/* 全局重置+核心配色（科技黑+活力青+浅灰）+ SEO基础 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Inter", "Microsoft Yahei", sans-serif;
    scroll-behavior: smooth; /* 顺滑滚动，提升用户体验 */
}

:root {
    --primary: #121212;    /* 主色-科技黑（极简、专业） */
    --accent: #00C896;     /* 强调色-活力青（科技、运动） */
    --light: #F8F9FA;      /* 浅灰背景 */
    --gray: #6C757D;       /* 中性灰文本 */
    --dark-gray: #343A40;  /* 深灰文本 */
    --shadow: 0 4px 16px rgba(0, 200, 150, 0.08); /* 青调科技阴影 */
    --hover-shadow: 0 8px 24px rgba(0, 200, 150, 0.15); /* 悬浮增强阴影 */
    --gradient: linear-gradient(135deg, #00C896, #00A884); /* 活力青渐变 */
}

body {
    background-color: var(--light);
    color: var(--dark-gray);
    line-height: 1.7;
}

/* 通用容器（极简窄边距，适配科技风）+ SEO语义化 */
.container {
    width: 88%;
    max-width: 1300px;
    margin: 0 auto;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

/* 导航架构差异化：PC侧边固定+移动端顶部折叠 */
.nav-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 80px;
    background-color: var(--primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    padding: 30px 0;
    z-index: 999;
}

/* 移动端导航（差异化折叠式） */
.mobile-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--primary);
    padding: 15px 0;
    z-index: 999;
}

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

.mobile-logo {
    color: var(--accent);
    font-size: 24px;
    font-weight: 700;
}

.mobile-menu-btn {
    color: var(--light);
    font-size: 22px;
    cursor: pointer;
}

.mobile-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: var(--primary);
    padding: 20px 0;
}

.mobile-menu li {
    padding: 10px 20px;
}

.mobile-menu li a {
    color: var(--light);
    font-size: 16px;
}

/* PC端侧边导航（差异化极简图标式） */
.side-logo {
    color: var(--accent);
    font-size: 28px;
    font-weight: 800;
    writing-mode: vertical-rl;
    text-orientation: mixed;
}

.side-menu {
    display: flex;
    flex-direction: column;
    gap: 40px;
    align-items: center;
}

.side-menu li a {
    color: var(--light);
    font-size: 18px;
    opacity: 0.7;
    transition: all 0.3s ease;
}

.side-menu li a:hover, .side-menu li a.active {
    opacity: 1;
    color: var(--accent);
}

/* 主内容区（差异化：偏移侧边导航宽度） */
.main-content-wrap {
    margin-left: 80px;
    min-height: 100vh;
}

/* Banner区域（差异化：全屏科技感静态图+极简文案） */
.banner {
    height: 90vh;
    background: url("https://tse-mm.bing.com/th?q=B体育 智能体育用品 科技场景") center/cover no-repeat;
    position: relative;
    display: flex;
    align-items: center;
    padding-left: 80px;
}

.banner::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(18, 18, 18, 0.7);
}

.banner-content {
    position: relative;
    z-index: 2;
    max-width: 600px;
}

.banner-content h1 {
    font-size: 48px;
    color: var(--light);
    margin-bottom: 20px;
    line-height: 1.2;
}

.banner-content h1 span {
    color: var(--accent);
}

.banner-content p {
    font-size: 18px;
    color: var(--light);
    opacity: 0.9;
    margin-bottom: 30px;
}

.banner-btn {
    display: inline-block;
    padding: 12px 30px;
    background: var(--gradient);
    color: var(--light);
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.banner-btn:hover {
    transform: translateY(-3px);
    box-shadow: var(--hover-shadow);
}

/* 核心模块（差异化：卡片式流布局+科技感边框） */
.section {
    padding: 80px 0;
}

.section-title {
    font-size: 32px;
    color: var(--primary);
    margin-bottom: 50px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: "";
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--accent);
}

/* 首页核心优势（差异化：网格卡片+微粒子hover） */
.advantage-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.advantage-card {
    background-color: #FFFFFF;
    padding: 35px 25px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    border: 1px solid transparent;
    transition: all 0.4s ease;
}

