/* ================================================================
 * 天津中美家具 - 全新UI设计系统 v2.0
 * 现代简约商务风 | 蓝灰色调 | 移动优先响应式
 * SEO/GEO优化 | 多端自适应
 * ================================================================ */

/* ==================== CSS Variables ==================== */
:root {
    /* 主色调 - 深蓝灰 */
    --c-primary: #1e3a5f;
    --c-primary-light: #2c5282;
    --c-primary-lighter: #3182ce;
    --c-accent: #3182ce;
    --c-accent-light: #63b3ed;

    /* 中性色 */
    --c-text: #2d3748;
    --c-text-secondary: #4a5568;
    --c-text-muted: #718096;
    --c-border: #e2e8f0;
    --c-bg: #ffffff;
    --c-bg-alt: #f7fafc;
    --c-bg-dark: #1a202c;

    /* 功能色 */
    --c-success: #38a169;
    --c-warning: #d69e2e;
    --c-danger: #e53e3e;

    /* 间距 */
    --space-xs: 0.5rem;
    --space-sm: 0.75rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* 字体 */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "Microsoft YaHei", sans-serif;
    --fs-base: 16px;
    --fs-sm: 0.875rem;
    --fs-lg: 1.125rem;
    --fs-xl: 1.25rem;
    --fs-2xl: 1.5rem;
    --fs-3xl: 2rem;

    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;

    /* 阴影 */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);

    /* 布局 */
    --container-max: 1200px;
    --header-h: 72px;
    --transition: 0.3s ease;
}

/* ==================== Reset & Base ==================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: var(--fs-base); -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    color: var(--c-text);
    background: var(--c-bg);
    line-height: 1.6;
    font-size: var(--fs-base);
    overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }

a { color: var(--c-accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--c-primary); }

ul, ol { list-style: none; }

h1, h2, h3, h4, h5, h6 { font-weight: 600; line-height: 1.3; color: var(--c-text); }

/* ==================== Layout ==================== */
.container { max-width: var(--container-max); margin: 0 auto; padding: 0 var(--space-md); }

.section { padding: var(--space-3xl) 0; }
.section--alt { background: var(--c-bg-alt); }
.section--dark { background: var(--c-primary); color: #fff; }
.section--dark h2, .section--dark h3, .section--dark h4 { color: #fff; }

.section-head { text-align: center; margin-bottom: var(--space-2xl); }
.section-head h2 { font-size: var(--fs-2xl); color: var(--c-primary); margin-bottom: var(--space-xs); }
.section-head h2 strong { color: var(--c-accent); }
.section-head p { color: var(--c-text-muted); font-size: var(--fs-sm); }

.d-flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.justify-between { justify-content: space-between; }
.align-center { align-items: center; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-2 { margin-top: var(--space-sm); }
.mt-4 { margin-top: var(--space-lg); }
.mb-2 { margin-bottom: var(--space-sm); }
.mb-4 { margin-bottom: var(--space-lg); }
.hidden { display: none !important; }

/* ==================== Grid System ==================== */
.grid { display: grid; gap: var(--space-lg); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ==================== Header ==================== */
.site-header {
    position: sticky; top: 0; z-index: 1000;
    background: #fff;
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition);
}
.site-header.scrolled { box-shadow: var(--shadow-md); }

.header-top {
    background: var(--c-primary);
    color: rgba(255,255,255,0.85);
    font-size: var(--fs-sm);
    padding: 6px 0;
}
.header-top .container { display: flex; justify-content: space-between; align-items: center; }
.header-top a { color: rgba(255,255,255,0.85); }
.header-top a:hover { color: #fff; }

.header-main {
    display: flex; align-items: center; justify-content: space-between;
    height: var(--header-h);
    padding: 0 var(--space-md);
    max-width: var(--container-max); margin: 0 auto;
}

.header-logo { display: flex; align-items: center; gap: var(--space-md); }
.header-logo img { max-height: 48px; width: auto; }
.header-logo .logo-text h1 { font-size: var(--fs-lg); color: var(--c-primary); }
.header-logo .logo-text p { font-size: var(--fs-sm); color: var(--c-text-muted); }

.header-contact { display: flex; align-items: center; gap: var(--space-lg); }
.header-contact .tel { display: flex; align-items: center; gap: var(--space-sm); }
.header-contact .tel-icon {
    width: 40px; height: 40px; border-radius: 50%;
    background: var(--c-bg-alt); display: flex; align-items: center; justify-content: center;
    font-size: 20px; color: var(--c-accent);
}
.header-contact .tel-info span { display: block; font-size: 12px; color: var(--c-text-muted); }
.header-contact .tel-info strong { font-size: var(--fs-lg); color: var(--c-primary); }

