/* 全局重置+核心配色（体育用品风：赛事蓝+活力橙+运动灰）+ SEO语义化基础 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Lato", "Microsoft Yahei", sans-serif;
}

:root {
    --primary: #0066CC;    /* 主色-赛事蓝（专业、信任） */
    --accent: #FF7A00;     /* 强调色-活力橙（运动、吸睛） */
    --gray: #F0F2F5;       /* 运动灰（背景） */
    --dark: #333333;       /* 深文本色 */
    --light-text: #666666; /* 浅文本色 */
    --shadow: 0 6px 18px rgba(0, 102, 204, 0.12); /* 蓝调运动阴影 */
    --hover-shadow: 0 10px 25px rgba(255, 122, 0, 0.18); /* 橙调悬浮阴影 */
    --skew-angle: 2deg;    /* 动感斜切角度 */
}

body {
    background-color: var(--gray);
    color: var(--dark);
    line-height: 1.8;
    overflow-x: hidden;
}

/* 通用容器（宽屏适配，贴合体育赛事视觉比例）+ SEO语义化 */
.container {
    width: 90%;
    max-width: 1400px;
    margin: 0 auto;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.4s ease;
}

ul {
    list-style: none;
}

/* 头部导航（差异化：运动悬浮导航+蓝橙渐变）+ SEO友好（语义化标签） */
.header {
    background-color: var(--white);
    border-bottom: 1px solid rgba(0, 102, 204, 0.1);
    padding: 18px 0;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 999;
    box-shadow: var(--shadow);
}

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

.logo {
    font-size: 28px;
    font-weight: 800;
    letter-spacing: 1px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo span {
    font-size: 20px;
    font-weight: 600;
}

.nav-menu {
    display: flex;
    gap: 38px;
}

.nav-menu li a {
    font-size: 16px;
    font-weight: 500;
    position: relative;
    text-transform: capitalize;
}

/* 导航hover特效（差异化：运动轨迹下划线） */
.nav-menu li a::after {
    content: "";
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 3px;
    background: var(--accent);
    border-radius: 3px;
    transition: width 0.3s ease-in-out;
}

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

/* 横幅区域（差异化：运动场景全屏背景+动感蒙版）+ SEO（图片alt优化） */
.banner {
    margin-top: 80px;
    height: 75vh;
    background: url("https://tse-mm.bing.com/th?q=b体育 体育用品 赛事场景") center/cover no-repeat;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.banner::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(0, 102, 204, 0.7), rgba(255, 122, 0, 0.6));
}

.banner-content {
    position: relative;
    z-index: 2;
    max-width: 950px;
    padding: 0 20px;
}

.banner-content h1 {
    font-size: 46px;
    color: #FFFFFF;
    margin-bottom: 25px;
    text-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.banner-content p {
    font-size: 20px;
    color: #FFFFFF;
    opacity: 0.95;
    line-height: 1.7;
}

/* 核心内容区（差异化：动感斜切卡片+模块化排版）+ SEO（语义化section标签） */
.main-content {
    padding: 85px 0;
}

.section-title {
    font-size: 32px;
    color: var(--primary);
    margin-bottom: 50px;
    position: relative;
    padding-left: 15px;
}

.section-title::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 30px;
    background: var(--accent);
    border-radius: 3px;
}

/* 首页内容布局（差异化：非对称运动感分栏）+ SEO（关键词自然分布） */
.home-content {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 50px;
    align-items: center;
}

.text-box p {
    color: var(--light-text);
    margin-bottom: 22px;
    font-size: 17px;
    line-height: 1.9;
}

.text-box p strong {
    color: var(--primary);
    font-weight: 600;
}

.img-box {
    position: relative;
    transform: skewX(var(--skew-angle));
    box-shadow: var(--hover-shadow);
    border-radius: 8px;
    overflow: hidden;
}

.img-box img {
    width: 100%;
    transform: skewX(calc(-1 * var(--skew-angle)));
    transition: transform 0.6s ease;
}

.img-box:hover img {
    transform: skewX(calc(-1 * var(--skew-angle))) scale(1.05);
}

/* 产品/体育用品展示（差异化：运动模块卡片+橙蓝渐变边框）+ SEO（产品标题关键词） */
.product-section {
    padding: 70px 0;
    background-color: #FFFFFF;
    border-radius: 16px;
    margin: 50px 0;
    box-shadow: var(--shadow);
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 35px;
}

.product-card {
    background-color: #FFFFFF;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.5s ease;
    border: 2px solid transparent;
    background-clip: padding-box;
    position: relative;
}

