* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
}

body {
    background-color: #f7f9fc;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航条样式 */
header {
    background-color: #2c3e50;
    color: white;
    padding: 15px 0;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: #3498db;
    display: flex;
    align-items: center;
}

.logo i {
    margin-right: 8px;
    font-size: 2rem;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    font-size: 1.1rem;
    padding: 8px 12px;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.nav-links a:hover {
    background-color: #3498db;
    color: white;
}

.contact-info {
    display: flex;
    align-items: center;
    background-color: #1a252f;
    padding: 10px 15px;
    border-radius: 4px;
}

.contact-info i {
    margin-right: 8px;
    color: #3498db;
}

/* 公告栏样式 */
.announcement {
    background-color: #fff;
    margin: 25px 0;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    border-left: 5px solid #3498db;
}

.announcement h2 {
    color: #2c3e50;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
}

.announcement h2 i {
    margin-right: 10px;
    color: #e74c3c;
}

.announcement-content {
    padding: 10px 0;
    color: #555;
}


/* 主要内容区样式 */
.main-content {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    padding: 40px;
    min-height: 400px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    margin-bottom: 40px;
    text-align: center;
}

.main-content h3 {
    color: #7f8c8d;
    margin-bottom: 20px;
    font-weight: 400;
}

.content-placeholder {
    color: #95a5a6;
    font-size: 1.2rem;
}

.content-placeholder i {
    font-size: 3rem;
    margin-bottom: 20px;
    color: #bdc3c7;
}

/* 版权信息样式 */
footer {
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 30px 0;
    text-align: center;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.copyright {
    margin-bottom: 15px;
    font-size: 1rem;
}

.footer-links {
    display: flex;
    gap: 25px;
    list-style: none;
    margin-bottom: 20px;
}

.footer-links a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: #3498db;
}

.company-info {
    font-size: 0.9rem;
    color: #95a5a6;
    max-width: 800px;
    line-height: 1.8;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .nav-container {
        flex-direction: column;
        gap: 20px;
    }
    
    .nav-links {
        gap: 15px;
    }
}

@media (max-width: 768px) {
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .main-content {
        padding: 30px 20px;
    }
    
    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.5rem;
    }
    
    .nav-links a {
        font-size: 1rem;
        padding: 6px 8px;
    }
    
    .contact-info {
        font-size: 0.9rem;
    }
}
li.active a {
    background-color: #3498db;
}

.content-placeholder {
    width: 100%;
    height: 100%;
}

.content-placeholder iframe {
    width: 100%;
    height: 100%;
    border: none;
}