/* ==================== Navigation ==================== */
.nav-bar { background: var(--c-primary); }
.nav-bar .container { display: flex; align-items: center; justify-content: space-between; }
.nav-list { display: flex; gap: 0; }
.nav-list > li { position: relative; }
.nav-list > li > a {
    display: block; padding: 14px 24px;
    color: rgba(255,255,255,0.9); font-size: var(--fs-base);
    transition: all var(--transition);
    border-bottom: 3px solid transparent;
}
.nav-list > li > a:hover, .nav-list > li.active > a {
    color: #fff; background: rgba(255,255,255,0.1);
    border-bottom-color: var(--c-accent-light);
}

/* 下拉菜单 */
.nav-sub {
    position: absolute; top: 100%; left: 0;
    min-width: 180px; background: #fff;
    box-shadow: var(--shadow-md);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    opacity: 0; visibility: hidden; transform: translateY(10px);
    transition: all var(--transition);
    z-index: 100;
}
.nav-list > li:hover .nav-sub { opacity: 1; visibility: visible; transform: translateY(0); }
.nav-sub li a {
    display: block; padding: 10px 20px;
    color: var(--c-text); font-size: var(--fs-sm);
    border-bottom: 1px solid var(--c-border);
    transition: all var(--transition);
}
.nav-sub li a:hover { background: var(--c-bg-alt); color: var(--c-accent); padding-left: 26px; }

/* 移动端菜单按钮 */
.nav-toggle {
    display: none; background: none; border: none;
    font-size: 24px; color: #fff; cursor: pointer; padding: 8px;
}

/* ==================== Hero/Banner ==================== */
.hero { position: relative; overflow: hidden; }
.hero-slider { position: relative; }
.hero-slide {
    height: 480px; background-size: cover; background-position: center;
    position: relative;
}
.hero-slide::after {
    content: ''; position: absolute; inset: 0;
    background: linear-gradient(90deg, rgba(30,58,95,0.7) 0%, rgba(30,58,95,0.2) 100%);
}
.hero-slide-content {
    position: absolute; inset: 0; z-index: 2;
    display: flex; flex-direction: column; justify-content: center;
    max-width: var(--container-max); margin: 0 auto; padding: 0 var(--space-md);
}
.hero-slide-content h2 { color: #fff; font-size: 2.5rem; margin-bottom: var(--space-md); }
.hero-slide-content p { color: rgba(255,255,255,0.9); font-size: var(--fs-lg); max-width: 600px; }
.hero-slide-content .btn { margin-top: var(--space-xl); align-self: flex-start; }

.hero-dots {
    position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%);
    display: flex; gap: 8px; z-index: 3;
}
.hero-dots span {
    width: 10px; height: 10px; border-radius: 50%;
    background: rgba(255,255,255,0.5); cursor: pointer; transition: all var(--transition);
}
.hero-dots span.active { background: #fff; width: 30px; border-radius: 5px; }

/* ==================== Buttons ==================== */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: var(--space-sm);
    padding: 10px 28px; border-radius: var(--radius-md);
    font-size: var(--fs-base); font-weight: 500;
    transition: all var(--transition); cursor: pointer; border: none;
    text-decoration: none;
}
.btn-primary { background: var(--c-accent); color: #fff; }
.btn-primary:hover { background: var(--c-primary); color: #fff; transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn-outline { background: transparent; color: var(--c-accent); border: 2px solid var(--c-accent); }
.btn-outline:hover { background: var(--c-accent); color: #fff; }
.btn-light { background: rgba(255,255,255,0.15); color: #fff; border: 1px solid rgba(255,255,255,0.3); }
.btn-light:hover { background: rgba(255,255,255,0.25); color: #fff; }
.btn-lg { padding: 14px 36px; font-size: var(--fs-lg); }

/* ==================== Cards ==================== */
.card {
    background: #fff; border-radius: var(--radius-lg);
    overflow: hidden; box-shadow: var(--shadow-sm);
    transition: all var(--transition);
}
.card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.card-img { overflow: hidden; aspect-ratio: 4/3; background: var(--c-bg-alt); }
.card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease; }
.card:hover .card-img img { transform: scale(1.08); }
.card-body { padding: var(--space-md); }
.card-title { font-size: var(--fs-base); font-weight: 600; margin-bottom: var(--space-xs); }
.card-title a { color: var(--c-text); }
.card-title a:hover { color: var(--c-accent); }
.card-text { font-size: var(--fs-sm); color: var(--c-text-muted); line-height: 1.5; }

