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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: #f5f5f5;
    padding: 40px 100px;
    margin: 0;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
.main-nav {
    background-color: #fff;
    border-bottom: 1px solid #e0e0e0;
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin: -40px -100px 0 -100px;
    padding-left: 100px;
    padding-right: 100px;
}

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

.nav-brand .logo {
    font-size: 24px;
    font-weight: 700;
    color: #000;
    text-decoration: none;
    letter-spacing: 2px;
    transition: color 0.3s ease;
}

.nav-brand .logo:hover {
    color: #666;
}

.nav-links {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-link {
    color: #666;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #000;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #000;
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

/* 响应式导航 */
@media (max-width: 768px) {
    .main-nav {
        margin: -40px -30px 0 -30px;
        padding-left: 30px;
        padding-right: 30px;
    }
    
    .main-nav .container {
        flex-direction: column;
        gap: 15px;
    }
    
    .nav-links {
        gap: 20px;
    }
    
    .nav-link {
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .main-nav {
        margin: -40px -20px 0 -20px;
        padding-left: 20px;
        padding-right: 20px;
    }
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 50px;
    padding: 40px 0;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.header h1 {
    font-size: 30px;
    font-weight: 600;
}

.header a {
    color: #666;
    text-decoration: underline;
    font-size: 14px;
    transition: color 0.3s ease;
}

.header a:hover {
    color: #000;
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 35px;
    margin-bottom: 40px;
}

@media (max-width: 1200px) {
    .products-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 768px) {
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 25px;
    }
}

@media (max-width: 768px) {
    body {
        padding: 40px 30px;
    }
}

@media (max-width: 480px) {
    body {
        padding: 40px 20px;
    }
    
    .products-grid {
        grid-template-columns: 1fr;
    }
}

.product-card {
    background: white;
    border-radius: 8px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
}

.product-image {
    width: 100%;
    height: 200px;
    background: #f9f9f9;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.product-image.no-image {
    background: #e0e0e0;
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.product-info {
    padding: 15px;
}

.product-brand {
    font-size: 12px;
    color: #999;
    margin-bottom: 8px;
}

.product-name {
    font-size: 13px;
    font-weight: 600;
    color: #000;
    line-height: 1.3;
}

.product-name:hover {
    color: #333;
}

.footer {
    margin-top: 60px;
    padding: 15px 0;
    background-color: #f5f5f5;
    border-top: 1px solid #e0e0e0;
}

.footer-text {
    font-size: 12px;
    color: #999;
    text-align: center;
    line-height: 1.5;
    margin: 0;
}

/* AdSense广告位样式 */
.ad-container {
    margin: 30px 0;
    text-align: center;
    background-color: #f9f9f9;
    border: 2px dashed #ddd;
    border-radius: 8px;
    padding: 20px;
}

.ad-header {
    margin-top: 0;
    margin-bottom: 40px;
}

.ad-middle {
    margin: 40px 0;
}

.ad-footer {
    margin: 40px 0 20px 0;
    background-color: #f5f5f5;
}

.ad-placeholder {
    display: inline-block;
    padding: 20px;
    background-color: #fff;
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.ad-placeholder p {
    margin: 0 0 8px 0;
    font-size: 14px;
    font-weight: 600;
    color: #333;
}

.ad-placeholder small {
    font-size: 11px;
    color: #666;
    font-style: italic;
}

/* 页面内容样式 */
.page-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 0;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-top: 40px;
    margin-bottom: 40px;
}

.page-content h1 {
    font-size: 32px;
    font-weight: 600;
    color: #000;
    margin-bottom: 10px;
    text-align: center;
    padding: 0 20px;
}

.page-content h2 {
    font-size: 20px;
    font-weight: 600;
    color: #333;
    margin: 30px 0 15px 0;
    padding: 0 20px;
}

.page-content p {
    font-size: 14px;
    line-height: 1.6;
    color: #666;
    margin-bottom: 15px;
    padding: 0 20px;
}

.page-content section {
    margin-bottom: 30px;
}

.last-updated {
    font-style: italic;
    color: #999;
    text-align: center;
    margin-bottom: 30px;
}

/* 响应式广告位 */
@media (max-width: 768px) {
    .ad-container {
        margin: 20px 0;
        padding: 15px;
    }
    
    .ad-placeholder {
        padding: 15px;
    }
    
    .ad-placeholder p {
        font-size: 12px;
    }
    
    .ad-placeholder small {
        font-size: 10px;
    }
    
    .page-content {
        margin: 20px 0;
        padding: 20px 0;
    }
    
    .page-content h1 {
        font-size: 24px;
    }
    
    .page-content h2 {
        font-size: 18px;
    }
}