{margin-left:0}}@media only screen and (max-width:54.688em) and (min-width:40.06em){.just-mq875-last{margin-right:0}.just-mq875-clear{clear:both}.just-mq875-kill-left{margin-left:0}}@media only screen and (max-width:40em) and (min-width:30.06em){.just-mq640-last{margin-right:0}.just-mq640-clear{clear:both}.just-mq640-kill-left{margin-left:0}}@media only screen and (max-width:30em){.just-mq480-last{margin-right:0}.just-mq480-clear{clear:both}.just-mq480-kill-left{margin-left:0}}@media only screen and (max-width:75em){.mq1200-grid-12{width:100%}.mq1200-grid-4{width:31.2%}}@media only screen and (max-width:54.688em){.mq875-grid-12{width:100%}.mq875-grid-10{width:82.8%}.mq875-grid-8{width:65.6%}.mq875-grid-7{width:57%}.mq875-grid-6{width:48.4%}.mq875-grid-4{width:31.2%}.mq875-grid-3{width:22.6%}.mq875-grid-1{width:5.4%}.mq875-kill-left{margin-left:0}}@media only screen and (max-width:40em){.mq640-last{margin-right:0}.mq640-clear{clear:both}.mq640-grid-12{width:100%}.mq640-grid-9{width:74.2%}.mq640-grid-6{width:48.4%}.mq640-grid-4{width:31.2%}.mq640-kill-left{margin-left:0}}@media only screen and (max-width:30em){.mq480-grid-12{width:100%}}.skiplink{width:1px;height:1px;display:block;overflow:hidden;position:absolute}.skiplink:focus{width:auto;height:auto;overflow:visible;margin:2px 0 1px;padding:2px;position:static}.breadcrumbs{padding:0 15px 5px}.breadcrumbs ol{padding:10px 5px 5px;overflow:hidden;line-height:1.1em;white-space:nowrap;text-overflow:ellipsis}.small-header-icons{padding-left:7px;padding-right:7px;margin-top:14px;width:65px}.small-header-icons:hover{text-decoration:none}@media only screen and (max-width:75em){.breadcrumbs{padding:0 15px 5px 0}}.sticky-header{width:100%;height:39px;position:fixed;top:0}.sticky-header .menu-button{top:0;margin:7px 0}.header-logo-container{height:50px;padding:15px 20px}.sticky-header .header-logo-container{padding:7px 0 7px 20px;height:25px}.sticky-header .header-logo{height:25px}.sticky-header .header-logo img{max-height:25px}.sticky-header .small-header-icons{border-left:1px solid #8d8d78;padding:7px 16px;background-color:#5a5a62;margin-top:0;margin-right:0;width:auto}.sticky-header .small-header-icons:first-of-type{border-left:0}.sticky-header .small-header-main{width:auto;margin:0}.nature-research-logo{width:319px;background-position:50% 50%;background-repeat:no-repeat}.nature-pdf-logo{display:block;background-color:#036599;color:#fff;background-position:95% 50%;background-repeat:no-repeat;text-decoration:none}.small-header-side{right:0}.sticky-header .small-header-side{width:auto;float:right;margin:0;position:static}.sticky-header .small-header-hide{position:absolute;width:1px;left:-9999em}@media only screen and (max-width:54.688em){.small-header-hide{position:absolute;width:1px;left:-9999em}}.banner .header-tools-show{display:block;visibility:visible}.header-logo,.header-logo-container{overflow:hidden}.header-logo img{max-height:50px;margin:0;padding:0}.header-logo-primary,.sticky-header .header-logo-secondary{display:inline;visibility:visible}.header-logo-secondary,.sticky-header .header-logo-primary{display:none;visibility:hidden}.menu-button,.menu-button-clone{position:absolute;top:15px;right:100%;padding:6px 10px;border:1px solid #222;border:1px solid rgba(34,34,34,.75);text-transform:uppercase;font-size:1.4rem;color:#222}.menu-button-clone:focus,.menu-button-clone:hover,.menu-button:focus,.menu-button:hover{text-decoration:none}.menu-button-icon{display:block;position:relative;padding-right:15px;text-align:right;background-repeat:no-repeat;background-position:100% 50%}.menu-button-icon:after{width:12px;height:7px;background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'12'%20height%3D'7'%20viewBox%3D'0%200%2012%207'%3E%3Cpath%20fill%3D'%23222'%20d%3D'M9.7%200L6%204.3%202.3%200H0l6%207%206-7H9.7z'%2F%3E%3C%2Fsvg%3E"),none;background-size:12px auto}.menu-button-label{padding-right:4px}.menu-button-icon,.menu-button-label{height:11px;line-height:11px}.menu-button-icon{min-width:45px}@media only screen and (max-width:75em){.small-header-side{right:20px}.menu-button,.sticky-header .menu-button{display:inline-block;float:none;vertical-align:top;position:static;margin:1px 20px 1px 0}.up-next{display:none}.menu-button-icon{min-width:0;padding-right:12px}.menu-button-label{position:absolute;left:-9999em;width:1px}.header-logo-container,.sticky-header .header-logo-container{padding-left:0}.banner{padding-left:20px;padding-right:0}}@media only screen and (max-width:54.688em){.menu-button{margin:1px 20px 1px 0}.header-logo-container{padding:7px 0;height:25px}.header-logo{height:25px}.header-logo img{max-height:25px}.header-logo-primary{display:none;visibility:hidden}.header-logo-secondary{display:inline;visibility:visible}.small-header-icons{border-left:1px solid #8d8d78;margin-top:0;margin-right:0;padding:7px 16px;width:auto;background-color:#5a5a62}.small-header-icons:first-of-type{border-left:0}.small-header-main,.small-header-side{width:auto;margin:0}.small-header-side{float:right;position:static}.nature-research-logo{width:231px;margin-right:-20px}}@media only screen and (max-width:40em){.menu-button,.sticky-header .menu-button{margin-right:4px}.header-logo-primary,.sticky-header .header-logo-primary{display:inline;visibility:visible}.header-logo-secondary,.sticky-header .header-logo-secondary{display:none;visibility:hidden}}.js .menu{position:absolute;overflow-y:auto;left:0;right:0;display:none;margin:0}.js .sticky-header~.menu{position:fixed}.beta-switch,.js .menu-open{display:block}.beta-switch{background-color:#069;color:#fff}.beta-switch