* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "微軟正黑體", sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.main-title {
    text-align: center;
    color: #333;
    margin-bottom: 2rem;
    font-size: 2.5rem;
}

.section-title {
    font-size: 1.5rem;
    color: #333;
    margin: 2rem 0 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e0e0e0;
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.card {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    cursor: pointer;
    transition: transform 0.2s;
    position: relative;
    text-decoration: none;
    color: inherit;
}

.card:hover {
    transform: translateY(-4px);
}

.card h3 {
    text-align: center;
    margin: 0;
}

.level-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    font-weight: bold;
    color: white;
}

/* 詞彙卡片樣式 */
.vocabulary-card {
    background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
}

.vocabulary-card .level-badge {
    background: #2196f3;
}

.vocabulary-card:nth-child(2) {
    background: linear-gradient(135deg, #f3e5f5 0%, #e1bee7 100%);
}

.vocabulary-card:nth-child(2) .level-badge {
    background: #9c27b0;
}

/* 文法卡片樣式 */
.grammar-card {
    background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%);
}

.grammar-card .level-badge {
    background: #4caf50;
}

.grammar-card:nth-child(2) {
    background: linear-gradient(135deg, #c8e6c9 0%, #81c784 100%);
}

/* 助詞卡片樣式 */
.particle-card {
    background: linear-gradient(135deg, #f3e5f5 0%, #e1bee7 100%);
}

.particle-card .level-badge {
    background: #9c27b0;
}

.particle-card:nth-child(2) {
    background: linear-gradient(135deg, #e1bee7 0%, #ce93d8 100%);
}

.particle-card:nth-child(3) {
    background: linear-gradient(135deg, #ce93d8 0%, #ba68c8 100%);
}

/* 助詞學習按鈕樣式 */
.category {
    margin-bottom: 2rem;
}

.level-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    padding: 1rem;
}

.level-button {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    background: white;
    border-radius: 8px;
    text-decoration: none;
    color: #333;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
    text-align: center;
    min-height: 100px;
}

.level-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    background: #4caf50;
    color: white;
}

.particle-label {
    display: block;
    font-size: 2em;
    margin-top: 0.5rem;
    color: #4caf50;
    font-weight: bold;
}

.level-button:hover .particle-label {
    color: white;
}

/* 響應式設計 */
@media (max-width: 768px) {
    .cards-grid {
        grid-template-columns: 1fr;
    }
    
    .container {
        padding: 1rem;
    }
    
    .main-title {
        font-size: 2rem;
    }
    
    .level-buttons {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .level-buttons {
        grid-template-columns: 1fr;
    }
}