/* Practice Page Styles */
.practice-page {
    flex: 1;
}

/* 难度选择器 */
.level-selector {
    display: flex;
    gap: 10px;
    padding: 15px 20px;
    background: #f8f9fa;
    border-radius: 12px;
    margin-bottom: 20px;
    overflow-x: auto;
}

.level-btn {
    padding: 8px 16px;
    border-radius: 8px;
    background: white;
    color: #666;
    font-size: 14px;
    font-weight: 500;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
    flex-shrink: 0;
}

.level-btn:hover {
    background: rgba(102, 126, 234, 0.1);
    transform: translateY(-2px);
}

.level-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.practice-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 15px;
    padding: 20px 0;
}

.pinyin-card {
    aspect-ratio: 1;
    background: white;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    font-weight: bold;
    color: var(--primary-color);
    box-shadow: var(--card-shadow);
    cursor: pointer;
    transition: all 0.3s ease;
    user-select: none;
    position: relative;
    overflow: hidden;
}

.pinyin-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.pinyin-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--card-shadow-hover);
}

.pinyin-card:hover::before {
    opacity: 1;
}

.pinyin-card:active {
    transform: scale(0.95);
}

.pinyin-card.playing {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    animation: pulse 0.6s ease;
}

/* Category sections for yunmu */
.category-section {
    margin-bottom: 40px;
}

.category-title {
    font-size: 20px;
    font-weight: bold;
    color: #333;
    margin-bottom: 15px;
    padding-left: 5px;
    border-left: 4px solid var(--primary-color);
}

/* Responsive */
@media (max-width: 600px) {
    .practice-grid {
        grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
        gap: 10px;
    }
    
    .pinyin-card {
        font-size: 28px;
    }
    
    .category-title {
        font-size: 18px;
    }
}