.usa-search .ncbi-autocomplete{display:block;float:left;width:calc(100% - 4.5rem);max-width:46rem}@media screen and (min-width:481px){.usa-search .ncbi-autocomplete{width:calc(100% - 8.5rem)}}.usa-search .ncbi-autocomplete .tt-suggestion{height:3.3rem;padding:0.65rem 1rem;font-size:1.4rem}.usa-search .ncbi-autocomplete [type=search],.usa-search .ncbi-autocomplete .usa-search-input{width:100%}@media screen and (min-width:481px){.usa-search-big .ncbi-autocomplete{width:calc(100% - 11.6rem)}.usa-search-big .ncbi-autocomplete .tt-suggestion{height:4.4rem;padding:1.2rem 1rem;font-size:1.7rem}}@media screen and (min-width:481px){.usa-search-small .ncbi-autocomplete{width:calc(100% - 4.5rem)}}.ncbi-autocomplete{position:relative;display:inline-block}.ncbi-autocomplete .tt-menu{background-color:#fff;border:1px solid rgba(0,0,0,0.15);box-shadow:0 3px 1.4rem -0.4rem rgba(0,0,0,0.3);width:100%;box-sizing:border-box;border-top:none}.ncbi-autocomplete .tt-menu .tt-suggestion{height:4.4rem;line-height:2rem;padding:1.2rem 1rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;cursor:pointer}.ncbi-autocomplete .tt-menu .tt-suggestion.tt-cursor{background-color:#e1f3f8}.usa-search .ncbi-autocomplete{display:block;float:left;width:calc(100% - 11.6rem);max-width:none}.usa-search .ncbi-autocomplete input[type=search]{width:100%!important}.usa-search .ncbi-autocomplete .tt-menu{width:auto;right:0}@media screen and (max-width:759px){.usa-search .ncbi-autocomplete{width:calc(100% - 4.4rem)}.usa-search .ncbi-autocomplete .tt-menu{right:-4.4rem;box-shadow:0 0 2.5rem rgba(0,0,0,0.3)}}.search-form{background-color:#f1f1f1}.search-form>.inner-wrap{width:1020px;margin:0 auto}@media screen and (min-width:1020px){.search-form>.inner-wrap::after{content:'';display:block;clear:both;height:0}}@media screen and (max-width:1019px){.search-form>.inner-wrap{width:760px}}@media screen and (max-width:759px){.search-form>.inner-wrap{width:auto;margin:0}}@media screen and (min-width:1020px){.search-form>.inner-wrap{padding:30px 0 20px}}@media screen and (max-width:1019px){.search-form>.inner-wrap{padding:2rem 2rem 3rem}}.search-form .back-to-search{display:none}.search-form .pubmed-logo{display:block;width:18rem;height:5rem}.search-form .pubmed-logo:focus{outline:0.2rem dotted #AEB0B5;outline-offset:.3rem}@media screen and (min-width:1020px){.search-form .pubmed-logo{margin:-0.5rem 6rem 0 2rem;float:left}}@media screen and (max-width:1019px){.search-form .pubmed-logo{width:16.5rem;height:4.5rem;margin:0 auto}}@media screen and (max-width:376px){.search-form .pubmed-logo{width:14rem;height:4rem}}.search-form .pubmed-logo:focus{outline:0.2rem dotted #AEB0B5;outline-offset:.3rem}@media screen and (min-width:1020px){.search-form .search-input{float:left;width:760px;padding:0 2rem}}@media screen and (max-width:1019px){.search-form .search-input{margin-top:1.3rem}}.search-form .search-input .form-field{margin-left:0}.search-form .search-input input[type="search"]{display:inline-block;max-width:none;border-color:#aeb0b5;background-color:#ffffff;padding-right:5rem;transition:box-shadow 0.15s}.search-form .search-input input[type="search"]:focus{box-shadow:0 0 3px #CCC,0 0 7px #CCC;outline:none}@media screen and (max-width:759px){.search-form .search-input input[type="search"]{width:calc(100% - 4.4rem);font-size:1.6rem;height:4.4rem;padding-left:1rem}.search-form .search-input .search-btn{width:4.4rem;height:4.4rem;background-image:url("data:image/svg+xml;base64,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");background-size:2.4rem}.search-form .search-input .search-btn .usa-search-submit-text{display:none}}.search-form .search-input .search-btn{display:inline-block;vertical-align:top;position:relative;transition:background-color 0.15s;font-size:1.87rem}.search-form .search-input .clear-btn{display:none;width:4rem;height:3.6rem;position:absolute;margin-left:-4.25rem;margin-top:0.4rem;background:rgba(255,255,255,0.9) url("data:image/svg+xml;base64,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") no-repeat center/2rem;box-shadow:-0.4rem 0 0.6rem -0.3rem rgba(0,0,0,0.1)}.search-form .search-input .clear-btn.active{display:inline-block}.search-form .search-input .clear-btn:focus{outline:0.2rem dotted #AEB0B5;outline-offset:.3rem;outline-offset:-0.7rem}.search-form .search-input-trigger{display:none}.search-form .search-links-wrapper{display:flex;flex-direction:row;justify-content:space-between;align-items:baseline}@media screen and (min-width:1020px){.search-form .search-links-wrapper{float:left;width:760px;padding:0 2rem}}.search-form .search-links-wrapper .search-links{font-size:1.4rem;display:inline-block;clear:left}@media screen and (max-width:1019px){.search-form .search-links-wrapper .search-links{margin-left:0;padding-left:0}}.search-form .search-links-wrapper .search-links .search-input-link{color:#0071bc;margin-top:.5rem;margin-right:1rem;display:inline-block}.search-form .search-links-wrapper .search-links .search-input-link.hidden{display:none}.search-form .search-links-wrapper .user-guide-link{font-size:1.4rem;display:inline-block;margin-left:0.25rem}.search-form .search-links-wrapper .user-guide-link>a:active,.search-form .search-links-wrapper .user-guide-link>a:visited{color:#0071bc}.search-form.content-page-layout{border-bottom:1px solid rgba(0,0,0,0.1)}@media screen and (max-width:376px){.search-form.content-page-layout.search-form .pubmed-logo{margin:.5rem auto}}@media screen and (max-width:759px){.search-form.content-page-layout>.inner-wrap{padding-bottom:1rem;padding-top:1rem}}.search-form.content-page-layout .search-input input [type="search"]{background-color:#ffffff}@media screen and (max-width:759px){.search-form.content-page-layout .search-input{display:none}.search-form.content-page-layout .search-input.active{display:block}}@media screen and (max-width:759px){.search-form.content-page-layout .search-links-wrapper{justify-content:center;padding-top:.5rem}.search-form.content-page-layout .search-links-wrapper .search-links{margin-left:-3px;padding-right:0}.search-form.content-page-layout .search-links-wrapper .search-links .search-input-link{margin-right:.7rem}}.search-form.content-page-layout .back-to-search{display:none;position:absolute;left:.8rem;top:2rem;width:4.4rem;height:4.4rem;background:url("data:image/svg+xml;base64,PHN2ZyB2ZXJzaW9uPSIxLjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgdmlld0JveD0iMCAwIDQ3Ny4xNzUgNDc3LjE3NSI+CjxnPgoJPHBhdGggZmlsbD0iIzQ5NDQ0MCIgZD0iTTE0NS4xODgsMjM4LjU3NWwyMTUuNS0yMTUuNWM1LjMtNS4zLDUuMy0xMy44LDAtMTkuMXMtMTMuOC01LjMtMTkuMSwwbC0yMjUuMSwyMjUuMWMtNS4zLDUuMy01LjMsMTMuOCwwLDE5LjFsMjI1LjEsMjI1IGMyLjYsMi42LDYuMSw0LDkuNSw0czYuOS0xLjMsOS41LTRjNS4zLTUuMyw1LjMtMTMuOCwwLTE5LjFMMTQ1LjE4OCwyMzguNTc1eiIvPgo8L2c+Cjwvc3ZnPgo=") no-repeat