/* 全局重置+基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft Yahei", Arial, sans-serif;
}
body {
    color: #333;
    background: #f9f9f9;
    line-height: 1.6;
}
a {
    text-decoration: none;
    color: #2d8cf0;
    transition: all 0.3s;
}
a:hover {
    color: #1c69c0;
}
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}
ul {
    list-style: none;
}
.btn {
    display: inline-block;
    padding: 8px 18px;
    background: #2d8cf0;
    color: #fff;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 14px;
}
.btn:hover {
    background: #1c69c0;
}

/* 头部导航 */
.header {
    background: #fff;
    border-bottom: 1px solid #eee;
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 999;
}
.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo {
    font-size: 22px;
    font-weight: bold;
    color: #2d8cf0;
}
.nav ul {
    display: flex;
    gap: 25px;
}
.nav a {
    color: #333;
    font-size: 15px;
}
.nav a.active, .nav a:hover {
    color: #2d8cf0;
    border-bottom: 2px solid #2d8cf0;
}

/* 移动端适配 */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 10px;
    }
    .nav ul {
        gap: 12px;
    }
}

/* 横幅 */
.banner {
    background: #fff;
    padding: 60px 0;
    text-align: center;
}
.banner h1 {
    font-size: 32px;
    margin-bottom: 15px;
    color: #333;
}
.banner p {
    font-size: 16px;
    color: #666;
    max-width: 700px;
    margin: 0 auto;
}

/* 品牌分类标签 */
.brand-tabs {
    background: #fff;
    padding: 20px 0;
    border-bottom: 1px solid #eee;
}
.brand-tabs .container {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: center;
}
.brand-tabs .tab {
    padding: 8px 20px;
    background: #f5f5f5;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s;
}
.brand-tabs .tab.active {
    background: #2d8cf0;
    color: #fff;
}
.brand-tabs .tab:hover {
    background: #e8e8e8;
}
.brand-tabs .tab.active:hover {
    background: #1c69c0;
}

/* 产品列表 */
.product-section {
    padding: 40px 0 60px;
}
.section-title {
    text-align: center;
    margin-bottom: 40px;
}
.section-title h2 {
    font-size: 26px;
    color: #333;
    position: relative;
    display: inline-block;
}
.section-title h2::after {
    content: "";
    display: block;
    width: 50px;
    height: 3px;
    background: #2d8cf0;
    margin: 10px auto;
}
.product-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
}
.product-card {
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    transition: transform 0.3s;
}
.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}
.product-img {
    width: 100%;
    height: 200px;
    overflow: hidden;
}
.product-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}
.product-card:hover .product-img img {
    transform: scale(1.05);
}
.product-info {
    padding: 20px;
}
.product-info h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: #333;
}
.product-info .brand-tag {
    display: inline-block;
    padding: 3px 8px;
    background: #e8f4ff;
    color: #2d8cf0;
    font-size: 12px;
    border-radius: 4px;
    margin-bottom: 10px;
}
.product-info .params {
    font-size: 14px;
    color: #666;
    margin-bottom: 15px;
    line-height: 1.8;
}
.product-info .params span {
    display: block;
}
.product-info .features {
    font-size: 14px;
    color: #666;
    margin-bottom: 20px;
}
.product-info .features strong {
    color: #333;
}

/* 选购指南 */
.buy-guide {
    background: #fff;
    padding: 60px 0;
}
.guide-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 30px;
}
.guide-item {
    padding: 20px;
    border-left: 4px solid #2d8cf0;
    background: #f8f9fa;
    border-radius: 4px;
}
.guide-item h3 {
    font-size: 18px;
    margin-bottom: 15px;
    color: #333;
}
.guide-item p {
    font-size: 14px;
    color: #666;
    line-height: 1.7;
}

/* 底部 */
.footer {
    background: #333;
    color: #ccc;
    padding: 40px 0 20px;
    margin-top: 40px;
}
.footer .container {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    justify-content: space-between;
}
.footer .col {
    flex: 1;
    min-width: 200px;
}
.footer .col h3 {
    font-size: 16px;
    color: #fff;
    margin-bottom: 20px;
}
.footer .col ul li {
    margin-bottom: 10px;
    font-size: 14px;
}
.footer .col a {
    color: #ccc;
}
.footer .col a:hover {
    color: #2d8cf0;
}
.footer .copyright {
    text-align: center;
    padding-top: 30px;
    margin-top: 20px;
    border-top: 1px solid #444;
    font-size: 13px;
}