@import url("/typography.css");
:root{color:#202925;background:#eef4f1;font-family:"IBM Plex Sans SC","PingFang SC","Microsoft YaHei",sans-serif;font-synthesis:none}*{box-sizing:border-box}body{margin:0}a{color:#285c53;text-underline-offset:5px}a:hover{color:#1f4942}a:focus-visible{outline:3px solid #7d5358;outline-offset:5px}::selection{background:#d9ebe7;color:#1f4942}.masthead,main,footer{width:min(100% - 48px,1080px);margin-inline:auto}.masthead{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:28px 0;border-bottom:1px solid #b8d8d1}.brand{font-size:23px;font-weight:600;text-decoration:none}.masthead nav{display:flex;gap:22px;flex-wrap:wrap}.masthead nav a{min-height:44px;display:inline-flex;align-items:center}main{padding:60px 0 72px}.breadcrumb{font-size:14px;color:#5f6d68}article{max-width:760px}h1{font-size:clamp(34px,5vw,56px);line-height:1.25;letter-spacing:-.025em;text-wrap:balance;margin:30px 0 24px}h2{font-size:26px;line-height:1.4;margin:0 0 18px}p,li,dd{font-size:17px;line-height:1.9}p{margin:12px 0}.lead{font-size:22px;line-height:1.7;color:#285c53}section{margin-top:52px}li{padding-left:5px;margin:12px 0}ul,ol{padding-left:25px}figure{margin:30px 0;background:#fbfcfa;padding:24px;border-radius:16px}img{display:block;width:100%;height:auto;max-height:360px;object-fit:contain}figcaption{color:#5f6d68;line-height:1.7;font-size:14px;margin-top:20px}dt{font-weight:600;margin-top:22px}dd{margin:6px 0 0}.action{border-top:1px solid #b8d8d1;padding-top:30px;margin-top:54px}.button{display:inline-flex;align-items:center;justify-content:center;min-height:52px;padding:12px 24px;border-radius:15px;background:#285c53;color:#fbfcfa;text-decoration:none}.button:hover{background:#1f4942;color:#fff}footer{border-top:1px solid #b8d8d1;padding:26px 0 40px;display:flex;gap:16px;flex-wrap:wrap;font-size:14px}.skip{position:absolute;top:-100px;left:24px;background:#fbfcfa;padding:12px}.skip:focus{top:12px}@media(max-width:600px){.masthead,main,footer{width:calc(100% - 36px)}.masthead{align-items:flex-start;flex-direction:column;gap:12px}.masthead nav{gap:8px 20px}main{padding-top:30px}h2{font-size:23px}.lead{font-size:20px}section{margin-top:38px}}@media print{.masthead,.action,footer,.skip{display:none}body{background:white}main{width:100%;padding:0}article{max-width:none}}

/* Reading extensions: practical guides, source notes and downloadable worksheets. */
.article-meta,.editorial-note{font-size:14px;line-height:1.8;color:#5f6d68}.article-toc{margin:32px 0;padding:24px 0;border-block:1px solid #b8d8d1}.article-toc ol{margin-bottom:0}.article-toc li{font-size:15px;margin:9px 0}.download{margin:24px 0;font-size:15px}.download a{font-weight:600}.guide-list section{padding:30px 0;border-top:1px solid #b8d8d1;margin:0}.guide-list{margin-top:40px}.guide-list h2{margin:8px 0 14px}.guide-list section>p:first-child{color:#5f6d68;font-size:15px}.related{border-top:1px solid #b8d8d1;padding-top:32px}section[id]{scroll-margin-top:24px}@media print{.article-toc,.download,.related{display:none}}