.advantage-card:hover {
    border-color: var(--accent);
    box-shadow: var(--hover-shadow);
    transform: translateY(-5px);
}

.advantage-card h3 {
    color: var(--primary);
    font-size: 20px;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.advantage-card h3 i {
    color: var(--accent);
    font-size: 22px;
}

.advantage-card p {
    color: var(--gray);
    font-size: 15px;
    line-height: 1.7;
}

/* 产品中心（差异化：场景化分类+极简卡片） */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.product-card {
    background-color: #FFFFFF;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.4s ease;
}

.product-card:hover {
    box-shadow: var(--hover-shadow);
}

.product-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: all 0.4s ease;
}

.product-card:hover img {
    transform: scale(1.05);
}

.product-card .product-info {
    padding: 20px;
}

.product-card .product-info h3 {
    color: var(--primary);
    font-size: 18px;
    margin-bottom: 10px;
}

.product-card .product-info p {
    color: var(--gray);
    font-size: 14px;
    line-height: 1.6;
}

/* 新闻资讯（差异化：极简列表+青调标签） */
.news-list {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.news-item {
    background-color: #FFFFFF;
    padding: 25px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    border-left: 4px solid transparent;
    transition: all 0.3s ease;
}

.news-item:hover {
    border-left-color: var(--accent);
    box-shadow: var(--hover-shadow);
}

.news-item .news-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.news-item .news-title {
    color: var(--primary);
    font-size: 18px;
    font-weight: 600;
}

.news-item .news-date {
    color: var(--accent);
    font-size: 14px;
}

.news-item .news-desc {
    color: var(--gray);
    font-size: 15px;
    line-height: 1.7;
}

/* 案例展示（差异化：大图+极简文案叠加） */
.case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
    gap: 30px;
}

.case-card {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    height: 400px;
    box-shadow: var(--shadow);
}

.case-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: all 0.5s ease;
}

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

.case-card .case-info {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 30px;
    background: linear-gradient(to top, var(--primary), transparent);
    color: var(--light);
}

.case-card .case-info h3 {
    font-size: 20px;
    margin-bottom: 10px;
}

.case-card .case-info p {
    opacity: 0.9;
    font-size: 14px;
    line-height: 1.6;
}

/* 联系我们（差异化：分栏极简+渐变按钮） */
.contact-wrap {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.contact-info {
    background-color: var(--primary);
    color: var(--light);
    padding: 40px;
    border-radius: 12px;
}

.contact-info h3 {
    font-size: 22px;
    margin-bottom: 30px;
    color: var(--accent);
}

.contact-info .info-item {
    margin-bottom: 25px;
}

.contact-info .info-item p {
    display: flex;
    align-items: center;
    gap: 10px;
    opacity: 0.9;
    font-size: 15px;
}

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

.contact-form input, .contact-form textarea {
    padding: 15px;
    border: 1px solid #E9ECEF;
    border-radius: 8px;
    font-size: 15px;
    color: var(--dark-gray);
    transition: all 0.3s ease;
}

.contact-form input:focus, .contact-form textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(0, 200, 150, 0.1);
}

.contact-form button {
    padding: 15px;
    background: var(--gradient);
    color: var(--light);
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

/* 底部（差异化：极简黑底+青调文字） */
.footer {
    background-color: var(--primary);
    color: var(--light);
    padding: 60px 0 20px;
    margin-left: 80px;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 14px;
    opacity: 0.7;
}

/* 响应式适配（差异化：移动端侧边导航隐藏，顶部导航显示） */
@media (max-width: 992px) {
    .nav-wrapper {
        display: none;
    }
    .main-content-wrap, .footer {
        margin-left: 0;
    }
    .mobile-nav {
        display: block;
    }
    .banner {
        padding-left: 20px;
        height: 70vh;
    }
    .banner-content h1 {
        font-size: 36px;
    }
    .contact-wrap {
        grid-template-columns: 1fr;
    }
    .case-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .advantage-grid {
        grid-template-columns: 1fr;
    }
    .product-grid {
        grid-template-columns: 1fr;
    }
    .banner-content h1 {
        font-size: 28px;
    }
    .section {
        padding: 50px 0;
    }
}