/* 基础样式与纯色主题变量设置 */
:root {
    --bg-color: #f4f7f6;
    --card-bg: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --accent-color: #2563eb;
    --accent-hover: #1d4ed8;
    --border-color: #e5e7eb;
    
    --header-height: 64px;
    --radius-lg: 16px;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* 顶部导航栏，两端对齐，Logo 绝对居中 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 24px;
    font-weight: 700;
    color: var(--accent-color);
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.logo i {
    font-size: 28px;
}

.admin-link {
    margin-left: auto;
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
}

.admin-link:hover {
    color: var(--accent-color);
}

/* 布局容器，内容居中展示 */
.container {
    display: flex;
    justify-content: center;
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
}

/* 主内容区 */
.main-content {
    width: 100%;
    max-width: 1200px;
    padding: 40px 24px;
}

/* 卡片网格布局，自适应响应 */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

/* 卡片极简设计，只包含标题 */
.card {
    background-color: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 24px;
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: inherit;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    min-height: 120px;
}

/* 纯色高亮边框动效 */
.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background-color: var(--accent-color);
    transform: scaleY(0);
    transition: transform 0.3s ease;
    transform-origin: bottom;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: rgba(37, 99, 235, 0.3);
}

.card:hover::before {
    transform: scaleY(1);
    transform-origin: top;
}

.card-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
}

/* 移动端响应式兼容 */
@media (max-width: 768px) {
    .main-content {
        padding: 24px 16px;
    }

    .cards-grid {
        grid-template-columns: repeat(auto-fill, minmax(100%, 1fr));
        gap: 16px;
    }
}