:root{--bg: #f4f6f9;--surface: #ffffff;--surface-2: #f8fafc;--border: #e2e8f0;--text: #1e293b;--text-muted: #64748b;--sidebar-bg: #0f172a;--sidebar-border: #1e293b;--accent: #10b981;--accent-soft: #d1fae5;--link: #0ea5e9;--danger: #ef4444;--code-bg: #0b1220;--code-text: #a7f3d0;--radius: 10px;--radius-sm: 6px;--shadow: 0 1px 3px rgba(15, 23, 42, .08), 0 1px 2px rgba(15, 23, 42, .04);--shadow-lg: 0 8px 24px rgba(15, 23, 42, .12);--font: "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif;--mono: "JetBrains Mono", "Cascadia Code", Consolas, "Courier New", monospace;--sidebar-w: 250px}*{box-sizing:border-box}html,body{margin:0;padding:0}body{font-family:var(--font);line-height:1.65;background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased}.app{min-height:100vh}.sidebar{width:var(--sidebar-w);background:var(--sidebar-bg);color:#e2e8f0;padding:20px 16px;position:fixed;inset:0 auto 0 0;height:100%;overflow-y:auto;border-right:1px solid var(--sidebar-border)}.sidebar h2{text-align:center;color:#fff;font-size:1.15rem;letter-spacing:.03em;margin:0 0 18px;padding-bottom:14px;border-bottom:1px solid var(--sidebar-border)}.sidebar h2:after{content:"";display:block;width:32px;height:3px;margin:10px auto 0;border-radius:2px;background:var(--accent)}.sidebar nav{display:flex;flex-direction:column;gap:4px}.sidebar nav>a,.sidebar .nav-group>a{text-decoration:none;display:block;padding:9px 12px;border-radius:var(--radius-sm);color:#cbd5e1;background:transparent;transition:background .15s ease,color .15s ease;font-size:.95rem}.sidebar nav>a:hover,.sidebar .nav-group>a:hover{background:#ffffff14;color:#fff}.sidebar .nav-group{border-top:1px solid var(--sidebar-border);border-bottom:1px solid var(--sidebar-border);margin:8px 0;padding:8px 0;display:flex;flex-direction:column;gap:2px}.sidebar .nav-label{display:block;color:#94a3b8;font-size:.72rem;text-transform:uppercase;letter-spacing:.08em;padding:6px 12px 4px}.sidebar .mini{margin-left:16px;padding:6px 12px!important;font-size:.88rem;color:#94a3b8;border-left:2px solid transparent;border-radius:0 var(--radius-sm) var(--radius-sm) 0}.sidebar .mini:hover{color:#fff;background:#ffffff0f}.sidebar .mini.active{color:var(--accent);background:#10b9811f;border-left-color:var(--accent)}.sidebar .about-link{margin-top:8px}.content{margin-left:var(--sidebar-w);min-height:100vh;display:flex;flex-direction:column}header{background:var(--sidebar-bg);color:#e2e8f0;padding:22px 32px;text-align:center;border-bottom:3px solid var(--accent)}header h3{color:#fff;margin:0 0 6px;font-size:1.3rem;letter-spacing:.04em}header p{margin:0 auto;max-width:760px;font-size:.95rem;color:#cbd5e1}header p strong{color:var(--accent)}main{padding:28px 32px 40px;flex:1;max-width:920px;width:100%}footer{background:var(--sidebar-bg);color:#94a3b8;text-align:center;padding:16px;font-size:.85rem}footer a,footer a:visited,footer a:hover{text-decoration:none;color:#cbd5e1}h2{color:var(--text);font-size:1.5rem;margin:0 0 6px}h3{color:var(--text);font-size:1.12rem;margin:26px 0 10px}h4{margin:0}section p a{color:var(--link)}pre{background:var(--code-bg);color:var(--code-text);padding:14px 16px;border-radius:var(--radius-sm);overflow-x:auto;font-family:var(--mono);font-size:.9rem;line-height:1.5;border:1px solid #1e293b}code{font-family:var(--mono);background:#e2e8f0;color:#0f172a;padding:.12em .4em;border-radius:4px;font-size:.88em}pre code{background:none;color:inherit;padding:0}.command-list{display:flex;flex-wrap:wrap;gap:8px;padding-left:0;list-style:none}.command-list code{display:inline-block;background:var(--accent-soft);color:#065f46;border:1px solid #a7f3d0}.instruction-list,.success-list{padding-left:22px}.instruction-list li,.success-list li{margin-bottom:12px}.instruction-list li p,.success-list li p{margin:4px 0 8px;color:var(--text-muted)}.level-list{list-style:none;padding-left:0;margin:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:10px}.level-list li{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);transition:border-color .15s ease,box-shadow .15s ease}.level-list li:hover{border-color:var(--accent);box-shadow:var(--shadow)}.level-list a{display:flex;justify-content:space-between;align-items:center;gap:8px;padding:12px 14px;color:var(--text);text-decoration:none;font-size:.95rem}.level-list a:hover{color:var(--accent)}.level-list .category{font-size:.72rem;color:var(--text-muted);background:var(--surface-2);border:1px solid var(--border);border-radius:10px;padding:2px 8px;white-space:nowrap}.nav-level{display:flex;justify-content:space-between;align-items:center;margin-top:32px;padding-top:18px;border-top:1px solid var(--border);gap:12px}.nav-level a{color:var(--link);font-weight:600;text-decoration:none;padding:8px 14px;border:1px solid var(--border);border-radius:var(--radius-sm);background:var(--surface);transition:border-color .15s ease,color .15s ease}.nav-level a:hover{border-color:var(--accent);color:var(--accent)}.hero{background:linear-gradient(135deg,var(--sidebar-bg) 0%,#1e293b 100%);color:#e2e8f0;border-radius:var(--radius);padding:28px;margin-bottom:28px;box-shadow:var(--shadow-lg)}.hero h2{color:#fff;font-size:1.7rem;margin:0 0 8px}.hero p{margin:0 0 10px;max-width:720px}.hero p:last-child{margin-bottom:0}.group-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px}.group-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px;display:flex;flex-direction:column;gap:10px;box-shadow:var(--shadow);transition:transform .15s ease,box-shadow .15s ease,border-color .15s ease}.group-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg);border-color:var(--accent)}.group-card h4{font-size:1.15rem}.badge{align-self:flex-start;background:var(--accent-soft);color:#065f46;font-size:.72rem;font-weight:600;padding:3px 10px;border-radius:12px}.group-card p{margin:0;color:var(--text-muted);font-size:.93rem}.group-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:4px}.btn{display:inline-block;background:var(--accent);color:#022c22;font-weight:600;padding:8px 16px;border-radius:var(--radius-sm);text-decoration:none;transition:background .15s ease,transform .1s ease}.btn:hover{background:#34d399;transform:translateY(-1px)}.btn-ghost{background:transparent;color:var(--link);border:1px solid #7dd3fc}.btn-ghost:hover{background:#ecfeff}.group-card .meta{font-size:.8rem;color:var(--text-muted);margin-top:auto}@media (max-width: 768px){.sidebar{position:static;width:100%;height:auto;border-right:none;border-bottom:1px solid var(--sidebar-border)}.sidebar nav>a{display:none}.sidebar .mini{margin-left:12px}.content{margin-left:0}header{padding:18px 20px}main{padding:20px}}