*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}:root{--bg: #0f1117;--surface: #1a1d27;--border: #2a2d3a;--accent: #4f8ef7;--accent-dim: #2a4a8a;--text: #e2e8f0;--muted: #8892a4;--danger: #f87171;--success: #34d399;--radius: 8px;font-family:Inter,system-ui,sans-serif}body{background:var(--bg);color:var(--text);min-height:100vh;line-height:1.6}.container{max-width:900px;margin:0 auto;padding:2rem 1.5rem}nav{background:var(--surface);border-bottom:1px solid var(--border);padding:0 1.5rem;height:56px;display:flex;align-items:center;justify-content:space-between}nav .brand{font-weight:700;font-size:1.1rem;color:var(--accent);text-decoration:none}nav .nav-links{display:flex;gap:1rem;align-items:center}nav a,nav button.link{color:var(--muted);text-decoration:none;font-size:.9rem;background:none;border:none;cursor:pointer;transition:color .15s}nav a:hover,nav button.link:hover{color:var(--text)}nav a.active{color:var(--accent)}.btn{display:inline-block;padding:.55rem 1.25rem;border-radius:var(--radius);font-size:.9rem;font-weight:500;cursor:pointer;border:none;transition:opacity .15s,transform .1s;text-decoration:none}.btn:hover{opacity:.88;transform:translateY(-1px)}.btn:active{transform:translateY(0)}.btn-primary{background:var(--accent);color:#fff}.btn-outline{background:transparent;border:1px solid var(--border);color:var(--text)}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.5rem}.form-group{margin-bottom:1.25rem}.form-group label{display:block;font-size:.85rem;color:var(--muted);margin-bottom:.4rem}.form-group input{width:100%;background:var(--bg);border:1px solid var(--border);border-radius:var(--radius);padding:.6rem .9rem;color:var(--text);font-size:.95rem;outline:none;transition:border-color .15s}.form-group input:focus{border-color:var(--accent)}.alert{padding:.75rem 1rem;border-radius:var(--radius);font-size:.9rem;margin-bottom:1rem}.alert-error{background:#f871711a;border:1px solid var(--danger);color:var(--danger)}.alert-success{background:#34d3991a;border:1px solid var(--success);color:var(--success)}h1{font-size:2rem;font-weight:700;margin-bottom:.5rem}h2{font-size:1.4rem;font-weight:600;margin-bottom:1rem}p.lead{color:var(--muted);margin-bottom:1.5rem}.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:1rem;margin-top:1.5rem}.topic-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.25rem;transition:border-color .15s}.topic-card:hover{border-color:var(--accent-dim)}.topic-card h3{font-size:1rem;font-weight:600;margin-bottom:.4rem}.topic-card p{font-size:.88rem;color:var(--muted)}.topic-card .tag{display:inline-block;font-size:.75rem;padding:.15rem .5rem;border-radius:4px;background:var(--accent-dim);color:var(--accent);margin-top:.75rem}.locked-banner{text-align:center;padding:3rem 1.5rem;border:1px dashed var(--border);border-radius:var(--radius);margin-top:2rem;color:var(--muted)}.locked-banner .lock-icon{font-size:2.5rem;margin-bottom:1rem}.locked-banner p{margin-bottom:1.25rem}.auth-wrapper{max-width:420px;margin:4rem auto 0}.auth-wrapper h1{font-size:1.6rem;margin-bottom:.4rem}.auth-wrapper .subtitle{color:var(--muted);margin-bottom:2rem;font-size:.9rem}.auth-footer{text-align:center;margin-top:1.25rem;font-size:.88rem;color:var(--muted)}.auth-footer a{color:var(--accent);text-decoration:none}