/* ==================== Features (优势) ==================== */
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-lg); }
.feature-card {
    text-align: center; padding: var(--space-xl) var(--space-md);
    background: #fff; border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm); transition: all var(--transition);
    border: 1px solid var(--c-border);
}
.feature-card:hover { box-shadow: var(--shadow-lg); border-color: var(--c-accent-light); transform: translateY(-4px); }
.feature-icon {
    width: 64px; height: 64px; margin: 0 auto var(--space-md);
    border-radius: 50%; background: var(--c-bg-alt);
    display: flex; align-items: center; justify-content: center;
    font-size: 28px; color: var(--c-accent);
}
.feature-card h3 { font-size: var(--fs-lg); margin-bottom: var(--space-sm); }
.feature-card p { font-size: var(--fs-sm); color: var(--c-text-muted); }

/* ==================== Product List ==================== */
.product-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-lg); }
.product-card { background: #fff; border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-sm); transition: all var(--transition); }
.product-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.product-card .img-wrap { overflow: hidden; aspect-ratio: 1; background: var(--c-bg-alt); display: flex; align-items: center; justify-content: center; padding: var(--space-sm); box-sizing: border-box; }
.product-card .img-wrap img { max-width: 100%; max-height: 100%; width: auto; height: auto; object-fit: contain; transition: transform 0.5s; }
.product-card:hover .img-wrap img { transform: scale(1.08); }
.product-card .info { padding: var(--space-sm) var(--space-md); }
.product-card .info h3 { font-size: var(--fs-base); font-weight: 500; }
.product-card .info h3 a { color: var(--c-text); }
.product-card .info h3 a:hover { color: var(--c-accent); }

/* 侧栏产品列表 */
.product-layout { display: grid; grid-template-columns: 240px 1fr; gap: var(--space-xl); }
.product-sidebar h3 {
    font-size: var(--fs-lg); color: #fff; background: var(--c-primary);
    padding: var(--space-md); border-radius: var(--radius-md) var(--radius-md) 0 0;
}
.product-sidebar ul { border: 1px solid var(--c-border); border-top: none; border-radius: 0 0 var(--radius-md) var(--radius-md); }
.product-sidebar ul li a {
    display: block; padding: 10px var(--space-md);
    color: var(--c-text-secondary); border-bottom: 1px solid var(--c-border);
    transition: all var(--transition);
}
.product-sidebar ul li:last-child a { border-bottom: none; }
.product-sidebar ul li a:hover, .product-sidebar ul li.active a { background: var(--c-bg-alt); color: var(--c-accent); padding-left: calc(var(--space-md) + 6px); }
.product-sidebar .sidebar-contact { margin-top: var(--space-lg); padding: var(--space-lg); background: var(--c-bg-alt); border-radius: var(--radius-md); }
.product-sidebar .sidebar-contact h4 { color: var(--c-primary); margin-bottom: var(--space-sm); }
.product-sidebar .sidebar-contact .tel { font-size: var(--fs-xl); font-weight: 700; color: var(--c-accent); }

/* ==================== Product Detail ==================== */
.product-detail { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-2xl); }
.product-gallery .main-img { border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-md); aspect-ratio: 1; background: var(--c-bg-alt); display: flex; align-items: center; justify-content: center; padding: var(--space-md); box-sizing: border-box; }
.product-gallery .main-img img { max-width: 100%; max-height: 100%; width: auto; height: auto; object-fit: contain; }
.product-gallery .thumbs { display: flex; gap: var(--space-sm); margin-top: var(--space-md); }
.product-gallery .thumbs .thumb { width: 80px; height: 80px; border-radius: var(--radius-sm); overflow: hidden; border: 2px solid var(--c-border); cursor: pointer; transition: border-color var(--transition); display: flex; align-items: center; justify-content: center; background: var(--c-bg-alt); }
.product-gallery .thumbs .thumb.active, .product-gallery .thumbs .thumb:hover { border-color: var(--c-accent); }
.product-gallery .thumbs .thumb img { max-width: 100%; max-height: 100%; width: auto; height: auto; object-fit: contain; }

.product-info h1 { font-size: var(--fs-2xl); color: var(--c-text); margin-bottom: var(--space-md); }
.product-info .price { font-size: var(--fs-2xl); color: var(--c-danger); font-weight: 700; margin-bottom: var(--space-md); }
.product-info .specs { margin-bottom: var(--space-lg); }
.product-info .specs dt { color: var(--c-text-muted); font-size: var(--fs-sm); padding: 6px 0; }
.product-info .specs dd { color: var(--c-text); font-size: var(--fs-base); padding: 6px 0; border-bottom: 1px solid var(--c-border); }
.product-info .actions { display: flex; gap: var(--space-md); margin-top: var(--space-lg); }

