:root {
  --bg: #ffffff; --bg-alt: #f8fafc; --surface: #f1f5f9;
  --border: #e2e8f0; --border-light: #cbd5e1;
  --brand: #1461DC; --brand-light: #2563eb;
  --brand-bg: rgba(20,97,220,0.06);
  --text: #0f172a; --text-2: #334155; --muted: #64748b;
  --sidebar-w: 260px; --toc-w: 220px; --header-h: 56px;
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:calc(var(--header-h)+16px)}
body{font-family:"Inter",system-ui,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--brand-light);text-decoration:none}a:hover{text-decoration:underline}
code,.mono{font-family:"JetBrains Mono",monospace}
.header{position:fixed;top:0;left:0;right:0;z-index:100;height:var(--header-h);background:rgba(255,255,255,0.9);backdrop-filter:blur(12px);border-bottom:1px solid var(--border);display:flex;align-items:center;padding:0 20px;gap:16px}
.header-logo{display:flex;align-items:center;gap:8px;font-weight:700;font-size:16px;color:var(--text);flex-shrink:0}.header-logo picture{display:flex;align-items:center}
.header-logo img{height:30px}
@media(max-width:480px){.header-logo img{height:24px}}
.header-sep{width:1px;height:24px;background:var(--border);flex-shrink:0}
.header-title{font-size:14px;font-weight:500;color:var(--muted)}
.header-version{font-size:11px;font-weight:600;color:var(--brand);background:var(--brand-bg);padding:2px 8px;border-radius:4px;margin-left:4px;transition:opacity .15s}.header-version:hover{opacity:.8;text-decoration:none}
.header-links{margin-left:auto;display:flex;gap:12px}
.header-links a{font-size:13px;font-weight:500;color:var(--muted);padding:4px 10px;border-radius:5px;transition:color .15s,background .15s}
.header-links a:hover{color:var(--text);background:var(--surface);text-decoration:none}
.mobile-menu-btn{display:none;background:none;border:none;font-size:20px;cursor:pointer;color:var(--text);padding:4px}
.layout{display:grid;grid-template-columns:var(--sidebar-w) 1fr var(--toc-w);margin-top:var(--header-h);min-height:calc(100vh - var(--header-h))}
.sidebar{position:sticky;top:var(--header-h);height:calc(100vh - var(--header-h));overflow-y:auto;padding:16px 0;border-right:1px solid var(--border);background:var(--bg)}
.sidebar::-webkit-scrollbar{width:4px}.sidebar::-webkit-scrollbar-thumb{background:var(--border);border-radius:2px}
.nav-section{padding:10px 20px 4px;font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--muted)}
.nav-item{display:block;padding:6px 20px;font-size:13.5px;font-weight:450;color:var(--text-2);cursor:pointer;border-left:3px solid transparent;transition:background .1s,border-color .1s,color .1s}
.nav-item:hover{background:var(--brand-bg);color:var(--text);text-decoration:none}
.nav-item.active{color:var(--brand);border-left-color:var(--brand);background:var(--brand-bg);font-weight:600}
.nav-date{float:right;font-size:11px;color:var(--muted);font-weight:400}
.nav-divider{height:1px;background:var(--border);margin:8px 16px}
.content{padding:32px 48px 80px;max-width:100%;min-width:0;overflow:hidden}
.content h1{font-size:30px;font-weight:700;letter-spacing:-.02em;margin-bottom:8px;padding-bottom:12px;border-bottom:1px solid var(--border)}
.content h2{font-size:22px;font-weight:600;margin-top:36px;margin-bottom:12px;padding-bottom:6px;border-bottom:1px solid var(--border);letter-spacing:-.01em}
.content h3{font-size:17px;font-weight:600;margin-top:28px;margin-bottom:8px}
.content h4{font-size:15px;font-weight:600;margin-top:20px;margin-bottom:6px}
.content p{margin-bottom:12px;font-size:15px;color:var(--text-2)}
.content ul,.content ol{margin-bottom:12px;padding-left:24px;font-size:15px;color:var(--text-2)}
.content li{margin-bottom:4px}.content li>ul,.content li>ol{margin-top:4px;margin-bottom:4px}
.content blockquote{border-left:3px solid var(--brand);padding:8px 16px;margin-bottom:12px;background:var(--brand-bg);border-radius:0 6px 6px 0;font-size:14px;color:var(--text-2)}
.content blockquote p{margin-bottom:4px}
.content code{background:var(--surface);padding:2px 6px;border-radius:4px;font-size:13px;color:#c7254e}
.content pre{background:#1e293b;border:1px solid #334155;border-radius:8px;padding:16px;overflow-x:auto;margin-bottom:16px}
.content pre code{background:none;padding:0;color:#e2e8f0;font-size:13px;line-height:1.6}
.content table{width:100%;border-collapse:collapse;margin-bottom:16px;font-size:14px}
.content th,.content td{padding:8px 12px;text-align:left;border:1px solid var(--border)}
.content th{background:var(--surface);font-weight:600;font-size:13px}
.content td{color:var(--text-2)}
.content hr{border:none;border-top:1px solid var(--border);margin:24px 0}
.content a{color:var(--brand-light)}.content img{max-width:100%;border-radius:6px}.content strong{color:var(--text)}
.toc{position:sticky;top:var(--header-h);height:calc(100vh - var(--header-h));overflow-y:auto;padding:20px 16px;border-left:1px solid var(--border);background:var(--bg)}
.toc::-webkit-scrollbar{width:4px}.toc::-webkit-scrollbar-thumb{background:var(--border);border-radius:2px}
.toc-title{font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin-bottom:10px}
.toc-link{display:block;padding:3px 0;font-size:12.5px;color:var(--muted);transition:color .15s;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.toc-link:hover{color:var(--text);text-decoration:none}
.toc-link.depth-3{padding-left:12px;font-size:12px}
@media(max-width:1100px){.layout{grid-template-columns:var(--sidebar-w) 1fr}.toc{display:none}}
@media(max-width:768px){.mobile-menu-btn{display:block}.header-links{display:none}.layout{grid-template-columns:1fr}.sidebar{display:none;position:fixed;top:var(--header-h);left:0;width:280px;z-index:50;box-shadow:4px 0 12px rgba(0,0,0,.08)}.sidebar.open{display:block}.toc{display:none}.content{padding:24px 20px 60px}}