:root{--bg: #0f1419;--surface: #1a2129;--surface-2: #232c36;--border: #2e3a47;--text: #e6edf3;--muted: #9aa7b3;--accent: #ff6d5a;--accent-hover: #ff8674;--correct: #2ea043;--correct-bg: #122a18;--wrong: #d84a4a;--wrong-bg: #2a1313;--selected: #3a4858}*{box-sizing:border-box}html,body,#root{margin:0;padding:0;height:100%;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;font-size:16px;line-height:1.5}button{font-family:inherit;font-size:inherit;cursor:pointer}.container{max-width:820px;margin:0 auto;padding:32px 20px 64px}.header{margin-bottom:24px}.header h1{margin:0 0 6px;font-size:28px;letter-spacing:-.01em}.header h2{margin:12px 0 8px;font-size:22px;font-weight:600}.subtitle{margin:0;color:var(--muted)}.btn-link{background:none;border:none;color:var(--muted);padding:0;margin-bottom:8px;font-size:14px}.btn-link:hover{color:var(--text)}.overall-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:20px;margin-bottom:20px}.overall-row{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin-bottom:14px}.overall-label{color:var(--muted);font-size:13px;text-transform:uppercase;letter-spacing:.05em}.overall-value{font-size:42px;font-weight:700;line-height:1;margin-top:4px;color:var(--accent)}.overall-meta{text-align:right;color:var(--muted);font-size:14px}.progress{background:var(--surface-2);height:8px;border-radius:4px;overflow:hidden}.progress.small{height:5px}.progress-bar{height:100%;background:var(--accent);transition:width .2s ease}.complete-banner{margin-top:14px;padding:10px 14px;background:var(--correct-bg);border:1px solid var(--correct);color:#b9f0c5;border-radius:8px;font-weight:500}.sections{display:grid;gap:12px;grid-template-columns:1fr}.section-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:16px 18px;text-align:left;color:var(--text);transition:border-color .12s ease,transform .12s ease}.section-card:hover{border-color:var(--accent)}.section-card:active{transform:translateY(1px)}.section-card-title{font-weight:600;margin-bottom:6px}.section-card-meta{display:flex;justify-content:space-between;gap:12px;color:var(--muted);font-size:14px;margin-bottom:10px}.footer-actions{margin-top:24px;display:flex;justify-content:flex-end}.section-progress-row{display:flex;justify-content:space-between;color:var(--muted);font-size:14px;margin-top:4px}.question-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:22px;margin-bottom:20px}.question-text{font-size:18px;font-weight:500;margin-bottom:18px}.choices{display:grid;gap:10px}.choice{display:flex;align-items:flex-start;gap:12px;background:var(--surface-2);border:1px solid var(--border);border-radius:10px;padding:12px 14px;text-align:left;color:var(--text);transition:background .12s ease,border-color .12s ease}.choice:hover{border-color:var(--accent)}.choice-letter{display:inline-flex;align-items:center;justify-content:center;width:26px;height:26px;border-radius:6px;background:var(--bg);border:1px solid var(--border);font-size:13px;font-weight:600;color:var(--muted);flex-shrink:0}.choice-text{flex:1}.choice-selected{border-color:var(--accent)}.choice-correct{background:var(--correct-bg);border-color:var(--correct)}.choice-correct .choice-letter{background:var(--correct);color:#fff;border-color:var(--correct)}.choice-wrong{background:var(--wrong-bg);border-color:var(--wrong)}.choice-wrong .choice-letter{background:var(--wrong);color:#fff;border-color:var(--wrong)}.choice-dim{opacity:.6}.feedback{margin-top:18px;padding:14px 16px;border-radius:10px;border:1px solid var(--border)}.feedback-correct{background:var(--correct-bg);border-color:var(--correct)}.feedback-wrong{background:var(--wrong-bg);border-color:var(--wrong)}.feedback-title{font-weight:600;margin-bottom:6px}.feedback-answer{margin-bottom:8px;font-size:14px}.feedback-explanation{font-size:14px;color:var(--text)}.feedback-hint{margin-top:8px;font-size:12px;color:var(--muted)}.nav-row{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}.dots{display:flex;gap:6px}.dot{width:32px;height:32px;border-radius:8px;background:var(--surface-2);border:1px solid var(--border);color:var(--muted);font-size:13px;font-weight:600;display:inline-flex;align-items:center;justify-content:center}.dot:hover{border-color:var(--accent);color:var(--text)}.dot-active{background:var(--accent);color:#fff;border-color:var(--accent)}.dot-correct{border-color:var(--correct);color:#b9f0c5}.dot-wrong{border-color:var(--wrong);color:#f5b9b9}.btn-primary,.btn-secondary{border-radius:8px;padding:10px 16px;border:1px solid var(--border);background:var(--surface-2);color:var(--text);font-weight:500;transition:background .12s ease,border-color .12s ease}.btn-primary{background:var(--accent);border-color:var(--accent);color:#fff}.btn-primary:hover{background:var(--accent-hover);border-color:var(--accent-hover)}.btn-secondary:hover{border-color:var(--accent)}.btn-primary:disabled,.btn-secondary:disabled{opacity:.4;cursor:not-allowed}@media (max-width: 540px){.overall-row{flex-direction:column;align-items:flex-start}.overall-meta{text-align:left}.nav-row{flex-direction:column;align-items:stretch}.dots{justify-content:center;flex-wrap:wrap}}