/* ==================== News List ==================== */
.news-list { display: flex; flex-direction: column; gap: var(--space-lg); }
.news-item {
    display: flex; gap: var(--space-lg); padding: var(--space-lg);
    background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-sm);
    transition: all var(--transition);
}
.news-item:hover { box-shadow: var(--shadow-md); }
.news-item .news-img { flex-shrink: 0; width: 200px; height: 140px; border-radius: var(--radius-md); overflow: hidden; }
.news-item .news-img img { width: 100%; height: 100%; object-fit: cover; }
.news-item .news-body { flex: 1; }
.news-item .news-body h3 { font-size: var(--fs-lg); margin-bottom: var(--space-sm); }
.news-item .news-body h3 a { color: var(--c-text); }
.news-item .news-body h3 a:hover { color: var(--c-accent); }
.news-item .news-body .news-meta { font-size: var(--fs-sm); color: var(--c-text-muted); margin-bottom: var(--space-sm); }
.news-item .news-body .news-meta span { margin-right: var(--space-md); }
.news-item .news-body p { font-size: var(--fs-sm); color: var(--c-text-secondary); line-height: 1.6; }

/* ==================== Article/Content ==================== */
.article { background: #fff; padding: var(--space-2xl); border-radius: var(--radius-lg); box-shadow: var(--shadow-sm); }
.article-header { border-bottom: 2px solid var(--c-border); padding-bottom: var(--space-lg); margin-bottom: var(--space-xl); }
.article-header h1 { font-size: var(--fs-2xl); color: var(--c-text); margin-bottom: var(--space-sm); }
.article-header .meta { font-size: var(--fs-sm); color: var(--c-text-muted); }
.article-header .meta span { margin-right: var(--space-lg); }
.article-body { font-size: var(--fs-base); line-height: 1.8; color: var(--c-text-secondary); }
.article-body p { margin-bottom: var(--space-md); }
.article-body img { max-width: 100%; height: auto; border-radius: var(--radius-md); margin: var(--space-md) 0; }
.article-body h2, .article-body h3 { margin: var(--space-xl) 0 var(--space-md); color: var(--c-primary); }

/* 文章上下篇 */
.article-nav { display: flex; justify-content: space-between; gap: var(--space-md); margin-top: var(--space-2xl); padding-top: var(--space-lg); border-top: 1px solid var(--c-border); }
.article-nav a { font-size: var(--fs-sm); color: var(--c-text-secondary); }
.article-nav a:hover { color: var(--c-accent); }

/* ==================== Breadcrumb ==================== */
.breadcrumb { background: var(--c-bg-alt); padding: var(--space-sm) 0; }
.breadcrumb ol { display: flex; flex-wrap: wrap; gap: var(--space-xs); align-items: center; font-size: var(--fs-sm); }
.breadcrumb ol li { display: flex; align-items: center; gap: var(--space-xs); }
.breadcrumb ol li::after { content: '/'; color: var(--c-text-muted); margin-left: var(--space-xs); }
.breadcrumb ol li:last-child::after { display: none; }
.breadcrumb ol li a { color: var(--c-text-muted); }
.breadcrumb ol li a:hover { color: var(--c-accent); }
.breadcrumb ol li.current { color: var(--c-text); }

/* ==================== Pagination ==================== */
.pagination { display: flex; justify-content: center; gap: var(--space-xs); margin-top: var(--space-2xl); }
.pagination a, .pagination span {
    display: inline-flex; align-items: center; justify-content: center;
    min-width: 40px; height: 40px; padding: 0 var(--space-sm);
    border: 1px solid var(--c-border); border-radius: var(--radius-sm);
    font-size: var(--fs-sm); color: var(--c-text-secondary);
    transition: all var(--transition);
}
.pagination a:hover { border-color: var(--c-accent); color: var(--c-accent); }
.pagination .active { background: var(--c-accent); color: #fff; border-color: var(--c-accent); }

/* ==================== Advantages Section ==================== */
.advantages-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-lg); }
.advantage-card {
    position: relative; background: #fff; border-radius: var(--radius-lg);
    overflow: hidden; box-shadow: var(--shadow-sm);
    transition: all var(--transition);
}
.advantage-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.advantage-card .adv-img { height: 200px; overflow: hidden; }
.advantage-card .adv-img img { width: 100%; height: 100%; object-fit: cover; }
.advantage-card .adv-body { padding: var(--space-md); }
.advantage-card .adv-body h3 { font-size: var(--fs-lg); color: var(--c-primary); margin-bottom: var(--space-sm); }
.advantage-card .adv-body p { font-size: var(--fs-sm); color: var(--c-text-muted); }
.advantage-card .adv-num { position: absolute; top: var(--space-sm); right: var(--space-sm); font-size: 3rem; font-weight: 800; color: rgba(49,130,206,0.15); }

/* ==================== Process/Flow ==================== */
.process-flow { display: flex; justify-content: space-between; align-items: flex-start; gap: var(--space-md); flex-wrap: wrap; }
.process-step { flex: 1; min-width: 120px; text-align: center; position: relative; }
.process-step .step-icon {
    width: 64px; height: 64px; margin: 0 auto var(--space-sm);
    border-radius: 50%; background: var(--c-primary); color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-size: 24px; font-weight: 700;
}
.process-step h4 { font-size: var(--fs-sm); color: var(--c-text); }
.process-step::after {
    content: ''; position: absolute; top: 32px; right: -50%;
    width: 100%; height: 2px; background: var(--c-border); z-index: -1;
}
.process-step:last-child::after { display: none; }

