/* 严禁省略代码 */
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: #212529;
    background-color: #f8f9fa;
    display: flex;
    min-height: 100vh;
}

/* 左侧导航栏样式 */
.sidebar {
    width: 250px;
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 20px;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    box-shadow: 2px 0 5px rgba(0,0,0,0.1);
}

.sidebar h2 {
    color: #3498db;
    margin-top: 0;
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.nav-button {
    text-align: center;
    margin-bottom: 20px;
}

.nav-button button {
    width: 100%;
    padding: 10px 15px;
    border: none;
    background-color: #3498db;
    color: #fff;
    font-size: 1rem;
    cursor: pointer;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.nav-button button:hover {
    background-color: #2980b9;
}

.sidebar ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.sidebar ul li {
    margin-bottom: 5px;
}

.sidebar ul li a {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #ecf0f1;
    text-decoration: none;
    padding: 12px 15px;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.sidebar ul li a:hover {
    background-color: #34495e;
}

.sidebar ul li ul.nav-submenu {
    list-style-type: none;
    padding: 0;
    margin: 5px 0 5px 20px;
    display: none; /* 默认隐藏二级菜单 */
}

.sidebar ul li ul.nav-submenu li a {
    padding: 8px 15px;
    font-size: 0.9rem;
}

/* 主内容区样式 */
.main-content {
    flex-grow: 1;
    padding: 20px;
    box-sizing: border-box;
    overflow-y: auto;
}

.page-header {
    padding-bottom: 15px;
    border-bottom: 2px solid #3498db;
    margin-bottom: 20px;
}

.page-header h2 {
    margin: 0;
    font-size: 1.8rem;
    color: #34495e;
}

.page-content {
    background-color: #ffffff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

/* 通用按钮样式 */
button {
    border: none;
    padding: 8px 16px;
    font-size: 0.9rem;
    cursor: pointer;
    border-radius: 4px;
    transition: background-color 0.3s ease;
}

button:hover {
    opacity: 0.9;
}