.container{max-width:800px;margin:0 auto;padding:2rem}h1{text-align:center;color:#333;margin-bottom:2rem}.game-section{background:#f9f9f9;padding:2rem;border-radius:8px;margin-bottom:2rem}.difficulty-section{margin-bottom:3rem}.difficulty-section h3{margin-bottom:1rem;font-size:1.3rem;color:#333}.set-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:1rem;margin-bottom:2rem}.set-card{background:#fff;border:2px solid #e0e0e0;border-radius:12px;padding:1.5rem;cursor:pointer;transition:all .3s;text-align:center}.set-card:hover{border-color:#4caf50;transform:translateY(-2px);box-shadow:0 4px 12px #0000001a}.set-card.selected{border-color:#4caf50;background:#f8fdf8}.set-title{font-size:1.2rem;font-weight:700;margin-bottom:.5rem;color:#333}.set-preview{font-size:1.5rem;margin:1rem 0;color:#666;font-weight:700}.set-count{font-size:.9rem;color:#888}.option-group{margin-bottom:1rem}.option-group label{display:block;margin-bottom:.5rem;font-weight:700;color:#333}.button-group{display:flex;gap:.5rem;flex-wrap:wrap}.option-btn.small{padding:.4rem .8rem;background:#fff;border:2px solid #ddd;border-radius:6px;cursor:pointer;transition:all .3s;font-size:.85rem;line-height:1.2}.option-btn.small:hover{border-color:#4caf50}.option-btn.small.active{background:#4caf50;border-color:#4caf50;color:#fff}.modal{position:fixed;top:0;left:0;width:100%;height:100%;background:#00000080;display:flex;align-items:center;justify-content:center;z-index:1000;animation:fadeIn .3s ease}.modal-content{background:#fff;border-radius:12px;width:90%;max-width:500px;max-height:90vh;overflow-y:auto;animation:slideIn .3s ease}.modal-header{display:flex;justify-content:space-between;align-items:center;padding:1.5rem 2rem;border-bottom:1px solid #eee}.modal-header h3{margin:0;color:#333;font-size:1.3rem}.modal-close{background:none;border:none;font-size:2rem;cursor:pointer;color:#999;padding:0;width:30px;height:30px;display:flex;align-items:center;justify-content:center;border-radius:50%;transition:all .3s}.modal-close:hover{background:#f5f5f5;color:#666}.modal-body{padding:1.5rem}.set-info-display{text-align:center;margin-bottom:1.5rem;padding:1rem;background:#f8f9fa;border-radius:8px}.set-preview-large{font-size:2rem;font-weight:700;color:#333;margin-bottom:1rem}.set-description{color:#666;font-size:1rem}.modal-options{display:flex;flex-direction:column;gap:1rem}.modal-footer{padding:1.5rem 2rem;border-top:1px solid #eee;text-align:center}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@keyframes slideIn{0%{opacity:0;transform:translateY(-50px) scale(.9)}to{opacity:1;transform:translateY(0) scale(1)}}.start-btn,.next-btn{background:#4caf50;color:#fff;border:none;padding:1rem 2rem;font-size:1.1rem;border-radius:4px;cursor:pointer;transition:background .3s}.start-btn:hover,.next-btn:hover{background:#45a049}.game-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem;padding:1rem;background:#e8e8e8;border-radius:4px}.game-controls{display:flex;gap:.5rem}.control-btn{background:#fff;border:2px solid #ddd;border-radius:8px;padding:.5rem;cursor:pointer;font-size:1.2rem;transition:all .3s;min-width:40px;height:40px;display:flex;align-items:center;justify-content:center}.control-btn:hover{border-color:#4caf50;background:#f0f8f0}.progress,.score{font-weight:700;font-size:1.1rem}.character-display{text-align:center;margin:2rem 0;padding:2rem;background:#fff;border-radius:8px;box-shadow:0 2px 4px #0000001a}.character-container{display:flex;align-items:center;justify-content:center;gap:1rem}.chinese-char{font-size:4rem;font-weight:700;color:#333;cursor:pointer;transition:all .3s;padding:1rem;border-radius:12px;display:inline-block}.chinese-char:hover{background:#f0f8f0;transform:scale(1.05);box-shadow:0 4px 12px #0000001a}.chinese-char:active{transform:scale(.95)}.copy-btn{background:#fff;border:2px solid #ddd;border-radius:8px;padding:.5rem;cursor:pointer;font-size:1.2rem;transition:all .3s;min-width:40px;height:40px;display:flex;align-items:center;justify-content:center}.copy-btn:hover{border-color:#4caf50;background:#f0f8f0}.copy-btn.copied{background:#4caf50;color:#fff;border-color:#4caf50}.pronunciation-hint{font-size:.9rem;color:#666;margin-top:.5rem;opacity:.8}.options-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1rem;margin:2rem 0;max-width:600px;margin-left:auto;margin-right:auto}.option-btn{padding:1.5rem 1rem;background:#fff;border:3px solid #ddd;border-radius:12px;cursor:pointer;transition:all .3s;font-size:1.1rem;text-align:center;min-height:120px;display:flex;flex-direction:column;align-items:center;justify-content:center;word-wrap:break-word;hyphens:auto;position:relative;gap:.5rem}.option-number{position:absolute;top:8px;left:8px;background:#4caf50;color:#fff;border-radius:50%;width:24px;height:24px;display:flex;align-items:center;justify-content:center;font-size:.8rem;font-weight:700}.option-text{flex:1;display:flex;align-items:center;justify-content:center}.option-btn:after{content:"🔊";position:absolute;top:8px;right:8px;font-size:.8rem;opacity:.6}.option-btn:hover{border-color:#4caf50;background:#f0f8f0}.option-btn.correct{background:#d4edda;border-color:#28a745;color:#155724}.option-btn.incorrect{background:#f8d7da;border-color:#dc3545;color:#721c24}.option-btn.disabled{cursor:not-allowed;opacity:.6}.feedback{text-align:center;padding:1.5rem;margin:2rem 0;border-radius:4px}.feedback.correct{background:#d4edda;color:#155724;border:1px solid #c3e6cb}.feedback.incorrect{background:#f8d7da;color:#721c24;border:1px solid #f5c6cb}.results{text-align:center;font-size:1.2rem;margin:2rem 0}.results>div{margin:1rem 0}.final-score{font-size:2rem;font-weight:700;color:#4caf50}@media (max-width: 600px){.container{padding:1rem}.chinese-char{font-size:3rem}.pronunciation-hint{font-size:.8rem}.game-header{flex-direction:column;gap:1rem}.options-grid{grid-template-columns:1fr;gap:1rem}.option-btn{min-height:80px;padding:1.5rem 1rem}}