/* ==================== CTA Banner ==================== */
.cta-banner {
    background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-light) 100%);
    color: #fff; padding: var(--space-2xl) 0; text-align: center;
}
.cta-banner h2 { color: #fff; font-size: var(--fs-2xl); margin-bottom: var(--space-md); }
.cta-banner p { font-size: var(--fs-lg); margin-bottom: var(--space-lg); opacity: 0.9; }
.cta-banner .btn { margin: 0 var(--space-sm); }

/* ==================== About Section ==================== */

/* About hero banner */
.about-hero {
    background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-light) 100%);
    color: #fff;
    padding: var(--space-2xl) var(--space-xl);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-xl);
    position: relative;
    overflow: hidden;
}
.about-hero::after {
    content: '';
    position: absolute;
    right: -40px; top: -40px;
    width: 200px; height: 200px;
    border-radius: 50%;
    background: rgba(255,255,255,0.06);
}
.about-hero::before {
    content: '';
    position: absolute;
    right: 80px; bottom: -60px;
    width: 140px; height: 140px;
    border-radius: 50%;
    background: rgba(255,255,255,0.04);
}
.about-hero h1 { font-size: var(--fs-3xl); margin: 0 0 var(--space-sm); position: relative; z-index: 1; }
.about-hero p { font-size: var(--fs-lg); opacity: 0.9; margin: 0; position: relative; z-index: 1; }

/* About stats */
.about-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-md);
    margin-bottom: var(--space-2xl);
}
.about-stat-card {
    text-align: center;
    padding: var(--space-lg) var(--space-md);
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition), box-shadow var(--transition);
}
.about-stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}
.about-stat-card .stat-num {
    font-size: var(--fs-3xl);
    font-weight: 700;
    color: var(--c-primary);
    line-height: 1.2;
}
.about-stat-card .stat-label {
    font-size: var(--fs-sm);
    color: var(--c-text-muted);
    margin-top: var(--space-xs);
}

/* About intro */
.about-intro {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: var(--space-2xl);
    align-items: start;
    margin-bottom: var(--space-2xl);
}
.about-intro-img {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: var(--space-lg);
}
.about-intro-img img { width: 100%; height: auto; display: block; }
.about-intro-text .article-body { font-size: var(--fs-base); line-height: 1.8; color: var(--c-text-secondary); }
.about-intro-text .article-body p { margin-bottom: var(--space-md); }
.about-intro-text .article-body img { max-width: 100%; height: auto; border-radius: var(--radius-md); }

/* About advantages */
.about-advantages {
    margin-bottom: var(--space-2xl);
}
.about-advantages .section-head { margin-bottom: var(--space-xl); }
.advantage-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}
.ab-card {
    padding: var(--space-xl) var(--space-lg);
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border-top: 3px solid var(--c-primary);
    transition: transform var(--transition), box-shadow var(--transition);
}
.ab-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}
.ab-card .ac-icon {
    width: 52px; height: 52px;
    border-radius: 50%;
    background: var(--c-accent-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-md);
}
.ab-card .ac-icon svg { width: 26px; height: 26px; color: var(--c-primary); }
.ab-card h3 { font-size: var(--fs-lg); color: var(--c-text); margin: 0 0 var(--space-sm); }
.ab-card p { font-size: var(--fs-sm); color: var(--c-text-muted); line-height: 1.7; margin: 0; }

/* About timeline */
.about-timeline {
    margin-bottom: var(--space-2xl);
}
.about-timeline .section-head { margin-bottom: var(--space-xl); }
.timeline {
    position: relative;
    padding-left: 40px;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 12px; top: 8px; bottom: 8px;
    width: 2px;
    background: var(--c-border);
}
.timeline-item {
    position: relative;
    padding-bottom: var(--space-xl);
}
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
    content: '';
    position: absolute;
    left: -34px; top: 4px;
    width: 14px; height: 14px;
    border-radius: 50%;
    background: var(--c-primary);
    border: 3px solid #fff;
    box-shadow: 0 0 0 2px var(--c-primary);
}
.timeline-item .ti-year {
    font-size: var(--fs-lg);
    font-weight: 700;
    color: var(--c-primary);
    margin-bottom: var(--space-xs);
}
.timeline-item .ti-title {
    font-size: var(--fs-base);
    color: var(--c-text);
    font-weight: 600;
    margin-bottom: var(--space-xs);
}
.timeline-item .ti-desc {
    font-size: var(--fs-sm);
    color: var(--c-text-muted);
    line-height: 1.7;
}

