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

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --white: #ffffff;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
    --shadow-hover: 0 5px 20px rgba(0,0,0,0.15);
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.logo h1 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 600;
}

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

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--secondary-color);
    transition: width 0.3s;
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--secondary-color);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    margin: 3px 0;
    transition: 0.3s;
}

/* 轮播横幅 */
.hero {
    height: 500px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,154.7C960,171,1056,181,1152,165.3C1248,149,1344,107,1392,85.3L1440,64L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
}

.hero-slider {
    width: 100%;
    position: relative;
    z-index: 1;
}

.slide-content h2 {
    font-size: 3rem;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.slide-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease 0.2s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.btn-primary {
    display: inline-block;
    padding: 12px 30px;
    background: var(--accent-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 5px;
    transition: all 0.3s;
    font-weight: 500;
    animation: fadeInUp 1s ease 0.4s both;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    display: inline-block;
    padding: 12px 30px;
    background: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 5px;
    transition: all 0.3s;
    font-weight: 500;
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

/* 通用区块 */
section {
    padding: 4rem 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--primary-color);
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: var(--secondary-color);
}

/* 产品分类 */
.categories {
    background: var(--light-bg);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.category-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    cursor: pointer;
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.category-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.category-card h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.category-card p {
    color: #666;
}

/* 产品网格 */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.product-card {
    background: var(--white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    cursor: pointer;
}

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

.product-image {
    width: 100%;
    height: 250px;
    object-fit: cover;
    background: var(--light-bg);
    display: block;
    transition: opacity 0.3s ease;
    /* 确保图片按比例缩放 */
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
}

/* 图片加载优化 */
.product-image[loading="lazy"] {
    opacity: 0;
    transition: opacity 0.3s ease;
}

.product-image[loading="lazy"].loaded {
    opacity: 1;
}

.product-info {
    padding: 1.5rem;
}

.product-name {
    font-size: 1.2rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.product-category {
    color: #999;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.product-description {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
    line-height: 1.5;
}

.product-price {
    font-size: 1.5rem;
    color: var(--accent-color);
    font-weight: bold;
    margin-top: 0.5rem;
}

/* 优势区块 */
.advantages {
    background: var(--light-bg);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.advantage-item {
    text-align: center;
    padding: 2rem;
    background: var(--white);
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: all 0.3s;
}

.advantage-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.advantage-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.advantage-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

.advantage-item p {
    color: #666;
}

/* 页头 */
.page-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
    padding: 3rem 0;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* 筛选栏 */
.filter-bar {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 20px;
    border: 2px solid var(--secondary-color);
    background: var(--white);
    color: var(--secondary-color);
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1rem;
    font-weight: 500;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--secondary-color);
    color: var(--white);
    transform: translateY(-2px);
}

/* 页脚 */
.footer {
    background: var(--primary-color);
    color: var(--white);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--white);
}

.footer-section p {
    margin-bottom: 0.5rem;
    opacity: 0.8;
    line-height: 1.8;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--white);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.footer-section a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    opacity: 0.8;
}

.text-center {
    text-align: center;
    margin-top: 2rem;
}

/* 关于我们页面 */
.about-section {
    background: var(--light-bg);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    background: var(--white);
    padding: 3rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.about-content h2 {
    color: var(--primary-color);
    margin: 2rem 0 1rem;
    font-size: 1.8rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--secondary-color);
}

.about-content h2:first-child {
    margin-top: 0;
}

.about-content p {
    margin-bottom: 1.5rem;
    line-height: 1.8;
    color: #555;
}

.about-content ul {
    margin-left: 2rem;
    margin-bottom: 1.5rem;
}

.about-content li {
    margin-bottom: 0.8rem;
    line-height: 1.8;
    color: #555;
}

.about-content strong {
    color: var(--primary-color);
}

/* 公司信息表格 */
.company-info {
    margin: 2rem 0;
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 8px;
    border: 1px solid #e9ecef;
}

.info-table {
    width: 100%;
    border-collapse: collapse;
    margin: 0;
}

.info-table tr {
    border-bottom: 1px solid #dee2e6;
}

.info-table tr:last-child {
    border-bottom: none;
}

.info-table td {
    padding: 1rem;
    vertical-align: top;
    color: #555;
}

.info-table td:first-child {
    width: 180px;
    font-weight: 500;
    color: var(--primary-color);
}

.info-table td:last-child {
    color: #333;
}

/* 联系我们页面 */
.contact-section {
    background: var(--light-bg);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info,
.contact-form {
    background: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.contact-info h2,
.contact-form h2 {
    color: var(--primary-color);
    margin-bottom: 2rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--secondary-color);
}

.info-item {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid #eee;
}

.info-item:last-child {
    border-bottom: none;
}

.info-item h3 {
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.info-item p {
    color: #666;
    margin-bottom: 0.3rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    font-weight: 500;
}

.required {
    color: var(--accent-color);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--secondary-color);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--white);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .slide-content h2 {
        font-size: 2rem;
    }

    .slide-content p {
        font-size: 1rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .products-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 1rem;
    }

    .contact-content {
        grid-template-columns: 1fr;
    }

    .about-content {
        padding: 2rem 1.5rem;
    }
}

/* 退货退款政策页面 */
.policy-section {
    background: var(--light-bg);
    padding: 4rem 0;
}

.policy-content {
    max-width: 900px;
    margin: 0 auto;
    background: var(--white);
    padding: 3rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.policy-intro {
    background: #f0f7ff;
    padding: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid var(--secondary-color);
    margin-bottom: 2rem;
}

.policy-intro p {
    color: #555;
    line-height: 1.8;
    margin: 0;
}

.policy-item {
    margin-bottom: 2.5rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid #eee;
}

.policy-item:last-of-type {
    border-bottom: none;
}

.policy-item h2 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--secondary-color);
}

.policy-item p {
    color: #555;
    line-height: 1.8;
    margin-bottom: 1rem;
}

.policy-item ul,
.policy-item ol {
    margin-left: 2rem;
    margin-bottom: 1rem;
    color: #555;
}

.policy-item li {
    margin-bottom: 0.8rem;
    line-height: 1.8;
}

.policy-item li strong {
    color: var(--primary-color);
}

.policy-item ul ul {
    margin-top: 0.5rem;
    margin-bottom: 0.5rem;
}

.policy-item .note {
    background: #fff9e6;
    padding: 1rem;
    border-radius: 5px;
    border-left: 3px solid #ffc107;
    margin-top: 1rem;
    color: #856404;
    font-size: 0.95rem;
}

.policy-item .important {
    background: #ffe6e6;
    padding: 1rem;
    border-radius: 5px;
    border-left: 3px solid var(--accent-color);
    margin-top: 1rem;
    color: #721c24;
    font-weight: 500;
}

.policy-footer {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 2px solid var(--secondary-color);
    text-align: center;
    color: #666;
}

.policy-footer p {
    margin-bottom: 0.5rem;
}

@media (max-width: 480px) {
    .logo h1 {
        font-size: 1.2rem;
    }

    .hero {
        height: 400px;
    }

    .slide-content h2 {
        font-size: 1.5rem;
    }

    .category-grid,
    .advantages-grid {
        grid-template-columns: 1fr;
    }

    .products-grid {
        grid-template-columns: 1fr;
    }

    .policy-content {
        padding: 2rem 1.5rem;
    }

    .policy-item h2 {
        font-size: 1.3rem;
    }
}