:root{color-scheme:light;--ink:#242a32;--muted:#65707c;--line:#e3e7ec;--blue:#245fc2}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:22px}body{margin:0;background:#fff;color:var(--ink);font:16px/1.85 "PingFang SC","Microsoft YaHei",sans-serif}a{color:var(--blue);text-underline-offset:3px}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid #245fc2;outline-offset:4px}button{font:inherit;cursor:pointer}.site-header{max-width:1040px;margin:auto;padding:20px 24px;display:flex;gap:24px;align-items:center;border-bottom:1px solid var(--line)}.brand{color:var(--ink);font-size:22px;font-weight:700;text-decoration:none;letter-spacing:-.5px}.brand span{font-weight:400;color:var(--muted);font-size:16px;margin-left:7px}.site-header nav{margin-left:auto;display:flex;gap:22px;font-size:14px}.site-header nav a{color:var(--muted);text-decoration:none}.layout{max-width:1040px;margin:auto;padding:32px 24px 48px;display:grid;grid-template-columns:150px minmax(0,740px);gap:40px}.toc{font-size:13px;position:sticky;top:24px;align-self:start;padding-top:5px}.toc strong{font-size:14px;color:var(--ink)}.toc a{display:block;color:var(--muted);text-decoration:none;padding:5px 0}.toc a:hover{color:var(--blue)}article{min-width:0}.meta{font-size:12px;color:var(--muted);margin:0 0 12px}h1{font-size:30px;line-height:1.45;letter-spacing:-.7px;margin:0 0 14px;max-width:720px}h2{font-size:21px;line-height:1.5;margin:34px 0 13px}h3{font-size:16px;margin:20px 0 8px}p{margin:10px 0 15px}ol,ul{padding-left:23px;margin:10px 0 16px}li{margin:5px 0}.lead{color:#505b68;font-size:15px}.resources{display:flex;flex-wrap:wrap;gap:7px 20px;padding:12px 0;border-block:1px solid var(--line);font-size:14px}.resources a{white-space:nowrap}.video-wrap{margin:20px 0 12px;max-width:680px}video{width:100%;aspect-ratio:16/9;display:block;background:#0d1925;border-radius:5px}.chapters{display:flex;gap:7px;flex-wrap:wrap;margin:10px 0}.chapters button{font-size:12px;background:#f5f7fa;color:#40556c;border:1px solid var(--line);border-radius:4px;padding:4px 9px}.small{font-size:12px;color:var(--muted)}.note{font-size:14px;background:#f5f8fc;padding:11px 15px;border-left:3px solid #7a9ccc;margin:16px 0}.success{font-size:14px;color:#3a6149;margin-top:7px}figure{margin:17px 0 22px}figure a{display:block}figure img{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:4px}figcaption{font-size:12px;color:var(--muted);line-height:1.65;margin-top:6px}.extra{border-bottom:1px solid var(--line);padding:10px 0}.extra summary{font-size:14px;cursor:pointer;color:#40556c}.extra figure{margin-bottom:10px}code{font:13px/1.7 ui-monospace,SFMono-Regular,Menlo,monospace;overflow-wrap:anywhere;background:#f0f3f7;padding:2px 5px;border-radius:3px}pre{background:#f4f6f8;border:1px solid var(--line);padding:15px;max-width:100%;overflow:auto;font-size:12px;line-height:1.7;border-radius:4px}pre code{padding:0;background:none;white-space:pre;overflow-wrap:normal}.code-toolbar{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:10px 0;font-size:13px}.code-toolbar button{border:1px solid #b5c8e4;border-radius:4px;background:#fff;color:var(--blue);padding:5px 13px;font-size:13px}.code-details{border:1px solid var(--line);padding:12px 15px;border-radius:4px}.code-details>summary{cursor:pointer;font-size:14px;font-weight:600}.code-details pre{max-height:430px}.table-wrap{max-width:100%;overflow-x:auto}table{border-collapse:collapse;width:100%;font-size:13px;line-height:1.7;margin:15px 0}th,td{text-align:left;padding:10px 12px;border:1px solid var(--line);vertical-align:top}th{background:#f5f7fa;font-weight:600}td:first-child{min-width:100px}.footnotes{font-size:13px;color:var(--muted);border-top:1px solid var(--line);margin-top:30px;padding-top:18px}.footnotes ul{margin:8px 0}.site-footer{max-width:1040px;margin:auto;border-top:1px solid var(--line);padding:18px 24px;color:var(--muted);font-size:12px}#copy-status{min-height:22px;font-size:12px;color:#3a6149}
@media(max-width:800px){.layout{grid-template-columns:1fr;gap:22px;padding:24px 20px 40px;max-width:780px}.toc{position:static;border-bottom:1px solid var(--line);padding:0 0 14px}.toc strong{display:none}.toc a{display:inline-block;padding:3px 11px 3px 0}h1{font-size:26px}.site-header{padding:16px 20px}.site-header nav{gap:14px}.brand{font-size:21px}h2{font-size:20px}body{font-size:15px}.video-wrap{max-width:100%}}
@media(max-width:400px){.site-header{gap:10px}.site-header nav{gap:11px;font-size:12px}.brand span{font-size:13px}h1{font-size:24px}.layout{padding-inline:16px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

.opening-cover{margin:0 0 24px}.opening-cover img{border:0;border-radius:5px;aspect-ratio:16/9}