/* About clients */
.about-clients {
    margin-bottom: var(--space-xl);
}
.about-clients .section-head { margin-bottom: var(--space-xl); }
.client-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--space-md);
}
.client-item {
    height: 80px;
    background: #fff;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--fs-sm);
    color: var(--c-text-muted);
    font-weight: 500;
    transition: all var(--transition);
}
.client-item:hover {
    color: var(--c-primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

/* ==================== Contact ==================== */

/* Contact hero banner */
.contact-hero {
    background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-light) 100%);
    color: #fff;
    padding: var(--space-2xl) var(--space-xl);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-xl);
    position: relative;
    overflow: hidden;
}
.contact-hero::after {
    content: '';
    position: absolute;
    right: -40px; top: -40px;
    width: 200px; height: 200px;
    border-radius: 50%;
    background: rgba(255,255,255,0.06);
}
.contact-hero::before {
    content: '';
    position: absolute;
    right: 80px; bottom: -60px;
    width: 140px; height: 140px;
    border-radius: 50%;
    background: rgba(255,255,255,0.04);
}
.contact-hero h1 { font-size: var(--fs-3xl); margin: 0 0 var(--space-sm); position: relative; z-index: 1; }
.contact-hero p { font-size: var(--fs-lg); opacity: 0.9; margin: 0; position: relative; z-index: 1; }

/* Contact method cards row */
.contact-methods {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
}
.contact-method-card {
    background: #fff;
    border: 1px solid var(--c-border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl) var(--space-lg);
    text-align: center;
    transition: all var(--transition);
    position: relative;
}
.contact-method-card:hover {
    border-color: var(--c-accent);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}
.contact-method-card .method-icon {
    width: 56px; height: 56px;
    margin: 0 auto var(--space-md);
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    background: var(--c-bg-alt);
    color: var(--c-accent);
}
.contact-method-card .method-icon svg { width: 28px; height: 28px; }
.contact-method-card .method-label { font-size: var(--fs-sm); color: var(--c-text-muted); margin-bottom: var(--space-xs); }
.contact-method-card .method-value { font-size: var(--fs-lg); color: var(--c-text); font-weight: 600; word-break: break-all; }
.contact-method-card .method-value a { color: var(--c-text); text-decoration: none; }

/* Contact main layout */
.contact-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: var(--space-2xl); align-items: start; }

/* Left column */
.contact-info .article-body { line-height: 1.8; color: var(--c-text-secondary); margin-bottom: var(--space-lg); }
.contact-info .article-body h2, .contact-info .article-body h3 { color: var(--c-primary); margin: var(--space-lg) 0 var(--space-sm); }

/* Contact detail list */
.contact-detail-list {
    list-style: none;
    padding: var(--space-lg);
    margin: 0;
    background: var(--c-bg-alt);
    border-radius: var(--radius-lg);
}
.contact-detail-list li {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
    padding: var(--space-sm) 0;
    border-bottom: 1px solid var(--c-border);
}
.contact-detail-list li:last-child { border-bottom: none; }
.contact-detail-list .dl-icon {
    width: 36px; height: 36px;
    border-radius: 50%;
    background: var(--c-primary);
    color: #fff;
    display: flex; align-items: center; justify-content: center;
    flex-shrink: 0;
    font-size: 14px;
}
.contact-detail-list .dl-icon svg { width: 18px; height: 18px; }
.contact-detail-list .dl-text { flex: 1; }
.contact-detail-list .dl-text .dl-label { font-size: var(--fs-sm); color: var(--c-text-muted); display: block; margin-bottom: 2px; }
.contact-detail-list .dl-text .dl-value { font-size: var(--fs-base); color: var(--c-text); font-weight: 500; }

/* QR code in detail list */
.contact-qr {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-top: var(--space-lg);
    padding: var(--space-md);
    background: #fff;
    border-radius: var(--radius-md);
    border: 1px solid var(--c-border);
}
.contact-qr img {
    width: 100px; height: 100px;
    object-fit: contain;
    border-radius: var(--radius-sm);
    flex-shrink: 0;
}
.contact-qr .qr-text { font-size: var(--fs-sm); color: var(--c-text-muted); line-height: 1.6; }
.contact-qr .qr-text strong { display: block; font-size: var(--fs-base); color: var(--c-text); margin-bottom: 4px; }

