:root {
    --primary-color: #3b82f6;
    --hover-color: #2563eb;
    --gap: 1.5rem;
}

/* 基础布局 */
body {
    font-family: system-ui, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 2rem;
    background: #f8fafc;
}

.header {
    text-align: center;
    margin-bottom: 3rem;
}

/* 分类导航 */
.categories {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1.5rem;
}

.category-btn {
    padding: 0.75rem 1.5rem;
    border: 2px solid #e2e8f0;
    border-radius: 0.5rem;
    background: white;
    cursor: pointer;
    transition: all 0.2s;
}

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

/* 图片网格 */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--gap);
    max-width: 1200px;
    margin: 0 auto;
}

.gallery-card {
    background: white;
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease;
}

.gallery-card:hover {
    transform: translateY(-5px);
}

.image-card {
    display: block;
    position: relative;
    height: 300px;
}

.image-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.category-tag {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.875rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .gallery-grid {
        grid-template-columns: 1fr;
    }
    
    .category-btn {
        width: 100%;
    }
}