/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Microsoft YaHei', Arial, sans-serif;
}

:root {
    /* 主要颜色 */
    --primary-color: #4a6cf7;
    --primary-dark: #3a56e8;
    --secondary-color: #6c757d;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #333333;
    --border-color: #e1e5eb;
    
    /* 尺寸变量 */
    --header-height: 60px;
    --footer-height: 50px;
    --border-radius: 8px;
}

body {
    background: linear-gradient(135deg, #e9ecff 0%, #f2f6ff 100%);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* 头部样式 */
header {
    background-color: var(--card-bg);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    height: var(--header-height);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.logo h1 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: bold;
}

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

nav ul li {
    margin-left: 1.5rem;
}

nav ul li a {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
}

nav ul li a:hover {
    color: var(--primary-color);
    background-color: rgba(74, 108, 247, 0.05);
}

nav ul li a.active {
    color: var(--primary-color);
    background-color: rgba(74, 108, 247, 0.1);
}

/* 主内容区域 */
main {
    flex: 1;
    padding: 2rem;
}

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

.card {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    padding: 2rem;
    margin-bottom: 2rem;
}

.section {
    display: none;
}

.section.active {
    display: block;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    background-color: var(--secondary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
    text-align: center;
}

.btn:hover {
    opacity: 0.9;
}

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

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

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

/* 表格通用样式 */
table {
    width: 100%;
    border-collapse: collapse;
}

table th, 
table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

table th {
    background-color: rgba(74, 108, 247, 0.05);
    font-weight: 600;
}

/* 表单样式 */
.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 1.5rem;
}

/* 空状态提示 */
.empty-message {
    text-align: center;
    padding: 2rem;
    color: var(--secondary-color);
}

/* 页脚样式 */
footer {
    height: var(--footer-height);
    background-color: var(--card-bg);
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--secondary-color);
    font-size: 0.9rem;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
}

/* 响应式设计 */
@media screen and (max-width: 768px) {
    header {
        flex-direction: column;
        height: auto;
        padding: 1rem;
    }
    
    nav ul {
        margin-top: 1rem;
    }
    
    nav ul li {
        margin-left: 0.5rem;
        margin-right: 0.5rem;
    }
    
    main {
        padding: 1rem;
    }
    
    .card {
        padding: 1.5rem;
    }
}

/* 返回首页按钮 */
.back-btn {
    position: fixed;
    left: 15px;
    top: 70px;
    transform: none;
    background-color: #FF5D5D;
    color: white;
    padding: 8px 15px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    z-index: 999;
}

.back-btn:hover {
    background-color: #ff4040;
    box-shadow: 0 3px 8px rgba(0,0,0,0.3);
}

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