*,*::before,*::after{box-sizing:border-box}
body{margin:0;font-family:"PingFang SC","Microsoft YaHei",sans-serif;color:#1a1a1a;background:#fff;line-height:1.82}
img{display:block;max-width:100%;height:auto}
a{color:#047857;text-decoration:none}
a:hover{text-decoration:underline}
.shell{width:min(900px,calc(100% - 36px));margin:0 auto}

.site-head{position:sticky;top:0;z-index:90;background:#fff;border-bottom:1px solid #e5e7eb}
.head-row{display:flex;align-items:center;justify-content:space-between;min-height:64px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:16px;color:#111}
.brand img{width:38px;border-radius:10px}
.top-nav{display:flex;gap:16px;flex-wrap:wrap}
.top-nav a{color:#555;font-size:14px}
.menu-btn{display:none;border:1px solid #ddd;background:#fff;border-radius:8px;padding:8px 12px;cursor:pointer;font-size:14px}
.mnav{display:none;flex-direction:column;padding:12px 18px 16px;border-top:1px solid #eee;background:#fff}
.mnav.on{display:flex}
.mnav a{padding:10px 0;border-bottom:1px solid #f3f3f3;color:#444;font-size:14px}

.page-hero{padding:44px 0 20px;text-align:center}
.page-hero h1{font-size:clamp(26px,4.2vw,38px);line-height:1.28;margin:0 0 14px;color:#111}
.page-hero .deck{color:#555;font-size:16px;max-width:720px;margin:0 auto}

.toc-panel{margin:28px 0 40px;padding:24px 28px;border:2px solid #d1fae5;border-radius:16px;background:linear-gradient(180deg,#f0fdf4 0%,#fff 100%)}
.toc-panel h2{font-size:15px;margin:0 0 16px;color:#065f46;letter-spacing:.06em;text-transform:uppercase;font-weight:700}
.toc-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px 20px;list-style:none;margin:0;padding:0}
.toc-grid li{margin:0}
.toc-grid a{display:flex;align-items:baseline;gap:10px;padding:10px 14px;border-radius:10px;background:#fff;border:1px solid #e5e7eb;color:#374151;font-size:14px;transition:border-color .15s,background .15s}
.toc-grid a:hover{border-color:#6ee7b7;background:#ecfdf5;text-decoration:none;color:#047857}
.toc-num{font-family:Consolas,"Courier New",monospace;font-size:12px;font-weight:700;color:#059669;min-width:28px}

.section{padding:36px 0 44px;border-top:1px solid #f0f0f0;scroll-margin-top:80px}
.section:first-of-type{border-top:none;padding-top:8px}
.section h2{font-size:24px;margin:0 0 16px;color:#111;line-height:1.35}
.section h3{font-size:18px;margin:24px 0 10px;color:#222}
.section p,.section li{color:#444;font-size:15px;margin:0 0 14px}
.section ul,.section ol{padding-left:22px;margin:0 0 14px}
.section figure{margin:20px 0;border:1px solid #eee;border-radius:12px;overflow:hidden;background:#fafafa}
.section figcaption{padding:10px 14px;font-size:13px;color:#666;border-top:1px solid #eee;background:#fff}

.img-row{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:18px 0}
.img-row img{aspect-ratio:9/16;object-fit:cover;width:100%;border-radius:10px;border:1px solid #eee}

.callout{padding:16px 20px;border-radius:12px;background:#ecfdf5;border-left:4px solid #10b981;color:#065f46;font-size:14px;margin:18px 0}
.warn-box{padding:16px 20px;border-radius:12px;background:#fef2f2;border-left:4px solid #ef4444;color:#991b1b;font-size:14px;margin:18px 0}

.link-row{display:flex;flex-wrap:wrap;gap:10px;margin:20px 0}
.link-chip{display:inline-block;padding:8px 16px;border:1px solid #d1d5db;border-radius:999px;font-size:14px;color:#374151;background:#fafafa}
.link-chip:hover{background:#ecfdf5;border-color:#6ee7b7;color:#047857;text-decoration:none}

.faq{padding:36px 0 48px;border-top:1px solid #f0f0f0}
.faq h2{font-size:24px;margin:0 0 16px}
.faq details{border:1px solid #ececec;border-radius:10px;padding:14px 18px;margin-bottom:10px;background:#fafafa}
.faq summary{font-weight:600;cursor:pointer;color:#222}
.faq p{margin:10px 0 0;color:#555;font-size:14px}

.prose{padding:40px 0 56px}
.prose h1{font-size:28px;margin:0 0 16px}
.prose h2{font-size:20px;margin:28px 0 12px;color:#222}
.prose p,.prose li{color:#444;font-size:15px}
.related{margin-top:32px;padding:18px 20px;border:1px solid #e8e8e8;border-radius:12px;background:#f9fafb}
.related h3{margin:0 0 10px;font-size:16px}
.related a{display:block;padding:5px 0;color:#047857;font-size:14px}

.site-foot{padding:36px 0;background:#fafafa;border-top:1px solid #eee;font-size:13px;color:#888}
.site-foot a{color:#666;margin-right:14px}
.err{min-height:58vh;display:grid;place-items:center;text-align:center;padding:40px 16px}
.err h1{font-size:48px;margin:0 0 12px;color:#ccc}

@media(max-width:720px){
  .toc-grid{grid-template-columns:1fr}
  .img-row{grid-template-columns:1fr}
  .menu-btn{display:inline-flex}
  .top-nav{display:none}
}