/* 基础样式 */
:root {
    --primary-color: #4361ee;
    --secondary-color: #3f37c9;
    --accent-color: #4cc9f0;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #333333;
    --text-light: #666666;
    --border-color: #e0e0e0;
    --hover-color: #f1f5fe;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background-color: var(--bg-color);
    color: var(--text-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: color 0.3s;
}

a:hover {
    color: var(--secondary-color);
}

/* 顶部区域 */
header {
    background-color: var(--primary-color);
    color: white;
    padding: 3rem 0;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

header p {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
    opacity: 0.9;
}

.search-box {
    display: flex;
    max-width: 500px;
    margin: 0 auto;
}

.search-box input {
    flex: 1;
    padding: 12px 20px;
    border: none;
    border-radius: 30px 0 0 30px;
    font-size: 1rem;
}

.search-box button {
    background-color: var(--accent-color);
    color: white;
    border: none;
    padding: 0 25px;
    border-radius: 0 30px 30px 0;
    cursor: pointer;
    transition: background-color 0.3s;
}

.search-box button:hover {
    background-color: #3aafdf;
}

/* 分类标签 */
nav {
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    margin-bottom: 2rem;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.category-tabs {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
}

.tab-btn {
    background: none;
    border: none;
    padding: 8px 20px;
    font-size: 1rem;
    color: var(--text-light);
    cursor: pointer;
    border-radius: 20px;
    transition: all 0.3s;
}

.tab-btn:hover {
    background-color: var(--hover-color);
    color: var(--primary-color);
}

.tab-btn.active {
    background-color: var(--primary-color);
    color: white;
}

/* 子分类版块 */
.subcategory-section {
    margin-bottom: 30px;
}

.subcategory-title {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--text-color);
    padding-bottom: 8px;
    border-bottom: 2px solid var(--accent-color);
    display: inline-block;
}

.subcategory-description {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 15px;
}

.subcategory-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

/* 卡片区域 */
#cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 3rem;
}

.category-heading {
    grid-column: 1 / -1;
    margin-top: 20px;
    margin-bottom: 10px;
    font-size: 1.5rem;
    color: var(--primary-color);
    border-left: 4px solid var(--accent-color);
    padding-left: 10px;
}

.card {
    background-color: var(--card-bg);
    border-radius: 10px;
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    position: relative;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.card-content {
    padding: 20px;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.card-title {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.card-description {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 15px;
    line-height: 1.5;
}

.card-details {
    overflow: hidden;
    max-height: 0;
    opacity: 0;
    transition: max-height 0.5s ease, opacity 0.3s ease, margin 0.3s ease;
    margin-bottom: 0;
}

.card.expanded .card-details {
    max-height: 500px;
    opacity: 1;
    margin-bottom: 15px;
}

.card-details p {
    color: var(--text-light);
    font-size: 0.9rem;
    line-height: 1.6;
    background-color: var(--hover-color);
    padding: 12px;
    border-radius: 8px;
    border-left: 3px solid var(--primary-color);
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
}

.toggle-details {
    background: none;
    border: none;
    color: var(--primary-color);
    font-size: 0.85rem;
    cursor: pointer;
    padding: 5px 0;
    font-weight: 500;
    transition: color 0.3s;
}

.toggle-details:hover {
    color: var(--secondary-color);
}

.card-link {
    display: block;
    text-align: right;
    font-weight: 500;
    font-size: 0.9rem;
}

.card-category {
    display: inline-block;
    background-color: var(--hover-color);
    color: var(--primary-color);
    font-size: 0.8rem;
    padding: 4px 10px;
    border-radius: 20px;
    margin-bottom: 10px;
}

/* 子分类标签 */
.subcategory-tag {
    display: inline-block;
    background-color: var(--secondary-color);
    color: white;
    font-size: 0.7rem;
    padding: 2px 8px;
    border-radius: 12px;
    margin-left: 5px;
    vertical-align: middle;
}

/* 无结果提示 */
.no-results {
    grid-column: 1 / -1;
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-light);
    font-size: 1.2rem;
    background-color: var(--card-bg);
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
}

/* 底部区域 */
footer {
    background-color: white;
    border-top: 1px solid var(--border-color);
    padding: 1.5rem 0;
    text-align: center;
    color: var(--text-light);
}

/* 响应式设计 */
@media (max-width: 768px) {
    header {
        padding: 2rem 0;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .category-tabs {
        overflow-x: auto;
        padding-bottom: 5px;
        justify-content: flex-start;
    }
    
    #cards-container, .subcategory-container {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.8rem;
    }
    
    .search-box input {
        padding: 10px 15px;
    }
    
    .search-box button {
        padding: 0 15px;
    }
    
    #cards-container, .subcategory-container {
        grid-template-columns: 1fr;
    }
    
    .card-footer {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .card-link {
        text-align: left;
    }
}