/* 全局样式重置 */   
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Microsoft YaHei', sans-serif;   
}
   
body {
    background-color: #f5f5f5;
    color: #333;
    overflow-x: hidden;   
}
   
/* 头部样式 */   
header {
    background: linear-gradient(135deg, #1e5799 0%,#207cca 51%,#2989d8 100%);
    color: white;
    padding: 20px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: relative;
    z-index: 100;   
}
   
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;   
}
   
.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;   
}
   
.logo {
    font-size: 28px;
    font-weight: bold;   
}
   
nav ul {
    display: flex;
    list-style: none;   
}
   
nav ul li {
    margin-left: 30px;   
}
   
nav ul li a {
    color: white;
    text-decoration: none;
    font-size: 16px;
    transition: all 0.3s;   
}
   
nav ul li a:hover {
    color: #ffcc00;   
}
   
/* 视频背景区域 */   
.video-hero {
    position: relative;
    height: 100vh;
    min-height: 500px;
    overflow: hidden;   
}
   
.video-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 0;   
}
   
.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    z-index: 1;   
}
   
.hero-content {
    position: relative;
    z-index: 2;
    color: white;
    max-width: 600px;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;   
}
   
.hero-content h1 {
    font-size: 48px;
    margin-bottom: 20px;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.5);   
}
   
.hero-content p {
    font-size: 18px;
    margin-bottom: 30px;
    line-height: 1.6;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.5);   
}
   
/* 按钮样式 */   
.btn {
    display: inline-block;
    padding: 12px 30px;
    background-color: #ffcc00;
    color: #333;
    text-decoration: none;
    border-radius: 4px;
    font-weight: bold;
    transition: all 0.3s;
    border: none;
    cursor: pointer;   
}
   
.btn:hover {
    background-color: #ffdb4d;
    transform: translateY(-2px);   
}
   
/* 功能区域 */   
.features {
    padding: 80px 0;
    position: relative;
    z-index: 10;
    background-color: white;   
}
   
.section-title {
    text-align: center;
    margin-bottom: 50px;   
}
   
.section-title h2 {
    font-size: 36px;
    color: #333;   
}
   
.section-title p {
    color: #666;
    font-size: 18px;
    margin-top: 15px;   
}
   
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;   
}
   
.feature-card {
    background-color: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    text-align: center;
    transition: all 0.3s;
    border: 1px solid #eee;   
}
   
.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);   
}
   
.feature-icon {
    font-size: 50px;
    color: #2989d8;
    margin-bottom: 20px;   
}
   
.feature-card h3 {
    font-size: 22px;
    margin-bottom: 15px;   
}
   
.feature-card p {
    color: #666;
    line-height: 1.6;   
}
   
/* 页脚样式 */   
footer {
    background-color: #222;
    color: #aaa;
    padding: 50px 0 20px;   
}
   
.footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    margin-bottom: 40px;   
}
   
.footer-column h3 {
    color: white;
    margin-bottom: 20px;
    font-size: 18px;   
}
   
.footer-column ul {
    list-style: none;   
}
   
.footer-column ul li {
    margin-bottom: 10px;   
}
   
.footer-column ul li a {
    color: #aaa;
    text-decoration: none;
    transition: all 0.3s;   
}
   
.footer-column ul li a:hover {
    color: white;   
}
   
.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #444;
    font-size: 14px;   
}
   
/* 响应式设计 */   
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
    }
    
    nav ul {
        margin-top: 20px;
    }
    
    nav ul li {
        margin: 0 10px;
    }
    
    .hero-content h1 {
        font-size: 36px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }   
}