:root{--bg:#fff;--bg-card:#f8fafc;--bg-sidebar:#f1f5f9;--bg-hover:#e2e8f0;--bg-active:#dbeafe;--border:#e2e8f0;--border-light:#f1f5f9;--text:#1e293b;--text-muted:#475569;--text-dim:#94a3b8;--accent:#188bf6;--accent-hover:#0b6fcc;--accent-subtle:rgba(24,139,246,.08);--accent-green:#37ca37;--success:#22c55e;--warning:#eab308;--radius:8px;--shadow-sm:0 1px 2px rgba(0,0,0,.05);--shadow-md:0 4px 12px rgba(0,0,0,.08)}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased}.app-layout{display:flex;min-height:100vh}.sidebar{width:280px;background:var(--bg-sidebar);border-right:1px solid var(--border);display:flex;flex-direction:column;position:fixed;top:0;left:0;bottom:0;z-index:50;overflow-y:auto;transition:transform .3s ease}.sidebar-header{padding:20px 16px;border-bottom:1px solid var(--border);gap:12px}.sidebar-header,.sidebar-logo{display:flex;align-items:center}.sidebar-logo{width:36px;height:36px;background:linear-gradient(135deg,var(--accent),var(--accent-green));border-radius:8px;justify-content:center;font-weight:700;font-size:14px;color:#fff;flex-shrink:0}.sidebar-brand h1{font-size:14px;font-weight:700;color:var(--text);line-height:1.2}.sidebar-brand p{font-size:11px;color:var(--text-dim);margin-top:2px}.sidebar-search{padding:12px 16px}.sidebar-search input{width:100%;padding:8px 12px;background:var(--bg);border:1px solid var(--border);border-radius:var(--radius);color:var(--text);font-size:13px;outline:none;transition:border-color .2s,box-shadow .2s}.sidebar-search input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-subtle)}.sidebar-search input::placeholder{color:var(--text-dim)}.sidebar-nav{flex:1 1;padding:8px 0;overflow-y:auto}.nav-section{margin-bottom:2px}.nav-section-header{display:flex;align-items:center;gap:8px;padding:8px 16px;cursor:pointer;font-size:13px;font-weight:600;color:var(--text-muted);transition:color .2s,background .15s;-webkit-user-select:none;-moz-user-select:none;user-select:none;border:none;background:none;width:100%;text-align:left}.nav-section-header:hover{color:var(--text);background:var(--bg-hover)}.nav-section-header .icon{font-size:15px;width:20px;text-align:center}.nav-section-header .chevron{margin-left:auto;font-size:10px;transition:transform .2s;color:var(--text-dim)}.nav-section-header.open .chevron{transform:rotate(90deg)}.nav-section-header.active-section{color:var(--accent);background:var(--accent-subtle)}.nav-articles{display:none;padding:2px 0}.nav-articles.open{display:block}.nav-article-link{display:block;padding:6px 16px 6px 44px;font-size:13px;color:var(--text-dim);text-decoration:none;cursor:pointer;transition:all .15s;border-left:2px solid transparent}.nav-article-link:hover{color:var(--text);background:var(--bg-hover)}.nav-article-link.active{color:var(--accent);background:var(--accent-subtle);border-left-color:var(--accent);font-weight:500}.main-content{flex:1 1;margin-left:280px;min-height:100vh;background:var(--bg)}.content-header{padding:14px 32px;border-bottom:1px solid var(--border);justify-content:space-between;position:-webkit-sticky;position:sticky;top:0;background:hsla(0,0%,100%,.92);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);z-index:30}.breadcrumb,.content-header{display:flex;align-items:center}.breadcrumb{gap:8px;font-size:13px;color:var(--text-dim)}.breadcrumb a{color:var(--text-muted);text-decoration:none;transition:color .15s}.breadcrumb a:hover{color:var(--accent)}.breadcrumb .sep{color:var(--text-dim)}.mobile-toggle{display:none;background:none;border:1px solid var(--border);color:var(--text);padding:8px 12px;border-radius:var(--radius);cursor:pointer;font-size:18px}.article-wrapper{max-width:780px;margin:0 auto;padding:40px 32px 80px}.article-wrapper h1{font-size:32px;font-weight:700;margin-bottom:8px;color:var(--text);line-height:1.25;letter-spacing:-.02em}.article-meta{display:flex;gap:16px;align-items:center;margin-bottom:32px;font-size:13px;color:var(--text-dim)}.article-meta .badge{background:var(--accent-subtle);color:var(--accent);padding:3px 12px;border-radius:12px;font-size:12px;font-weight:500}.article-content h2{font-size:24px;font-weight:600;margin:36px 0 