:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light dark;--bg:#f5f6f8;--card:#fff;--text:#1a1a1a;--muted:#6b7280;--accent:#2563eb;--border:#e5e7eb;--ok:#16a34a;--err:#dc2626}@media (prefers-color-scheme:dark){:root{--lightningcss-light: ;--lightningcss-dark:initial}}*{box-sizing:border-box}body{background:var(--bg);color:var(--text);margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}.shell{max-width:860px;margin:0 auto;padding:0 16px 40px}header{flex-wrap:wrap;align-items:center;gap:16px;padding:16px 0;display:flex}.brand{font-size:18px;font-weight:700}nav{flex-wrap:wrap;flex:1;gap:6px;display:flex}header button,nav button{border:1px solid var(--border);background:var(--card);color:var(--text);cursor:pointer;border-radius:8px;padding:6px 12px;font-size:14px}nav button.active{background:var(--accent);color:#fff;border-color:var(--accent)}main{gap:16px;display:grid}.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:20px}.auth-wrap{justify-content:center;padding-top:8vh;display:flex}.auth-wrap .card{gap:12px;width:360px;display:grid}h1,h2,h3{margin:0 0 8px}.muted{color:var(--muted);font-size:14px}input,select{border:1px solid var(--border);background:var(--card);color:var(--text);border-radius:8px;width:100%;padding:9px 11px;font-size:14px}.row{flex-wrap:wrap;align-items:center;gap:10px;margin:10px 0;display:flex}.tabs{gap:6px;display:flex}.tabs button{flex:1}button.primary{background:var(--accent);color:#fff;cursor:pointer;border:none;border-radius:8px;padding:10px 16px;font-size:14px;font-weight:600}button.primary:disabled{opacity:.5;cursor:not-allowed}button.link{color:var(--accent);cursor:pointer;background:0 0;border:none;padding:0;text-decoration:underline}.error{color:var(--err);font-size:14px}.ok{color:var(--ok);font-weight:600}.err{color:var(--err);font-weight:600}.q{margin:12px 0;font-size:16px;font-weight:600}.q-block{border-top:1px solid var(--border);padding:12px 0}.options{gap:6px;margin:10px 0;display:grid}.options label{border:1px solid var(--border);cursor:pointer;border-radius:8px;align-items:center;gap:8px;width:fit-content;min-width:160px;padding:8px 10px;display:flex}.options label.correct{border-color:var(--ok);background:#16a34a14}table{border-collapse:collapse;width:100%;margin:10px 0;font-size:14px}th,td{text-align:left;border-bottom:1px solid var(--border);padding:8px 10px}th{color:var(--muted);font-weight:600}.tier{margin-top:16px}.chat{border:1px solid var(--border);border-radius:10px;flex-direction:column;gap:8px;height:300px;margin:10px 0;padding:12px;display:flex;overflow-y:auto}.msg{white-space:pre-wrap;border-radius:10px;max-width:80%;padding:8px 12px;font-size:14px;line-height:1.5}.msg.user{background:var(--accent);color:#fff;align-self:flex-end}.msg.assistant{background:var(--bg);align-self:flex-start}