center/3.2rem}@media screen and (max-width:759px){.search-form.content-page-layout .back-to-search{display:inline-block}}.search-form.content-page-layout .search-input-trigger{display:none;position:absolute;right:1.2rem;top:2rem;width:4.4rem;height:4.4rem;background:url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAxMDAgMTA0IiB3aWR0aD0iMTAwcHgiIGhlaWdodD0iMTA0cHgiPgogIDxwYXRoIGZpbGw9IiM0OTQ0NDAiIGQ9Ik0gNDAuOTUxMTcyLC03LjUyNTU2MzJlLTQgQSA0MC45NDk5MTUsNDAuODE1NTYxIDAgMCAwIDAsNDAuODEzNjk3IDQwLjk0OTkxNSw0MC44MTU1NjEgMCAwIDAgNDAuOTUxMTcyLDgxLjYzMDEwNyA0MC45NDk5MTUsNDAuODE1NTYxIDAgMCAwIDY1LjIwODk4NCw3My42Mzk4NjcgTCA5NC44NjEzMywxMDMuNDg1NTggYyAyLjMxMjk5LDEuOTg3MiA2LjU4OTM0LC0yLjI1NTQxIDQuNjQ2NDgsLTQuNjkxNDEzIEwgNzAuMDg5ODQ0LDY5LjQ3MTg5NyBBIDQwLjk0OTkxNSw0MC44MTU1NjEgMCAwIDAgODEuOTAwMzkxLDQwLjgxMzY5NyA0MC45NDk5MTUsNDAuODE1NTYxIDAgMCAwIDQwLjk1MTE3MiwtNy41MjU1NjMyZS00IFogbSAwLDQuMzMzOTc5OTU2MzIgQSAzNi42MDA3MzYsMzYuNDgwNjUyIDAgMCAxIDc3LjU1MjczNCw0MC44MTM2OTcgMzYuNjAwNzM2LDM2LjQ4MDY1MiAwIDAgMSA0MC45NTExNzIsNzcuMjk0MTY3IDM2LjYwMDczNiwzNi40ODA2NTIgMCAwIDEgNC4zNDk2MDksNDAuODEzNjk3IDM2LjYwMDczNiwzNi40ODA2NTIgMCAwIDEgNDAuOTUxMTcyLDQuMzMzMjI3NCBaIi8+Cjwvc3ZnPgo=") no-repeat center/2.8rem;transition:background-size 0.3s}.search-form.content-page-layout .search-input-trigger::after{content:'';position:absolute;left:0;right:0;top:0;bottom:0;background:url("data:image/svg+xml;base64,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") no-repeat -0.3rem center/0;transition:background-size 0.3s}@media screen and (min-width:481px){.search-form.content-page-layout .search-input-trigger{right:2rem}.search-form.content-page-layout .search-input-trigger::after{background-position:center}}.search-form.content-page-layout .search-input-trigger.active{background-size:0}.search-form.content-page-layout .search-input-trigger.active::after{background-size:3.2rem}@media screen and (max-width:759px){.search-form.content-page-layout .search-input-trigger{display:block}}.content-page{width:1020px;margin:0 auto;min-height:40rem;padding-top:4rem;padding-bottom:6rem}@media screen and (min-width:1020px){.content-page::after{content:'';display:block;clear:both;height:0}}@media screen and (max-width:1019px){.content-page{width:760px}}@media screen and (max-width:759px){.content-page{width:auto;margin:0}}@media screen and (max-width:1019px){.content-page{padding-top:4rem;padding-bottom:5rem}}@media screen and (max-width:759px){.content-page{padding:4rem 2rem}}.content-page>.title{font-size:2.6rem;line-height:1.4;margin:0 0 1.9rem}.content-page h1,.content-page h2,.content-page h3{margin:2.4rem 0}.content-page h1{font-size:2.6rem;margin-bottom:1.9rem}.content-page h2{font-size:2.2rem;margin-bottom:2rem}.content-page h3{font-size:1.9rem;margin-bottom:2.1rem}.content-page code{padding:0 0.4rem;margin:-0.2rem 0;background-color:#f1f1f1;line-height:2.4rem;display:inline-block;font-size:0.95em}.content-page ul.narrow>li{margin:0}.content-page ul.dashes{list-style-type:none}.content-page ul.dashes>li::before{content:'\2013';position:absolute;margin-left:-1.6rem}.content-page ul.alpha{list-style-type:lower-alpha}.content-page .figure{margin:2.4rem 0}.content-page .figure img{vertical-align:top;box-shadow:0 0.5rem 4rem rgba(0,0,0,0.14)}@media print{.search-form,.content-page>.back-to-top{display:none}}