*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:system-ui,-apple-system,sans-serif;background:#f5f5f5;color:#1a1a1a;min-height:100vh;display:flex;flex-direction:column;align-items:center;padding:2rem 1rem}header{width:100%;max-width:600px;margin-bottom:2rem}.back-link{color:#555;text-decoration:none;font-size:.9rem}.back-link:hover{color:#000}#app,#score-screen{background:#fff;border-radius:16px;padding:2rem;width:100%;max-width:600px;box-shadow:0 2px 12px #00000014}h1{font-size:1.8rem;margin-bottom:1.5rem}#progress{font-size:.85rem;color:#888;margin-bottom:1rem}#question-container{font-size:1.15rem;font-weight:600;margin-bottom:1.5rem;line-height:1.5}#choices-container{display:flex;flex-direction:column;gap:.75rem;margin-bottom:1.25rem}.choice-btn{padding:.75rem 1rem;border:2px solid #e0e0e0;border-radius:8px;background:#fff;font-size:1rem;cursor:pointer;text-align:left;transition:border-color .15s,background .15s}.choice-btn:hover{border-color:#999;background:#fafafa}.choice-btn.selected-correct{border-color:#22c55e;background:#f0fdf4;color:#166534}.choice-btn.selected-wrong{border-color:#ef4444;background:#fef2f2;color:#991b1b}.choice-btn.reveal-correct{border-color:#22c55e;background:#f0fdf4}#feedback{font-weight:600;font-size:1rem;min-height:1.5rem;margin-bottom:1rem}#feedback.correct{color:#16a34a}#feedback.wrong{color:#dc2626}#next-btn,#restart-btn{padding:.75rem 2rem;background:#1a1a1a;color:#fff;border:none;border-radius:8px;font-size:1rem;cursor:pointer;transition:background .15s}#next-btn:hover,#restart-btn:hover{background:#333}#score-screen{text-align:center;display:flex;flex-direction:column;align-items:center;gap:1rem}#score-screen h2{font-size:1.75rem}#final-score{font-size:1.2rem;color:#444}