:root{--bg:#0f172a;--card:#111827;--text:#e5e7eb;--accent:#22c55e;--muted:#94a3b8;--danger:#ef4444;--warn:#f59e0b}
*{box-sizing:border-box;font-family:Inter,system-ui,Segoe UI,Roboto,sans-serif}
body{margin:0;background:linear-gradient(180deg,#0b1024,#111827);color:var(--text);min-height:100vh;display:grid;place-items:center;padding:20px}
.app{max-width:820px;width:100%}
h1{margin:0 0 6px}.subtitle{margin:0 0 18px;color:var(--muted)}
.home-btn{font-size:32px;font-weight:700;background:none;border:none;padding:0;cursor:pointer;color:var(--text)}
.home-btn:hover{opacity:.9;background:none}
.card{background:rgba(17,24,39,.95);border:1px solid #1f2937;border-radius:14px;padding:18px;margin-bottom:14px}
.hidden{display:none}
.settings{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:10px;margin-bottom:12px}
label{display:flex;flex-direction:column;gap:6px;color:var(--muted);font-size:14px}
select{background:#0b1220;color:var(--text);border:1px solid #374151;padding:8px;border-radius:8px}
.toggle{flex-direction:row;align-items:center;gap:8px;padding-top:22px}
.buttons{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:10px}
button{background:#1f2937;color:var(--text);border:1px solid #374151;padding:10px 12px;border-radius:10px;cursor:pointer}
button:hover{background:#263244}
.top-row{display:flex;justify-content:space-between;color:var(--muted);margin-bottom:8px}
.graph-box{margin:8px 0 12px 0;display:none}
.graph-box svg{max-width:100%;height:auto;background:#0b1220;border:1px solid #334155;border-radius:8px}
.answers{display:grid;gap:8px;margin:12px 0}
.answer-btn{text-align:left}
.answer-btn.correct{border-color:var(--accent);background:#052e1a}
.answer-btn.wrong{border-color:var(--danger);background:#3a1010}
.feedback{min-height:22px;color:var(--muted)}
.actions{display:flex;gap:10px;justify-content:flex-end}
.meta{color:var(--muted);font-size:14px}
#timer.low{color:var(--warn)}
#timer.done{color:var(--danger)}