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

body {
    font-family: 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f4f4f4;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Header 样式 */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 1rem 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h1 {
    font-size: 24px;
}

.logo a {
    color: #fff;
    text-decoration: none;
}

nav ul {
    list-style: none;
    display: flex;
}

nav ul li {
    margin: 0 15px;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
    padding: 5px 10px;
    border-radius: 5px;
    transition: background 0.3s;
}

nav ul li a:hover {
    background: rgba(255,255,255,0.2);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 15px;
}

.user-menu a {
    color: #fff;
    text-decoration: none;
    padding: 5px 15px;
    border: 1px solid #fff;
    border-radius: 5px;
    transition: all 0.3s;
}

.user-menu a:hover {
    background: #fff;
    color: #764ba2;
}

.vip-badge {
    background: gold;
    color: #333;
    padding: 2px 8px;
    border-radius: 3px;
    font-size: 12px;
    font-weight: bold;
}

/* Main 内容区域 */
main {
    min-height: calc(100vh - 200px);
    padding: 30px 0;
}

/* 资源卡片网格 */
.resource-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.resource-card {
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.resource-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.resource-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.resource-info {
    padding: 15px;
}

.resource-title {
    font-size: 18px;
    margin-bottom: 10px;
    color: #333;
}

.resource-desc {
    font-size: 14px;
    color: #666;
    margin-bottom: 10px;
    height: 40px;
    overflow: hidden;
}

.resource-meta {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: #999;
    margin-bottom: 10px;
}

.vip-tag {
    background: gold;
    color: #333;
    padding: 2px 8px;
    border-radius: 3px;
    font-size: 12px;
    font-weight: bold;
}

.download-btn {
    display: inline-block;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 8px 20px;
    text-decoration: none;
    border-radius: 5px;
    transition: opacity 0.3s;
}

.download-btn:hover {
    opacity: 0.9;
}

/* 后台管理样式 */
.admin-container {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 20px;
}

.admin-sidebar {
    background: #fff;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.admin-sidebar ul {
    list-style: none;
}

.admin-sidebar li {
    margin-bottom: 10px;
}

.admin-sidebar a {
    display: block;
    padding: 10px;
    color: #333;
    text-decoration: none;
    border-radius: 5px;
    transition: background 0.3s;
}

.admin-sidebar a:hover,
.admin-sidebar a.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
}

.admin-content {
    background: #fff;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

/* 表单样式 */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

.form-control {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 14px;
}

.form-control:focus {
    outline: none;
    border-color: #764ba2;
    box-shadow: 0 0 5px rgba(118, 75, 162, 0.3);
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    transition: opacity 0.3s;
}

.btn:hover {
    opacity: 0.9;
}

.btn-danger {
    background: linear-gradient(135deg, #f56565 0%, #c53030 100%);
}

/* 表格样式 */
.table {
    width: 100%;
    border-collapse: collapse;
}

.table th,
.table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

.table th {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
}

.table tr:hover {
    background: #f5f5f5;
}

/* Footer 样式 */
footer {
    background: #333;
    color: #fff;
    text-align: center;
    padding: 20px 0;
    margin-top: 30px;
}

footer a {
    color: #fff;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* 响应式设计 */
@media (max-width: 768px) {
    header .container {
        flex-direction: column;
        gap: 10px;
    }
    
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    nav ul li {
        margin: 5px;
    }
    
    .resource-grid {
        grid-template-columns: 1fr;
    }
    
    .admin-container {
        grid-template-columns: 1fr;
    }
}