:root {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --text-color: #333;
    --background-color: #f4f4f4;
    --white: #ffffff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 头部样式 */
.main-header {
    background-color: var(--white);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    padding: 15px 0;
}

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

.logo a {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
}

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

.main-nav ul li {
    margin-left: 20px;
}

.main-nav ul li a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.main-nav ul li a:hover {
    color: var(--primary-color);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.mobile-menu-toggle span {
    height: 3px;
    width: 25px;
    background-color: var(--text-color);
    margin: 3px 0;
    transition: 0.4s;
}

/* 主内容区 */
.main-content {
    flex: 1;
    padding: 30px 0;
}

/* 底部样式 */
.main-footer {
    background-color: #2c3e50;
    color: var(--white);
    padding: 40px 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
}

.footer-section {
    flex: 1;
    margin-right: 20px;
}

.footer-section h4 {
    margin-bottom: 15px;
    color: var(--white);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: var(--white);
}

.social-icons {
    display: flex;
}

.social-icon {
    color: rgba(255, 255, 255, 0.7);
    margin-right: 15px;
    font-size: 1.5rem;
    transition: color 0.3s ease;
}

.social-icon:hover {
    color: var(--white);
}

.copyright {
    text-align: center;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .main-nav {
        display: none;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .footer-content {
        flex-direction: column;
    }

    .footer-section {
        margin-bottom: 20px;
    }
}