/* Right column: Form card */
.contact-form-wrap {
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
}
.contact-form-header {
    background: var(--c-primary);
    color: #fff;
    padding: var(--space-lg) var(--space-xl);
}
.contact-form-header h3 { font-size: var(--fs-xl); margin: 0; }
.contact-form-header p { font-size: var(--fs-sm); opacity: 0.85; margin: 4px 0 0; }
.contact-form-body { padding: var(--space-xl); }
.contact-form-body .form-group { margin-bottom: var(--space-md); }
.contact-form-body .form-group label { display: block; margin-bottom: var(--space-xs); font-size: var(--fs-sm); color: var(--c-text-secondary); font-weight: 500; }
.contact-form-body .form-group label span { color: var(--c-danger); margin-left: 2px; }
.contact-form-body .form-group input,
.contact-form-body .form-group textarea {
    width: 100%;
    padding: 12px var(--space-md);
    border: 1px solid var(--c-border);
    border-radius: var(--radius-sm);
    font-size: var(--fs-base);
    font-family: var(--font-sans);
    transition: border-color var(--transition);
    box-sizing: border-box;
}
.contact-form-body .form-group input:focus,
.contact-form-body .form-group textarea:focus {
    outline: none;
    border-color: var(--c-accent);
    box-shadow: 0 0 0 3px rgba(49,130,206,.10);
}
.contact-form-body .form-group textarea { min-height: 120px; resize: vertical; }
.contact-form-body .form-row { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-md); }
.contact-form-body .btn-submit {
    width: 100%;
    padding: 14px;
    background: var(--c-primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-size: var(--fs-lg);
    font-weight: 500;
    cursor: pointer;
    transition: background var(--transition);
    margin-top: var(--space-sm);
}
.contact-form-body .btn-submit:hover { background: var(--c-primary-light); }

/* Service promise strip */
.contact-promise {
    display: flex;
    justify-content: space-around;
    gap: var(--space-lg);
    margin-top: var(--space-xl);
    padding: var(--space-lg);
    background: var(--c-bg-alt);
    border-radius: var(--radius-lg);
    flex-wrap: wrap;
}
.contact-promise .promise-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}
.contact-promise .promise-item .pi-icon {
    width: 40px; height: 40px;
    border-radius: 50%;
    background: #fff;
    color: var(--c-accent);
    display: flex; align-items: center; justify-content: center;
    flex-shrink: 0;
}
.contact-promise .promise-item .pi-icon svg { width: 20px; height: 20px; }
.contact-promise .promise-item .pi-text { font-size: var(--fs-sm); color: var(--c-text-secondary); }
.contact-promise .promise-item .pi-text strong { display: block; font-size: var(--fs-base); color: var(--c-text); }

/* ==================== Search Bar ==================== */
.search-bar { display: flex; gap: var(--space-sm); }
.search-bar input {
    flex: 1; padding: 10px var(--space-md);
    border: 2px solid var(--c-border); border-radius: var(--radius-md);
    font-size: var(--fs-sm);
}
.search-bar input:focus { outline: none; border-color: var(--c-accent); }
.search-bar button {
    padding: 10px var(--space-lg); background: var(--c-accent); color: #fff;
    border: none; border-radius: var(--radius-md); cursor: pointer;
    font-size: var(--fs-sm); transition: background var(--transition);
}
.search-bar button:hover { background: var(--c-primary); }

/* 热门搜索 */
.hot-keywords { display: flex; align-items: center; gap: var(--space-sm); flex-wrap: wrap; }
.hot-keywords strong { color: var(--c-text-muted); font-size: var(--fs-sm); }
.hot-keywords a { font-size: var(--fs-sm); color: var(--c-text-secondary); padding: 4px 10px; background: var(--c-bg-alt); border-radius: var(--radius-sm); }
.hot-keywords a:hover { background: var(--c-accent); color: #fff; }

/* ==================== Tags ==================== */
.tags-cloud { display: flex; flex-wrap: wrap; gap: var(--space-sm); }
.tags-cloud a {
    padding: 6px 16px; background: var(--c-bg-alt); border-radius: var(--radius-sm);
    font-size: var(--fs-sm); color: var(--c-text-secondary);
    transition: all var(--transition);
}
.tags-cloud a:hover { background: var(--c-accent); color: #fff; }

/* ==================== Footer ==================== */
.site-footer { background: var(--c-bg-dark); color: rgba(255,255,255,0.7); padding: var(--space-3xl) 0 var(--space-lg); }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: var(--space-2xl); margin-bottom: var(--space-2xl); }
.footer-col h4 { color: #fff; font-size: var(--fs-base); margin-bottom: var(--space-md); }
.footer-col ul li { margin-bottom: var(--space-sm); }
.footer-col ul li a { color: rgba(255,255,255,0.6); font-size: var(--fs-sm); }
.footer-col ul li a:hover { color: #fff; }
.footer-col p { font-size: var(--fs-sm); line-height: 1.8; color: rgba(255,255,255,0.6); }
.footer-col .qr-code { width: 100px; height: 100px; border-radius: var(--radius-sm); overflow: hidden; }
.footer-col .qr-code img { width: 100%; height: 100%; object-fit: cover; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1); padding-top: var(--space-lg);
    display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: var(--space-md);
}
.footer-bottom p { font-size: var(--fs-sm); color: rgba(255,255,255,0.5); }
.footer-bottom a { color: rgba(255,255,255,0.5); font-size: var(--fs-sm); }
.footer-bottom a:hover { color: #fff; }
.footer-links a { margin-right: var(--space-md); }

