/* 通用样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

/* 侧边栏样式 */
.sidebar {
    width: 300px;
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

.avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    margin-bottom: 10px;
}

.announcement {
    margin: 20px 0;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: 5px;
}

.categories ul {
    list-style: none;
}

.categories li {
    margin: 8px 0;
}

.categories a {
    color: #666;
    text-decoration: none;
}

/* 页首样式 */
.header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    padding: 15px 0;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.main-nav li {
    margin: 0 15px;
}

.main-nav a {
    color: #333;
    text-decoration: none;
    font-size: 16px;
}

/* 页脚样式 */
.footer {
    background-color: #333;
    color: #fff;
    padding: 30px 0;
    margin-top: 50px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.footer-info p {
    margin: 10px 0;
}

.footer a {
    color: #fff;
    text-decoration: none;
    margin: 0 10px;
}

.social-links {
    margin-top: 20px;
}

.social-links a {
    font-size: 24px;
    margin: 0 10px;
    color: #fff;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .main-nav ul {
        margin-top: 15px;
    }
    
    .sidebar {
        width: 100%;
        margin-bottom: 20px;
    }
}