/* 全局样式 */
:root {
    --primary-color: #2ecc71; /* 绿色 */
    --secondary-color: #27ae60;
    --bg-light: #f8f9fa; /* 浅灰 */
    --text-dark: #2d3436; /* 黑/深灰 */
    --text-muted: #636e72; /* 灰 */
    --white: #ffffff;
    --border-radius: 12px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
}

body {
    background-color: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

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

/* 导航栏 */
.navbar {
    background: var(--white);
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
}

.user-nav a {
    padding: 8px 16px;
    border-radius: 20px;
    background: var(--bg-light);
    font-size: 14px;
    transition: all 0.3s;
}

.user-nav a:hover {
    background: var(--primary-color);
    color: var(--white);
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    border: none;
    cursor: pointer;
    font-size: 16px;
    transition: transform 0.2s, opacity 0.2s;
    text-align: center;
}

.btn:active {
    transform: scale(0.98);
}

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

/* 卡片 */
.card {
    background: var(--white);
    border-radius: var(--border-radius);
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.02);
}

/* 响应式网格 */
.grid {
    display: grid;
    gap: 20px;
}

@media (min-width: 768px) {
    .grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
    .grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
    .grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 767px) {
    .grid-cols-mobile-1 { grid-template-columns: 1fr; }
}

/* 模块列表样式 */
.module-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 30px;
    text-align: center;
    transition: transform 0.3s;
    border: 1px solid #eee;
}

.module-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
}

.module-icon {
    font-size: 40px;
    margin-bottom: 15px;
    display: block;
}