/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
}

/* 导航栏样式 */
.main-nav {
    position: fixed;
    top: 0;
    width: 100%;
    height: 60px;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 40px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #0066cc;
}

/* 主要横幅区域样式 */
.hero-section {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.3)),
                url('../images/videodiff-product.jpg') no-repeat center center;
    background-size: cover;
    color: white;
    margin-top: 60px; /* 确保在导航栏下方 */
}

.hero-content h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2rem;
    background: #0066cc;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    margin-top: 2rem;
    transition: background 0.3s;
}

.cta-button:hover {
    background: #0052a3;
}

/* 产品展示区样式 */
.products-section {
    padding: 5rem 2rem;
    background: #f5f5f5;
}

.product-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.product-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s;
}

.product-card:hover {
    transform: translateY(-5px);
}

.product-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.product-card h3 {
    padding: 1rem;
    font-size: 1.5rem;
}

.product-card p {
    padding: 0 1rem;
    color: #666;
}

.learn-more {
    display: block;
    padding: 1rem;
    text-align: center;
    text-decoration: none;
    color: #0066cc;
    font-weight: 500;
}

/* 页脚样式 */
footer {
    background: #333;
    color: white;
    padding: 3rem 2rem;
}

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

.footer-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.footer-column h4 {
    margin-bottom: 1rem;
}

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

.footer-column a {
    color: #ccc;
    text-decoration: none;
    display: block;
    padding: 0.5rem 0;
    transition: color 0.3s;
}

.footer-column a:hover {
    color: white;
}

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

    .hero-content h1 {
        font-size: 2.5rem;
    }
}

/* 下拉菜单基础样式 */
.dropdown {
    position: relative;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 160px;
    background: #fff;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    border-radius: 4px;
    padding: 8px 0;
    z-index: 1000;
}

/* 悬浮显示效果 */
.dropdown:hover .dropdown-menu {
    display: block;
    animation: fadeIn 0.3s ease;
}

/* 下拉菜单项样式 */
.dropdown-menu li {
    padding: 8px 16px;
    font-size: 14px;
    position: relative;
}

.dropdown-menu a {
    color: #333;
    text-decoration: none;
    transition: color 0.2s;
}

.dropdown-menu a:hover {
    color: #007bff;
}