:root {
    --primary: #007acc;
    --primary-dark: #005ca8;
    --secondary: #6c5e94;
    --accent: #72acc0;
    --light-bg: #f9f9f9;
    --dark-text: #333;
    --light-text: #fff;
    --gray-text: #555;
    --light-gray: #f1f1f1;
    --white: #fff;
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Poppins', Arial, sans-serif;
    background-color: var(--light-bg);
    color: var(--dark-text);
    line-height: 1.6;
    overflow-x: hidden;
}

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

/* 导航栏样式改进 */
.nav {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    padding: 15px 0;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav a {
    color: var(--light-text);
    text-decoration: none;
    margin: 0 15px;
    font-size: 18px;
    font-weight: 500;
    transition: var(--transition);
    padding: 10px 15px;
    border-radius: var(--border-radius);
}

.nav a:hover {
    background-color: rgba(255, 255, 255, 0.2);
    text-decoration: none;
    transform: translateY(-2px);
}

/* 头部样式改进 */
.header {
    background-color: var(--white);
    text-align: center;
    padding: 60px 20px 40px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: -50px;
    right: -50px;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, var(--primary) 0%, transparent 70%);
    opacity: 0.1;
    z-index: 0;
}

.header::after {
    content: '';
    position: absolute;
    bottom: -80px;
    left: -80px;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, var(--secondary) 0%, transparent 70%);
    opacity: 0.1;
    z-index: 0;
}

.header-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
}

.header img {
    max-width: 200px;
    margin-bottom: 20px;
    filter: drop-shadow(0 5px 15px rgba(0, 0, 0, 0.1));
    transition: var(--transition);
}

.header img:hover {
    transform: scale(1.05);
}

.header h2 {
    font-size: 36px;
    margin-bottom: 12px;
    color: var(--secondary);
    font-weight: 700;
    line-height: 1.2;
}

.header h4 {
    font-size: 18px;
    margin: 8px 0 20px;
    color: var(--accent);
    font-weight: 500;
    font-style: italic;
}

.header p {
    font-size: 18px;
    color: var(--gray-text);
    max-width: 600px;
    margin: 0 auto;
}

/* 主要内容区样式改进 */
.content {
    max-width: 800px;
    margin: 50px auto;
    padding: 40px;
    background-color: var(--white);
    border-radius: var(--border-radius);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
    line-height: 1.8;
    color: var(--gray-text);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.content::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 6px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
}

.content h4 {
    font-size: 24px;
    margin-bottom: 20px;
    color: var(--secondary);
    font-weight: 600;
    border-bottom: 2px solid var(--light-gray);
    padding-bottom: 10px;
}

.content p {
    font-size: 17px;
    margin-bottom: 20px;
}

/* 页脚样式改进 */
.footer {
    background: linear-gradient(135deg, #b4fdfd 0%, #e0f7ff 100%);
    text-align: center;
    padding: 40px 20px;
    font-size: 15px;
    color: var(--dark-text);
    box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.05);
}

.footer-links {
    margin: 25px 0;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
}

.footer-links a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 16px;
    transition: var(--transition);
    display: inline-block;
    padding: 8px 15px;
    border-radius: var(--border-radius);
}

.footer-links a:hover {
    background-color: rgba(0, 122, 204, 0.1);
    text-decoration: none;
    transform: translateY(-2px);
}

.footer p {
    margin: 15px 0;
    font-size: 14px;
    color: var(--gray-text);
}

.footer-bottom {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    color: var(--gray-text);
    font-size: 13px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header h2 {
        font-size: 28px;
    }
    
    .header h4 {
        font-size: 16px;
    }
    
    .header p {
        font-size: 16px;
    }
    
    .content {
        padding: 30px 20px;
    }
    
    .content h4 {
        font-size: 22px;
    }
    
    .nav a {
        margin: 0 10px;
        font-size: 16px;
    }
    
    .footer-links {
        flex-direction: column;
        align-items: center;
    }
    
    .footer-links a {
        margin-bottom: 8px;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 50px 15px 30px;
    }
    
    .header h2 {
        font-size: 24px;
    }
    
    .nav {
        padding: 10px 0;
    }
    
    .nav a {
        margin: 0 8px;
        font-size: 14px;
    }
}