/* 全局样式 */
* {
 margin: 0;
 padding: 0;
 box-sizing: border-box;
}

body {
 font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
 line-height: 1.6;
 color: #333;
 background: #f5f5f5;
}

/* 导航栏 */
header {
 background: #2c3e50;
 padding: 1rem 0;
 position: sticky;
 top: 0;
 z-index: 1000;
 box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.nav-container {
 max-width: 1200px;
 margin: 0 auto;
 padding: 0 2rem;
 display: flex;
 justify-content: space-between;
 align-items: center;
}

.logo {
 color: white;
 font-size: 1.5rem;
 font-weight: bold;
 text-decoration: none;
}

.nav-menu {
 display: flex;
 list-style: none;
 gap: 2rem;
 align-items: center;
}

.nav-menu a {
 color: white;
 text-decoration: none;
 padding: 0.5rem 1rem;
 transition: color 0.3s;
}

.nav-menu a:hover {
 color: #3498db;
}

/* 下拉菜单 */
.dropdown {
 position: relative;
}

.dropdown-menu {
 display: none;
 position: absolute;
 background: white;
 min-width: 200px;
 box-shadow: 0 8px 16px rgba(0,0,0,0.1);
 border-radius: 4px;
 padding: 0.5rem 0;
 top: 100%;
 left: 0;
}

.dropdown:hover .dropdown-menu {
 display: block;
}

.dropdown-menu a {
 color: #333 !important;
 display: block;
 padding: 0.75rem 1rem;
}

.dropdown-menu a:hover {
 background: #f5f5f5;
 color: #3498db !important;
}

.dropdown-divider {
 height: 1px;
 background: #eee;
 margin: 0.5rem 0;
}

/* Hero 区域 */
.hero {
 background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
 color: white;
 text-align: center;
 padding: 4rem 2rem;
}

.hero h1 {
 font-size: 3rem;
 margin-bottom: 1rem;
}

.tagline {
 font-size: 1.5rem;
 margin-bottom: 2rem;
 opacity: 0.9;
}

.cta-button {
 display: inline-block;
 background: white;
 color: #667eea;
 padding: 1rem 2rem;
 border-radius: 5px;
 text-decoration: none;
 font-weight: bold;
 transition: transform 0.3s;
}

.cta-button:hover {
 transform: translateY(-2px);
}

/* 产品卡片 */
.products-preview {
 max-width: 1200px;
 margin: 4rem auto;
 padding: 0 2rem;
}

.products-preview h2 {
 text-align: center;
 font-size: 2.5rem;
 margin-bottom: 3rem;
 color: #2c3e50;
}

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

.card {
 background: white;
 padding: 2rem;
 border-radius: 8px;
 box-shadow: 0 2px 10px rgba(0,0,0,0.1);
 transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
 transform: translateY(-5px);
 box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.card h3 {
 color: #2c3e50;
 margin-bottom: 1rem;
 font-size: 1.5rem;
}

.card p {
 color: #666;
 margin-bottom: 1.5rem;
}

.card a {
 color: #3498db;
 text-decoration: none;
 font-weight: bold;
}

.card a:hover {
 text-decoration: underline;
}

/* 页脚 */
footer {
 background: #2c3e50;
 color: white;
 padding: 2rem;
 margin-top: 4rem;
}

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

.footer-content p {
 margin: 0.5rem 0;
}

.footer-links a {
 color: #3498db;
 text-decoration: none;
 margin: 0 0.5rem;
}

.footer-links a:hover {
 text-decoration: underline;
}

/* 响应式 */
@media (max-width: 768px) {
 .nav-menu {
 flex-direction: column;
 gap: 1rem;
 }
 
 .hero h1 {
 font-size: 2rem;
 }
 
 .tagline {
 font-size: 1.2rem;
 }
}