a,.beta-switch a:visited{color:#fff;text-decoration:underline;-webkit-text-decoration-skip:ink;text-decoration-skip-ink:auto}@media only screen and (max-width:75em) and (min-width:54.74em){.banner{padding-right:20px}}.optanon-alert-box-body p a{color:#fff;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;text-decoration:underline}.optanon-alert-box-wrapper .optanon-button-more .optanon-alert-box-button-middle a:before{top:0!important}.js-return-btn:focus{width:auto;height:auto;position:static!important;clip:auto}@media only screen and (max-width:40em){.mq640-ml-20{margin-left:-20px}.mq640-mr-20{margin-right:-20px}}.has-fade{--opacity: 1}.has-fade::after{content:'';height:100%;width:30px;background-image:-webkit-gradient(linear,left top,right top,from(rgba(255,255,255,0)),color-stop(rgba(255,255,255,.6)),to(white));background-image:linear-gradient(to right,rgba(255,255,255,0),rgba(255,255,255,.6),white);display:block;position:absolute;right:0;top:0;bottom:0;opacity:var(--opacity);-webkit-transition:opacity .25s ease-in-out;transition:opacity .25s ease-in-out;will-change:opacity}.full-right{margin-right:calc(50% - 49vw)}.scroll-wrapper table{border:solid 2px #dadada}.scroll-wrapper td,.scroll-wrapper th{padding:6px 7px}.metadata-summary td:first-child{font-weight:700}.c-site-messages{color:#fff;background-color:#36454d;border-bottom:3px solid #29363d;padding-bottom:15px;padding-top:15px}.c-site-messages p{line-height:20px;margin-bottom:0}.c-site-messages .c-site-messages__content{display:inline-block;width:89%}.c-site-messages .c-site-messages__close-container{position:relative;text-align:right;display:inline-block;width:10%}.c-site-messages .c-site-messages__close{background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg%20width%3D'21'%20height%3D'21'%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20aria-labelledby%3D'close'%20role%3D'img'%3E%3Ctitle%20id%3D'title'%3EClose%20button%20icon%3C%2Ftitle%3E%3Cpath%20d%3D'M10.5%2012.621l2.727%202.727%201.06%201.06%202.122-2.12-1.06-1.061L12.62%2010.5l2.727-2.727%201.06-1.06-2.12-2.122-1.061%201.06L10.5%208.38l-2.69-2.69-1.06-1.06L4.629%206.75l1.06%201.06%202.69%202.69-2.69%202.69-1.06%201.06%202.121%202.121%201.06-1.06%202.69-2.69zm0%208.379C4.701%2021%200%2016.299%200%2010.5S4.701%200%2010.5%200%2021%204.701%2021%2010.5%2016.299%2021%2010.5%2021z'%20fill%3D'%23fff'%20fill-rule%3D'evenodd'%2F%3E%3C%2Fsvg%3E"),none;background-position:100% 50%;background-repeat:no-repeat;background-size:16px;color:#fff;padding-right:20px}.c-site-messages .c-site-messages__close:hover,.nature-briefing-banner__checkbox-label a:hover{text-decoration:underline}.p-link-button{background:0 0;border:0;cursor:pointer}.c-site-messages--nature-briefing-email-variant{padding-top:15px;padding-bottom:15px}.c-site-messages--nature-briefing-email-variant .js .js-visually-hidden,.c-site-messages--nature-briefing-email-variant .visually-hidden{width:1px;height:1px;position:absolute!important;clip:rect(1px,1px,1px,1px)}.c-site-messages--nature-briefing-email-variant .serif,.c-site-messages--nature-briefing-email-variant.serif{font-family:Harding,Palatino,Times,"Times New Roman",serif}.c-site-messages--nature-briefing-email-variant .sans-serif,.c-site-messages--nature-briefing-email-variant.sans-serif{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.c-site-messages--nature-briefing-email-variant .content{max-width:1280px;margin:0 auto}.c-site-messages--nature-briefing-email-variant .box-sizing{-webkit-box-sizing:border-box;box-sizing:border-box}.c-site-messages--nature-briefing-email-variant .pin-right{float:right}.c-site-messages--nature-briefing-email-variant .text13{font-size:1.3rem}.c-site-messages--nature-briefing-email-variant .text14{font-size:1.4rem}.c-site-messages--nature-briefing-email-variant .block{display:block}.c-site-messages--nature-briefing-email-variant .strong{font-weight:700}.c-site-messages--nature-briefing-email-variant .tighten-line-height{line-height:1.4}.c-site-messages--nature-briefing-email-variant .extra-tight-line-height{line-height:1.3}.c-site-messages--nature-briefing-email-variant .border-gray{border-style:solid;border-width:0;border-color:#999}.c-site-messages--nature-briefing-email-variant .border-all-1{border-width:1px}.c-site-messages--nature-briefing-email-variant .pa10{padding:10px}.c-site-messages--nature-briefing-email-variant .grid{float:left;padding-left:0!important;padding-right:0!important}.c-site-messages--nature-briefing-email-variant .grid,.c-site-messages--nature-briefing-email-variant .grid-inline{margin-right:3.2%}.c-site-messages--nature-briefing-email-variant .last{margin-right:0}.c-site-messages--nature-briefing-email-variant .grid-1{width:5.4%}.c-site-messages--nature-briefing-email-variant .grid-2{width:14%}.c-site-messages--nature-briefing-email-variant .grid-3{width:22.6%}.c-site-messages--nature-briefing-email-variant .grid-4{width:31.2%}.c-site-messages--nature-briefing-email-variant .grid-5{width:39.8%}.c-site-messages--nature-briefing-email-variant .grid-6{width:48.4%}.c-site-messages--nature-briefing-email-variant .grid-7{width:57%}.c-site-messages--nature-briefing-email-variant .grid-8{width:65.6%}.c-site-messages--nature-briefing-email-variant .grid-9{width:74.2%}.c-site-messages--nature-briefing-email-variant .grid-10{width:82.8%}.c-site-messages--nature-briefing-email-variant .grid-11{width:91.4%}.c-site-messages--nature-briefing-email-variant .grid-12{width:100%}.c-site-messages--nature-briefing-email-variant .grid-left-1{margin-left:8.6%}.c-site-messages--nature-briefing-email-variant .grid-right-1{margin-right:8.6%}.c-site-messages--nature-briefing-email-variant .grid-left-2{margin-left:17.2%}.c-site-messages--nature-briefing-email-variant .grid-right-2{margin-right:17.2%}.c-site-messages--nature-briefing-email-variant .grid-left-3{margin-left:25.8%}.c-site-messages--nature-briefing-email-variant .grid-right-3{margin-right:25.8%}.c-site-messages--nature-briefing-email-variant .grid-left-4{margin-left:34.4%}.c-site-messages--nature-briefing-email-variant .grid-right-4{margin-right:34.4%}.c-site-messages--nature-briefing-email-variant .grid-left-5{margin-left:43%}.c-site-messages--nature-briefing-email-variant .grid-right-5{margin-right:43%}.c-site-messages--nature-briefing-email-variant .grid-left-6{margin-left:51.6%}.c-site-messages--nature-briefing-email-variant .grid-right-6{margin-right:51.6%}.c-site-messages--nature-briefing-email-variant .grid-left-7{margin-left:60.2%}.c-site-messages--nature-briefing-email-variant .grid-right-7{margin-right:60.2%}.c-site-messages--nature-briefing-email-variant .grid-left-8{margin-left:68.8%}.c-site-messages--nature-briefing-email-variant .grid-right-8{margin-right:68.8%}.c-site-messages--nature-briefing-email-variant .grid-left-9{margin-left:77.4%}.c-site-messages--nature-briefing-email-variant .grid-right-9{margin-right:77.4%}.c-site-messages--nature-briefing-email-variant .grid-left-10{margin-left:86%}.c-site-messages--nature-briefing-email-variant .grid-right-10{margin-right:86%}.c-site-messages--nature-briefing-email-variant .grid-left-11{margin-left:94.6%}.c-site-messages--nature-briefing-email-variant .grid-right-11{margin-right:94.6%}.c-site-messages--nature-briefing-email-variant .grid-1of4{width:25%}.c-site-messages--nature-briefing-email-variant .grid-1of3{width:33.3334%;width:calc(100%/3)}.c-site-messages--nature-briefing-email-variant .grid-1of2{width:50%}.c-site-messages--nature-briefing-email-variant .grid-3of4{width:75%}.c-site-messages--nature-briefing-email-variant .grid-1of5{width:20%}.c-site-messages--nature-briefing-email-variant .grid-2of5{width:40%}.c-site-messages--nature-briefing-email-variant .grid-3of5{width:60%}.c-site-messages--nature-briefing-email-variant .grid-4of5{width:80%}.c-site-messages--nature-briefing-email-variant .grid-split-margin-left{margin-left:1.6%;padding-left:1.6%!important}.c-site-messages--nature-briefing-email-variant .grid-split-margin-right{margin-right:1.6%;padding-right:1.6%!important}.c-site-messages--nature-briefing{position:fixed;bottom:0;left:0;right:0;width:100%;background-color:#069;color:#fff;-webkit-box-shadow:0 0 10px 0 rgba(51,51,51,.2);box-shadow:0 0 10px 0 rgba(51,51,51,.2);-webkit-transform:translateY(100%);transform:translateY(100%);-webkit-transition:background-color 1s ease-in-out 1.2s,color 1s ease-in-out 1s,-webkit-transform .6s ease-in-out;transition:transform .6s ease-in-out,background-color 1s ease-in-out 1.2s,color 1s ease-in-out 1s,-webkit-transform .6s ease-in-out;border-bottom:none}.c-site-messages--nature-briefing .icon--inline{position:relative;border:0;border-radius:0;padding:10px}.c-site-messages--nature-briefing .icon--inline svg{position:absolute;top:50%;left:50%;margin-right:-50%;-webkit-transform:translate(-50%,-50%);transform:translate(-50%,-50%);width:24px;height:24px}@media only screen and (min-width:960px){.c-site-messages--nature-briefing .icon--inline svg{width:42px;height:42px;padding:10px 20px}}.c-site-messages--nature-briefing .icon--inline path{transition:transform .6s ease-in-out,fill 1s ease-in-out 1.2s,color 1s ease-in-out 1s,-webkit-transform .6s ease-in-out;fill:rgba(255,255,255,.5)}.c-site-messages--nature-briefing .c-site-messages__close{border:0;padding-right:0}.c-site-messages--nature-briefing .c-site-messages__close-container{width:auto;position:relative;text-align:right;display:inline-block}@media only screen and (min-width:960px){.c-site-messages--nature-briefing .c-site-messages__close-container svg{width:25px;height:25px}}.c-site-messages--nature-briefing.c-site-messages .c-site-messages__close{margin-top:3px;background:0 0}@media only screen and (min-width:960px){.c-site-messages--nature-briefing.c-site-messages .c-site-messages__close{margin-top:12px}.c-site-messages--nature-briefing-email-variant.c-site-messages .c-site-messages__banner-large .c-site-messages__close{margin-top:0}}.c-site-messages__banner-large .c-site-messages__close-container{width:100%;float:right;margin-top:-5px}.c-site-messages__banner-large .c-site-messages__form-container{float:none;width:100%}@media only screen and (min-width:768px){.c-site-messages__banner-large .c-site-messages__close-container{width:30px}.c-site-messages__banner-large .c-site-messages__form-container{float:left;width:calc(100% - 30px)}}.c-site-messages--nature-briefing .c-site-messages__close{vertical-align:text-top}.c-site-messages__banner-large .c-site-messages__close{vertical-align:top}.c-site-messages__banner-small .c-site-messages__content{display:inline-block;width:89%}.c-site-messages__banner-small .c-site-messages__close-container{position:relative;text-align:right;display:inline-block;width:10%}.c-site-messages--nature-briefing .nature-briefing__link{text-align:center;text-transform:none;border-radius:unset;background-color:#fff;border:1px solid #fff;color:#069;white-space:normal;font-weight:400;letter-spacing:.5px;padding:10px 15px;display:inline-block;margin-top:10px;transition:transform .6s ease-in-out,border 1s ease-in-out 1s,-webkit-transform .6s ease-in-out}@media only screen and (min-width:960px){.c-site-messages--nature-briefing .nature-briefing__link{margin-left:15px;margin-top:0}}.c-site-messages--is-visible{-webkit-transform:translateY(0);transform:translateY(0);background-color:#fff;color:#222}.c-site-messages--is-visible .icon--inline path{fill:#069}.c-site-messages--is-visible .nature-briefing__link{border:1px solid #069}.c-site-messages--nature-briefing .c-site-messages__close{color:#069}@media only screen and (max-width:700px){.u-hide-on-mobile{display:none}}.nature-briefing-banner__email-input{width:100%;margin-right:1em;border-color:#222}.nature-briefing-banner__checkbox-label{display:inline-block;cursor:pointer;position:relative;padding-left:33px}.nature-briefing-banner__checkbox-label:before{content:"";position:absolute;top:6px;left:0;width:24px;height:24px;border:1px solid currentColor;border-radius:0;background:#fff}.nature-briefing-banner__checkbox-label:after{content:"";position:absolute;top:12px;left:5px;width:14px;height:7px;-webkit-transform:rotate(-45deg);transform:rotate(-45deg);border:solid;border-width:0 0 2px 2px;border-top-color:transparent;opacity:0;background:0 0}.nature-briefing-banner__checkbox-checkbox{font-size:20px;cursor:pointer;position:absolute;z-index:1;top:-2px;left:-2px;width:44px;height:44px;margin:0;opacity:0}.nature-briefing-banner__checkbox-checkbox:checked+.nature-briefing-banner__checkbox-label:after{opacity:1}.nature-briefing-banner__checkbox-checkbox:focus+.nature-briefing-banner__checkbox-label:before,.nature-briefing-banner__submit-button:focus{outline:3px solid #fece3e}.nature-briefing-banner__submit-button{border:1px solid #fff;background:#069;color:#fff;line-height:1.2;font-size:1.6rem;padding:7px 20px;text-align:center;width:auto;float:left;-webkit-transition:border 1s ease-in-out 1s;transition:border 1s ease-in-out 1s}.nature-briefing-banner__submit-button:disabled{background-color:#777;color:#fff}.c-site-messages--is-visible .nature-briefing-banner__submit-button{border:1px solid #069}.nature-briefing-banner__checkbox-label a{color:#fff;font-weight:700;-webkit-transition:color 1s ease-in-out 1s;transition:color 1s ease-in-out 1s}.c-site-messages--is-visible .nature-briefing-banner__checkbox-label a{color:#222}.c-site-messages__banner-large,.c-site-messages__banner-small{margin:0 auto;padding-left:16px;padding-right:16px}.c-site-messages__banner-large{display:none;max-width:1280px}.c-site-messages__banner-large:after,.c-site-messages__banner-large:before{content:" ";display:table}.c-site-messages__banner-large:after{clear:both}.c-site-messages__banner-small{display:block}@media only screen and (min-width:641px){.c-site-messages__banner-large{display:block}.c-site-messages__banner-small{display:none}}.flex-wrap-reverse{-webkit-flex-wrap:wrap-reverse;-ms-flex-wrap:wrap-reverse;flex-wrap:wrap-reverse}.flex-center{-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center}.grade-c-hide{display:block}.grade-c-show{display:none;visibility:hidden}.grade-c-invisible{visibility:visible}.menu-button{float:none}.header-logo-container h1{color:#000;padding:0;background:0 0;line-height:0}.container{max-width:none;padding:unset}.sticky-tabs{max-width:312px}.flex-tab{height:auto;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-orient:horizontal;-webkit-box-direction:normal;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;-webkit-align-content:center;-ms-flex-line-pack:center;align-content:center;-webkit-box-align:stretch;-webkit-align-items:stretch;-ms-flex-align:stretch;align-items:stretch}.flex-tab .tab-like{-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1;-webkit-flex-grow:1;-ms-flex-positive:1;flex-grow:1}@media only screen and (min-width:350px){[data-back-link]{float:left}}.popup--compound{max-width:400px}.popup--compound img{margin:auto}@media only screen and (min-width:40em){.issue-research li:nth-child(-n+2){border-top:0}}.indented-list h4{margin-left:50px}.sticky-header .header-top-bar{border:0;padding:8px 0 0;float:right}.sticky-header .header-journals-services,.sticky-header .header-secondary-links,.sticky-header .hide-when-sticky{display:none}.c-site-messages--nature-briefing{z-index:100001}.header-promo-button{background-color:#036599;margin-top:14px;width:120px}.sticky-header .header-promo-button{border-left:0;padding:7px 16px;margin-top:0;margin-right:0}.sticky-header .header-promo-button .header-promo-text{margin:0;padding-bottom:0}.c-ad{display:none;padding:8px;text-align:center}@media only screen and (min-width:768px){.js .c-ad{display:block}}.c-ad--728x90,.c-ad--970x90{background-color:#ccc}.c-ad--728x90 .c-ad__inner,.c-ad--970x90 .c-ad__inner{min-height:calc(1.5em + 4px + 90px)}.c-ad--728x90 iframe,.c-ad--970x90 iframe{max-width:970px;height:90px}.c-ad--160x600{padding:0;text-align:left}.c-ad--160x600 iframe{width:160px;height:600px}.c-ad--300x250{background-color:#f2f2f2}.c-ad--300x250 iframe{width:300px;height:250px}.c-ad--300x250 .c-ad__inner{min-height:calc(1.5em + 4px + 250px)}.c-ad iframe{border:0;overflow:auto;vertical-align:top}.c-ad__label,.c-menu{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif}.c-ad__label{font-weight:400;margin-bottom:4px;color:#333;font-size:1.4rem;line-height:1.5}.c-menu{list-style:none;margin:0;padding:0;font-size:1.6rem;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;line-height:1.3}.c-menu__item:not(:last-child){margin-right:16px}.c-menu__link{display:inline-block;text-decoration:none;color:inherit}.c-menu__link:active,.c-menu__link:visited{color:inherit}.c-menu__link:hover{text-decoration:underline}.c-menu--small{font-size:1.4rem}.c-menu--vertical{-webkit-box-orient:vertical;-webkit-box-direction:normal;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column}.c-menu--vertical .c-menu__item:not(:last-child){margin-bottom:16px;margin-left:0}.c-menu--keyline .c-menu__item:not(:last-child){margin-right:16px;padding-right:16px;border-right:1px solid #eee}.c-menu--vertical.c-menu--keyline .c-menu__item:not(:last-child){margin:0 0 16px;padding:0 0 16px;border-right:none;border-bottom:1px solid #eee}.c-menu--padded .c-menu__item:not(:last-child),.c-menu--padded.c-menu--keyline .c-menu__item:not(:last-child),.c-menu--vertical.c-menu--padded .c-menu__item:not(:last-child){margin:0;padding:0}.c-menu--padded .c-menu__link{padding:16px;display:block}.c-menu--padded .c-menu__link:hover{background-color:#eee}.c-menu--inherit .c-menu__link,.c-menu--inherit .c-menu__link.hover,.c-menu--inherit .c-menu__link.visited,.c-menu--inherit .c-menu__link:hover,.c-menu--inherit .c-menu__link:visited{color:inherit}.c-button{-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;cursor:pointer;display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;margin:0;position:relative;text-decoration:none;width:auto;font-family:sans-serif;font-size:1.6rem;line-height:1.3;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:8px;-webkit-transition:.25s ease,color .25s ease,border-color .25s ease;transition:.25s ease,color .25s ease,border-color .25s ease;background-color:transparent;background-image:none}.c-button,.c-button:visited{color:#069}.c-button,.c-button:hover{border:1px solid #069}.c-button:focus{border:1px solid #069}.c-button:focus,.c-button:hover{color:#fff;background-color:#069;background-image:none}.c-button:focus svg path,.c-button:hover svg path{fill:#fff}.c-button--small{font-size:1.4rem}.c-button--large{font-size:1.8rem;padding:16px}.c-button--primary{color:#fff;background-color:#069;background-image:none}.c-button--primary:visited{color:#fff}.c-button--primary,.c-button--primary:hover{border:1px solid #069}.c-button--primary:focus{border:1px solid #069}.c-button--primary:focus,.c-button--primary:hover{color:#069;background-color:#fff;background-image:none}.c-button--primary:focus svg path,.c-button--primary:hover svg path,.js .app-header__menu .app-header__link--dropdown:focus svg,.js .app-header__menu .app-header__link--dropdown:hover svg{fill:#069}.c-button--full-width{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;width:100%}.c-button--icon-left svg{margin-right:8px}.c-button--icon-right svg{margin-left:8px}.c-button--disabled,.c-button:disabled{color:#222;background-color:transparent;background-image:none;border:1px solid #eee;opacity:.7;cursor:default}.c-button--disabled:visited,.c-button:disabled:visited{color:#222}.c-button--disabled:hover,.c-button:disabled:hover{border:1px solid #eee;text-decoration:none}.c-button--disabled:focus,.c-button:disabled:focus{border:1px solid #eee;text-decoration:none}.c-button--disabled:focus,.c-button--disabled:hover,.c-button:disabled:focus,.c-button:disabled:hover{color:#222;background-color:transparent;background-image:none}.c-button--disabled:focus svg path,.c-button--disabled:hover svg path,.c-button:disabled:focus svg path,.c-button:disabled:hover svg path{fill:#222}.c-breadcrumbs{list-style:none;margin:0;padding:0}.c-breadcrumbs__link{color:inherit;display:inline-block;white-space:nowrap}.c-breadcrumbs__link>*,.c-footer a{vertical-align:middle}.c-breadcrumbs__link>svg{margin-left:4px}.c-footer{background-color:#2f2f2f;color:#d5d5d5;line-height:1.4;padding:24px 0;font-size:1.4rem}.c-breadcrumbs__link.hover,.c-breadcrumbs__link.visited,.c-breadcrumbs__link:hover,.c-breadcrumbs__link:visited,.c-footer a,.c-footer a.hover,.c-footer a.visited,.c-footer a:hover,.c-footer a:visited{color:inherit}.c-footer__header{margin-bottom:24px;padding-bottom:24px;border-bottom:1px solid #555}@media only screen and (min-width:768px){.c-footer__header{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}}@media only screen and (max-width:767px){.c-footer__header>:not(:last-child){margin-bottom:16px}}@media only screen and (min-width:768px){.c-footer__logo{-webkit-box-flex:1;-webkit-flex:1;-ms-flex:1;flex:1}}.c-footer__list,.c-footer__list--inline{list-style:none;margin:0;padding:0}.c-footer__list--inline .c-footer__item{margin:0 8px 0 0}.c-footer__list--inline .c-footer__item:last-child{margin-right:0}.c-footer__grid{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap}@supports (display:grid){.c-footer__grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));grid-column-gap:16px;grid-row-gap:32px}}.c-footer__group{-webkit-box-flex:1;-webkit-flex:1 1 50%;-ms-flex:1 1 50%;flex:1 1 50%;max-width:50%;padding-right:16px;margin-bottom:16px}@media only screen and (min-width:1024px){.c-footer__group{-webkit-flex-basis:25%;-ms-flex-preferred-size:25%;flex-basis:25%;max-width:25%}}@supports (display:grid){.c-footer__group{padding-right:0;max-width:none;margin-bottom:0}}.c-footer__heading{color:#eee;margin-bottom:16px;font-weight:700}.c-footer__item:not(:last-child){margin-bottom:4px}.c-form-field{margin-bottom:16px}.c-form-field__input{padding:.6em 1em;width:100%}.c-header{border-bottom:5px solid #000;padding:4px 0}@media only screen and (min-width:768px){.c-header{padding:16px 0}}.c-header__logo{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;max-width:112px}@media only screen and (min-width:768px){.c-header__logo{max-width:none}}.c-header__logo>img{height:auto}.c-header__container,.c-header__menu{margin:0 auto;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}.c-header__menu{list-style:none;padding:0;float:right;margin:0 0 0 auto;font-size:1.3rem;line-height:1.2}@media only screen and (min-width:768px){.c-header__menu{font-size:1.5rem}}.c-header__item{display:inline;vertical-align:middle;font-weight:700;color:#000;margin-left:16px}@media only screen and (min-width:768px){.c-header__item{margin-left:32px}}.c-header__link,.c-header__link--button{-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex}.c-header__link{white-space:nowrap;color:inherit}.c-header__link.hover,.c-header__link.visited,.c-header__link:hover,.c-header__link:visited{color:inherit}.c-header__link>svg{margin-left:8px}.c-header__link--button{cursor:pointer;margin:0;position:relative;text-decoration:none;width:auto;font-family:sans-serif;font-size:1.6rem;line-height:1.3;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;-webkit-transition:.25s ease,color .25s ease,border-color .25s ease;transition:.25s ease,color .25s ease,border-color .25s ease;color:#069;background-color:transparent;background-image:none;border:1px solid #069;display:inline-block;padding:4px 8px}.c-header__link--button:visited{color:#069}.c-header__link--button:hover{border:1px solid #069}.c-header__link--button:focus{border:1px solid #069}.c-header__link--button:focus,.c-header__link--button:hover{color:#fff;background-color:#069;background-image:none}.c-header__link--button:focus svg path,.c-header__link--button:hover svg path,.c-header__menu-button:focus svg path,.c-header__menu-button:hover svg path{fill:#fff}.c-header__link--button>*{vertical-align:middle}.c-header__menu-button{-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;cursor:pointer;display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex;position:relative;text-decoration:none;width:auto;font-family:sans-serif;font-size:1.6rem;line-height:1.3;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;-webkit-transition:.25s ease,color .25s ease,border-color .25s ease;transition:.25s ease,color .25s ease,border-color .25s ease;background-color:transparent;background-image:none;border:1px solid #069;border-color:#000;color:#000;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;padding:4px 8px;margin:0 16px 0 0}.c-header__menu-button:visited{color:#069}.c-header__menu-button:hover{border:1px solid #069}.c-header__menu-button:focus{border:1px solid #069}.c-header__menu-button:focus,.c-header__menu-button:hover{color:#fff;background-color:#069;background-image:none}.c-header__menu-button>*{vertical-align:middle}.c-header__menu-button>svg{margin:2px 0 0 2px;-webkit-transition:-webkit-transform .25s ease-in-out;transition:transform .25s ease-in-out;transition:transform .25s ease-in-out,-webkit-transform .25s ease-in-out}.c-header__menu-button:hover{color:#fff;background-color:#000;border-color:#000}.c-header__menu-button.is-open>svg{-webkit-transform:rotate(180deg);transform:rotate(180deg)}@media only screen and (max-width:767px){.c-header__hide-md-max{border:0;clip:rect(0,0,0,0);height:1px;margin:-100%;overflow:hidden;padding:0;position:absolute!important;width:1px}}.c-header__link--button.is-open>svg{-webkit-transform:rotate(-180deg);transform:rotate(-180deg)}.app-header{border-bottom:5px solid #000;font-size:1.6rem}.app-header__border-bottom{border-bottom:1px solid #eee;margin-bottom:8px;position:relative}.app-header__row{-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between}.app-header__right,.app-header__row{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}.app-header__brand{display:none}@media only screen and (min-width:768px){.app-header__brand{display:block;color:inherit;margin:0}}.app-header__site-links{border-left:1px solid #eee;-webkit-box-flex:0;-webkit-flex:0 0 auto;-ms-flex:0 0 auto;flex:0 0 auto;margin-bottom:0;margin-left:16px;text-align:right;padding:16px 0;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}.app-header__site-links>a{margin-left:16px}.app-header__container{margin:0 auto;max-width:1280px;padding:0 16px}.app-header__item,.app-header__menu{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex}.app-header__menu{list-style:none;padding:0;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap;-webkit-box-flex:1;-webkit-flex:1 1 100%;-ms-flex:1 1 100%;flex:1 1 100%;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;line-height:1.2;margin:0 0 8px -8px}.app-header__item{font-weight:700;margin-right:16px;position:relative}.app-header__item:last-child{margin-right:0}@media only screen and (min-width:540px){.app-header__item--pipe{white-space:nowrap}.app-header__item--pipe:before{content:"";border-left:2px solid #eee;padding-top:2px;padding-left:16px;padding-bottom:2px}}.app-header__link{color:inherit;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;white-space:nowrap}.app-header-tray a.hover,.app-header-tray a.visited,.app-header-tray a:hover,.app-header-tray a:visited,.app-header__link.hover,.app-header__link.visited,.app-header__link:hover,.app-header__link:visited,.c-sn-footer a,.c-sn-footer a.hover,.c-sn-footer a.visited,.c-sn-footer a:hover,.c-sn-footer a:visited{color:inherit}.app-header__link>svg{margin-left:4px;-webkit-transition-duration:.2s;transition-duration:.2s}.app-header__show-text{display:none}@media only screen and (min-width:540px){.app-header__show-text{display:inline}}.app-header__menu .app-header__link{padding:8px}.js .app-header__menu .app-header__link--dropdown:focus,.js .app-header__menu .app-header__link--dropdown:hover{color:#069;background-color:#eee;border-radius:2px;text-decoration:none}.js .app-header__menu .app-header__link.is-open{color:#069;background-color:#eee;border-radius:2px;text-decoration:none}.js .app-header__menu .app-header__link.is-open svg{fill:#069}.js .app-header__menu .app-header__link.is-open>svg{-webkit-transform:rotate(180deg);transform:rotate(180deg)}.c-meta{line-height:1.4;font-size:1.2rem;overflow:hidden}.c-meta__item{float:left}.c-meta__item:not(:last-child){padding-right:5px;margin-right:5px;border-right:1px solid #bbb}.c-meta__type{text-transform:uppercase;font-weight:700}.c-signpost-header{padding:4px 0;overflow:hidden;border-bottom:1px solid #d5d5d5;font-size:1.4rem}.c-signpost-header p{margin-bottom:0}@media only screen and (max-width:767px){.c-signpost-header{display:none}}.c-signpost-header__container{margin:0 auto}.c-signpost-header__left{float:left}.c-signpost-header__right{float:right}.c-skip-link{border:0;clip:rect(0,0,0,0);height:1px;margin:-100%;overflow:hidden;padding:0;position:absolute!important;width:1px;background-color:#069;color:#fff;text-align:center;font-size:1.4rem;z-index:9999}.c-skip-link:focus{border:0;clip:initial;height:auto;margin:0;overflow:auto;position:absolute;width:100%;padding:8px}.c-sn-footer{background-color:#222;color:#eee;padding:16px 0;font-size:1.3rem;line-height:1.4}.c-sn-footer__logo{margin-bottom:12px}.c-sn-footer__menu{list-style:none;padding:0;margin:0 0 8px}.c-sn-footer__item{display:inline-block;margin:0 8px 0 0}.c-sn-footer__copyright{color:#a2a2a2;margin:0}.hide{display:none}.container-type-banner-advert,.leaderboard-container,.leaderboard-or-billboard-container{display:none;font-size:0}@media only screen and (min-width:768px){.container-type-banner-advert,.leaderboard-container,.leaderboard-or-billboard-container{display:block;padding:8px 0}}.leaderboard-container,.leaderboard-or-billboard-container{background-color:#44444e;text-align:center}.leaderboard-or-billboard-inner{display:inline-block;min-width:728px;max-width:100%;position:relative;min-height:90px;line-height:0;word-spacing:0}.ad-with-label::after,.ad-with-label::before{content:'Advertisement';color:#fff;background:#999;font-size:9px;line-height:13px;font-family:arial,sans-serif;text-transform:uppercase;position:absolute;word-spacing:0;max-height:100%;top:0;bottom:0}.ad-with-label::before{border-right:1px solid #fff;left:-15px;-webkit-writing-mode:vertical-rl;-ms-writing-mode:tb-rl;writing-mode:vertical-rl}.ad-with-label::after{border-left:1px solid #fff;right:-14px;-webkit-writing-mode:vertical-lr;-ms-writing-mode:tb-lr;writing-mode:vertical-lr}.app-header-tray{font-size:1.8rem;background-color:#000;color:#eee;padding:32px 0}.app-header-tray a{color:inherit;font-size:1.4rem}.app-header-tray__container{margin:0 auto}.app-header-tray__keyline{border-bottom:1px solid #b3b3b3;padding-bottom:16px;margin-bottom:16px;border-color:#555}.app-header-tray__heading{display:inline-block;line-height:1.3;font-size:2rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;font-weight:400}@media only screen and (min-width:768px){.app-header-tray__search{max-width:600px}}.app-header-tray.has-tethered{position:absolute;width:100%;top:100%;-webkit-transform:translateY(5px);transform:translateY(5px);z-index:1;-webkit-box-shadow:0 8px 6px -6px rgba(0,0,0,.3);box-shadow:0 8px 6px -6px rgba(0,0,0,.3);left:0}.app-header-tray--reset.has-tethered{text-align:left;-webkit-transform:none;transform:none}.app-header-tray .c-button{border-color:#fff;color:#fff;background-color:transparent}.app-header-tray .c-button:hover{background-color:#fff;color:#000}.app-header-expander{background-color:#000;color:#eee;padding:24px 0 0}.app-header-expander__container{margin:0 auto;max-width:1280px;padding:0 16px}.app-header-expander__keyline{border-bottom:1px solid #b3b3b3;padding-bottom:16px;border-color:#555;margin-bottom:0}.app-header-expander__heading{font-size:2rem;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif;line-height:1.3}.app-header-expander__list{padding:0;margin:0}.app-header-expander__item{display:inline-block;margin-right:16px;margin-bottom:16px}.app-header-expander__item:last-child{margin-bottom:0}.app-header-expander__item--keyline{border-left:1px solid #fff;padding-left:16px}.app-header-expander__link{color:inherit;font-size:1.4rem;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center;white-space:nowrap}.app-header-expander__link.hover,.app-header-expander__link.visited,.app-header-expander__link:hover,.app-header-expander__link:visited{color:inherit}.app-header-expander__link>svg{margin-left:8px}.has-tethered .app-header-expander__heading{display:none}.app-header-expander.has-tethered{position:absolute;top:100%;-webkit-transform:translateY(8px);transform:translateY(8px);z-index:1;left:0;text-align:left;width:120%;min-width:-webkit-max-content;min-width:-moz-max-content;min-width:max-content;border-radius:0 0 2px 2px}.app-header-expander.has-tethered .app-header-expander__item{display:block;margin-right:0}.app-header-expander.has-tethered .app-header-expander__item--keyline{border-top:1px solid #fff;border-left:none;padding-top:16px;padding-left:0}.app-header-expander.has-tethered .app-header-expander__keyline{border:0;margin:0;padding-top:0}.app-mega-menu{line-height:1.4}.app-mega-menu__section{padding:16px 0}@media only screen and (min-width:1024px){.app-mega-menu__section{padding:24px 0}}.app-mega-menu__section:not(:last-child){border-bottom:1px solid #6f6f6f}.app-mega-menu__section-title{color:#fff;margin-bottom:16px;font-size:2.4rem}@media only screen and (min-width:768px){.app-mega-menu__heading{float:left;width:25%}}@media only screen and (min-width:320px){.app-mega-menu__content{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap}}@media only screen and (min-width:768px){.app-mega-menu__content{overflow:hidden;padding:3px}}@media only screen and (min-width:320px){.app-mega-menu__block{-webkit-box-flex:1;-webkit-flex:1 1 0;-ms-flex:1 1 0;flex:1 1 0;min-width:170px;margin-bottom:16px}}@media only screen and (min-width:1024px){.app-mega-menu__block{margin-bottom:0}}.app-mega-menu__list{list-style:none;margin:0;padding:0}.app-mega-menu__item{margin-bottom:4px}.app-mega-menu__link,.app-mega-menu__link.hover,.app-mega-menu__link.visited,.app-mega-menu__link:hover,.app-mega-menu__link:visited{color:inherit}.u-container{margin:0 auto;max-width:1280px;padding:0 16px}.u-color-open-access{color:#b74616}.u-color-inherit{color:inherit}.u-display-block{display:block}.u-display-inline{display:inline}.u-display-inline-block{display:inline-block}.u-display-flex{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;width:100%}.u-display-inline-flex{display:-webkit-inline-box;display:-webkit-inline-flex;display:-ms-inline-flexbox;display:inline-flex}.u-display-grid{display:grid}.u-display-table{display:table}.u-flex-direction-column,.u-flex-direction-row{-webkit-box-orient:horizontal;-webkit-box-direction:normal;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row}.u-flex-direction-column{-webkit-box-orient:vertical;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column}.u-flex-wrap{-webkit-flex-wrap:wrap;-ms-flex-wrap:wrap;flex-wrap:wrap}.u-align-items-center{-webkit-box-align:center;-webkit-align-items:center;-ms-flex-align:center;align-items:center}.u-align-items-baseline{-webkit-box-align:baseline;-webkit-align-items:baseline;-ms-flex-align:baseline;align-items:baseline}.u-justify-content-space-between{-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between}.u-justify-content-center{-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center}.u-justify-content-left{-webkit-box-pack:left;-webkit-justify-content:left;-ms-flex-pack:left;justify-content:left}.u-flex-grow{-webkit-box-flex:1;-webkit-flex:1 0 auto;-ms-flex:1 0 auto;flex:1 0 auto}.u-flex-grow-shrink{-webkit-box-flex:1;-webkit-flex:1 1 auto;-ms-flex:1 1 auto;flex:1 1 auto}.u-flex-shrink,.u-flex-static{-webkit-box-flex:0;-webkit-flex:0 1 auto;-ms-flex:0 1 auto;flex:0 1 auto}.u-flex-static{-webkit-flex:0 0 auto;-ms-flex:0 0 auto;flex:0 0 auto}.u-align-self-center{-webkit-align-self:center;-ms-flex-item-align:center;align-self:center}.u-align-self-start{-webkit-align-self:flex-start;-ms-flex-item-align:start;align-self:flex-start}.u-align-self-end{-webkit-align-self:flex-end;-ms-flex-item-align:end;align-self:flex-end}.u-position-absolute{position:absolute}.u-position-relative{position:relative}.u-position-top{top:0}.u-position-left{left:0}.u-position-bottom{bottom:0}.u-position-right{right:0}.u-position-negative-right{right:100%}@media only screen and (max-width:539px){.u-hide-sm-max{display:none;visibility:hidden}}.u-ma-0{margin:0}.u-ma-2{margin:2px}.u-ma-4{margin:4px}.u-ma-8{margin:8px}.u-ma-16{margin:16px}.u-ma-24{margin:24px}.u-ma-32{margin:32px}.u-ma-48{margin:48px}.u-ma-64{margin:64px}.u-ma-auto{margin:auto}.u-mt-0{margin-top:0}.u-mt-2{margin-top:2px}.u-mt-4{margin-top:4px}.u-mt-8{margin-top:8px}.u-mt-16{margin-top:16px}.u-mt-24{margin-top:24px}.u-mt-32{margin-top:32px}.u-mt-48{margin-top:48px}.u-mt-64{margin-top:64px}.u-mt-auto{margin-top:auto}.u-mr-0{margin-right:0}.u-mr-2{margin-right:2px}.u-mr-4{margin-right:4px}.u-mr-8{margin-right:8px}.u-mr-16{margin-right:16px}.u-mr-24{margin-right:24px}.u-mr-32{margin-right:32px}.u-mr-48{margin-right:48px}.u-mr-64{margin-right:64px}.u-mr-auto{margin-right:auto}.u-mb-0{margin-bottom:0}.u-mb-2{margin-bottom:2px}.u-mb-4{margin-bottom:4px}.u-mb-8{margin-bottom:8px}.u-mb-16{margin-bottom:16px}.u-mb-24{margin-bottom:24px}.u-mb-32{margin-bottom:32px}.u-mb-48{margin-bottom:48px}.u-mb-64{margin-bottom:64px}.u-mb-auto{margin-bottom:auto}.u-ml-0{margin-left:0}.u-ml-2{margin-left:2px}.u-ml-4{margin-left:4px}.u-ml-8{margin-left:8px}.u-ml-16{margin-left:16px}.u-ml-24{margin-left:24px}.u-ml-32{margin-left:32px}.u-ml-48{margin-left:48px}.u-ml-64{margin-left:64px}.u-ml-auto{margin-left:auto}.u-pa-0{padding:0}.u-pa-2{padding:2px}.u-pa-4{padding:4px}.u-pa-8{padding:8px}.u-pa-16{padding:16px}.u-pa-24{padding:24px}.u-pa-32{padding:32px}.u-pa-48{padding:48px}.u-pa-64{padding:64px}.u-pt-0{padding-top:0}.u-pt-2{padding-top:2px}.u-pt-4{padding-top:4px}.u-pt-8{padding-top:8px}.u-pt-16{padding-top:16px}.u-pt-24{padding-top:24px}.u-pt-32{padding-top:32px}.u-pt-48{padding-top:48px}.u-pt-64{padding-top:64px}.u-pr-0{padding-right:0}.u-pr-2{padding-right:2px}.u-pr-4{padding-right:4px}.u-pr-8{padding-right:8px}.u-pr-16{padding-right:16px}.u-pr-24{padding-right:24px}.u-pr-32{padding-right:32px}.u-pr-48{padding-right:48px}.u-pr-64{padding-right:64px}.u-pb-0{padding-bottom:0}.u-pb-2{padding-bottom:2px}.u-pb-4{padding-bottom:4px}.u-pb-8{padding-bottom:8px}.u-pb-16{padding-bottom:16px}.u-pb-24{padding-bottom:24px}.u-pb-32{padding-bottom:32px}.u-pb-48{padding-bottom:48px}.u-pb-64{padding-bottom:64px}.u-pl-0{padding-left:0}.u-pl-2{padding-left:2px}.u-pl-4{padding-left:4px}.u-pl-8{padding-left:8px}.u-pl-16{padding-left:16px}.u-pl-24{padding-left:24px}.u-pl-32{padding-left:32px}.u-pl-48{padding-left:48px}.u-pl-64{padding-left:64px}.c-header,.c-signpost-header{-webkit-box-sizing:border-box;box-sizing:border-box}.c-header *,.c-header ::after,.c-header ::before,.c-signpost-header *,.c-signpost-header ::after,.c-signpost-header ::before{-webkit-box-sizing:inherit;box-sizing:inherit}.c-header{margin-bottom:20px}.app-header-tray__container,.c-header__container,.c-signpost-header__container{max-width:1040px;padding:0 20px}.h1,.h2,.h3,.h4,.h5,.h6,h1,h2,h3,h4,h5,h6{font-weight:700}