16px;color:var(--text);padding-bottom:8px;border-bottom:1px solid var(--border)}.article-content h3{font-size:20px;font-weight:600;margin:28px 0 12px;color:var(--text)}.article-content h4{font-size:17px;font-weight:600;margin:24px 0 10px;color:var(--text)}.article-content h5{font-size:15px;font-weight:600;margin:20px 0 8px;color:var(--text-muted)}.article-content p{margin-bottom:16px;color:var(--text);line-height:1.75}.article-content ol,.article-content ul{margin:0 0 16px 20px}.article-content li{margin-bottom:8px;color:var(--text);line-height:1.65}.article-content hr{border:none;border-top:1px solid var(--border);margin:32px 0}.article-content a{color:var(--accent);text-decoration:none}.article-content a:hover{text-decoration:underline}.article-content strong{font-weight:600;color:var(--text)}.article-nav{display:flex;gap:16px;margin-top:48px;padding-top:24px;border-top:1px solid var(--border)}.article-nav-btn{flex:1 1;padding:16px;background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);cursor:pointer;transition:all .2s;text-align:left;color:var(--text)}.article-nav-btn:hover{border-color:var(--accent);box-shadow:var(--shadow-md)}.article-nav-btn .label{font-size:12px;color:var(--text-dim);margin-bottom:4px}.article-nav-btn .title{font-size:14px;font-weight:500}.article-nav-btn.next{text-align:right}.home-hero{text-align:center;padding:64px 32px 40px;background:linear-gradient(180deg,var(--bg-sidebar) 0,var(--bg) 100%)}.home-hero h1{font-size:38px;font-weight:700;margin-bottom:12px;color:var(--text);letter-spacing:-.03em}.home-hero p{font-size:16px;color:var(--text-muted);max-width:480px;margin:0 auto 28px;line-height:1.6}.home-search{max-width:480px;margin:0 auto;position:relative}.home-search input{width:100%;padding:14px 20px;background:var(--bg);border:1px solid var(--border);border-radius:12px;color:var(--text);font-size:15px;outline:none;box-shadow:var(--shadow-sm);transition:border-color .2s,box-shadow .2s}.home-search input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-subtle),var(--shadow-sm)}.home-search input::placeholder{color:var(--text-dim)}.section-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));grid-gap:16px;gap:16px;padding:0 32px 60px;max-width:1000px;margin:0 auto}.section-card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius);padding:24px;cursor:pointer;transition:all .2s;box-shadow:var(--shadow-sm)}.section-card:hover{border-color:var(--accent);transform:translateY(-2px);box-shadow:var(--shadow-md)}.section-card .icon{font-size:28px;margin-bottom:12px}.section-card h3{font-size:16px;font-weight:600;margin-bottom:6px;color:var(--text)}.section-card p{font-size:13px;color:var(--text-muted);line-height:1.5}.section-card .count{margin-top:12px;font-size:12px;color:var(--text-dim)}.search-results{max-width:780px;margin:0 auto;padding:20px 32px}.search-result{padding:16px;background:var(--bg);border:1px solid var(--border);border-radius:var(--radius);margin-bottom:8px;cursor:pointer;transition:all .15s;box-shadow:var(--shadow-sm)}.search-result:hover{border-color:var(--accent);box-shadow:var(--shadow-md)}.search-result h4{font-size:15px;font-weight:500;color:var(--text);margin-bottom:4px}.search-result .section-label{font-size:12px;color:var(--accent);font-weight:500}.search-result .snippet{font-size:13px;color:var(--text-dim);margin-top:6px;line-height:1.5}@media (max-width:768px){.sidebar{transform:translateX(-100%)}.sidebar.open{transform:translateX(0)}.main-content{margin-left:0}.mobile-toggle{display:block}.section-grid{grid-template-columns:1fr;padding:0 16px 40px}.article-wrapper{padding:24px 16px 60px}.article-wrapper h1{font-size:24px}.home-hero{padding:40px 16px 24px}.home-hero h1{font-size:28px}.article-nav{flex-direction:column}.content-header{padding:12px 16px}}.sidebar-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.3);z-index:40}@media (max-width:768px){.sidebar-overlay.open{display:block}}.sidebar::-webkit-scrollbar{width:4px}.sidebar::-webkit-scrollbar-track{background:transparent}.sidebar::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}.sidebar::-webkit-scrollbar-thumb:hover{background:var(--text-dim)}