.product-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border-radius: 10px;
    padding: 2px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.4s ease;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--hover-shadow);
}

.product-card:hover::before {
    opacity: 1;
}

.product-card img {
    width: 100%;
    height: 220px;
    object-fit: cover;
}

.product-card .card-info {
    padding: 28px;
}

.product-card .card-info h3 {
    font-size: 20px;
    color: var(--primary);
    margin-bottom: 12px;
}

.product-card .card-info p {
    color: var(--light-text);
    font-size: 15px;
    line-height: 1.7;
}

/* 案例展示（差异化：赛事合作场景卡片+动态缩放）+ SEO（案例标题含关键词） */
.case-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(480px, 1fr));
    gap: 40px;
}

.case-card {
    position: relative;
    border-radius: 10px;
    overflow: hidden;
    height: 420px;
    box-shadow: var(--shadow);
    transition: all 0.6s ease;
}

.case-card:hover {
    transform: scale(1.02);
    box-shadow: var(--hover-shadow);
}

.case-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.8s ease;
}

.case-card:hover img {
    transform: scale(1.1);
}

.case-card .case-info {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 35px;
    background: linear-gradient(to top, rgba(0, 102, 204, 0.9), transparent);
    color: #FFFFFF;
}

.case-card .case-info h3 {
    font-size: 22px;
    margin-bottom: 12px;
}

.case-card .case-info p {
    opacity: 0.9;
    line-height: 1.7;
}

/* 新闻资讯（差异化：运动资讯卡片+橙蓝标签）+ SEO（新闻标题含关键词） */
.news-list {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.news-item {
    padding: 30px;
    background-color: #FFFFFF;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: all 0.4s ease;
    border-left: 5px solid var(--primary);
}

.news-item:hover {
    border-left-color: var(--accent);
    transform: translateX(5px);
}

.news-item .news-title {
    font-size: 20px;
    color: var(--primary);
    margin-bottom: 10px;
}

.news-item .news-date {
    font-size: 14px;
    color: var(--accent);
    margin-bottom: 15px;
    display: inline-block;
    background: rgba(255, 122, 0, 0.1);
    padding: 4px 12px;
    border-radius: 20px;
}

.news-item .news-desc {
    color: var(--light-text);
    line-height: 1.7;
}

/* 联系我们（差异化：运动风表单+蓝橙渐变按钮）+ SEO（联系信息语义化） */
.contact-wrap {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 45px;
}

.contact-info {
    background: linear-gradient(135deg, var(--primary), #0077DD);
    color: #FFFFFF;
    padding: 40px;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.contact-info .info-item {
    margin-bottom: 35px;
}

.contact-info .info-item h3 {
    font-size: 20px;
    margin-bottom: 15px;
    color: var(--accent);
}

.contact-info .info-item p {
    opacity: 0.9;
    line-height: 1.8;
}

.contact-form form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-form input, .contact-form textarea {
    padding: 16px 20px;
    background-color: #FFFFFF;
    border: 1px solid #E0E0E0;
    border-radius: 8px;
    font-size: 16px;
    color: var(--dark);
    transition: all 0.4s ease;
}

.contact-form input:focus, .contact-form textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.contact-form button {
    padding: 16px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    color: #FFFFFF;
    border: none;
    border-radius: 8px;
    font-size: 17px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.4s ease;
}

.contact-form button:hover {
    transform: translateY(-3px);
    box-shadow: var(--hover-shadow);
}

/* 底部（差异化：运动风版权栏+蓝橙分隔线）+ SEO（版权信息+站点地图简化） */
.footer {
    background-color: var(--dark);
    color: #FFFFFF;
    padding: 70px 0 30px;
    margin-top: 80px;
    border-top: 5px solid var(--accent);
}

.footer-bottom {
    text-align: center;
    padding-top: 35px;
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 15px;
    opacity: 0.8;
}

/* 响应式适配（差异化：运动场景移动端适配）+ SEO（移动端友好） */
@media (max-width: 1200px) {
    .home-content {
        grid-template-columns: 1fr;
    }
    .case-list {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 992px) {
    .contact-wrap {
        grid-template-columns: 1fr;
    }
    .banner-content h1 {
        font-size: 38px;
    }
    .product-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-wrap {
        flex-direction: column;
        gap: 18px;
    }
    .nav-menu {
        gap: 25px;
    }
    .banner {
        height: 60vh;
    }
    .section-title {
        font-size: 26px;
    }
}