/* ==================== Floating Sidebar ==================== */
.float-sidebar { position: fixed; right: 16px; bottom: 100px; z-index: 999; display: flex; flex-direction: column; gap: var(--space-xs); }
.float-sidebar .float-btn {
    width: 48px; height: 48px; border-radius: var(--radius-md);
    background: var(--c-primary); color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-size: 20px; cursor: pointer; transition: all var(--transition);
    box-shadow: var(--shadow-md); position: relative;
}
.float-sidebar .float-btn:hover { background: var(--c-accent); }
.float-sidebar .float-btn .tooltip {
    position: absolute; right: 56px; top: 50%; transform: translateY(-50%);
    background: var(--c-text); color: #fff; padding: 6px 12px;
    border-radius: var(--radius-sm); font-size: var(--fs-sm); white-space: nowrap;
    opacity: 0; visibility: hidden; transition: all var(--transition);
}
.float-sidebar .float-btn:hover .tooltip { opacity: 1; visibility: visible; }

/* ==================== Back to Top ==================== */
.back-top {
    position: fixed; right: 16px; bottom: 16px; z-index: 999;
    width: 48px; height: 48px; border-radius: 50%;
    background: var(--c-accent); color: #fff; border: none;
    display: flex; align-items: center; justify-content: center;
    font-size: 20px; cursor: pointer; opacity: 0; visibility: hidden;
    transition: all var(--transition); box-shadow: var(--shadow-md);
}
.back-top.visible { opacity: 1; visibility: visible; }
.back-top:hover { background: var(--c-primary); transform: translateY(-4px); }

/* ==================== Link List ==================== */
.friend-links { background: var(--c-bg-alt); padding: var(--space-lg) 0; }
.friend-links h4 { font-size: var(--fs-base); color: var(--c-primary); margin-bottom: var(--space-sm); }
.friend-links ul { display: flex; flex-wrap: wrap; gap: var(--space-sm); }
.friend-links ul li a { font-size: var(--fs-sm); color: var(--c-text-muted); }
.friend-links ul li a:hover { color: var(--c-accent); }

/* ==================== Animations ==================== */
@keyframes fadeInUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.fade-in-up { animation: fadeInUp 0.6s ease forwards; }
.fade-in { animation: fadeIn 0.6s ease forwards; }

/* ==================== Image Standardization ==================== */
img { max-width: 100%; height: auto; }
.content-body img, .article-body img { max-width: 100% !important; height: auto !important; border-radius: var(--radius-md); }

/* ==================== Responsive ==================== */

/* Tablet */
@media (max-width: 1024px) {
    :root { --fs-2xl: 1.75rem; --fs-3xl: 1.75rem; }
    .container { padding: 0 var(--space-lg); }
    .features-grid, .advantages-grid { grid-template-columns: repeat(2, 1fr); }
    .product-grid { grid-template-columns: repeat(3, 1fr); }
    .product-layout { grid-template-columns: 200px 1fr; gap: var(--space-lg); }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: var(--space-xl); }
    .hero-slide { height: 380px; }
    .hero-slide-content h2 { font-size: 2rem; }
}

/* Mobile */
@media (max-width: 768px) {
    :root { --header-h: 60px; --fs-2xl: 1.5rem; --fs-3xl: 1.5rem; --space-3xl: 2.5rem; }

    /* Header */
    .header-top { display: none; }
    .header-main { height: var(--header-h); }
    .header-logo .logo-text { display: none; }
    .header-contact { display: none; }

    /* Navigation */
    .nav-toggle { display: block; }
    .nav-bar .container { position: relative; }
    .nav-list {
        position: fixed; top: var(--header-h); left: 0; right: 0; bottom: 0;
        background: #fff; flex-direction: column;
        padding: var(--space-md); gap: 0;
        transform: translateX(100%); transition: transform var(--transition);
        overflow-y: auto; z-index: 999;
    }
    .nav-list.open { transform: translateX(0); }
    .nav-list > li > a { color: var(--c-text); padding: 14px var(--space-md); border-bottom: 1px solid var(--c-border); }
    .nav-list > li > a:hover, .nav-list > li.active > a { background: var(--c-bg-alt); color: var(--c-accent); }
    .nav-sub { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; min-width: auto; }
    .nav-sub li a { padding-left: var(--space-xl); }

    /* Hero */
    .hero-slide { height: 280px; }
    .hero-slide-content h2 { font-size: 1.5rem; }
    .hero-slide-content p { font-size: var(--fs-base); }
    .hero-slide-content .btn { padding: 8px 20px; font-size: var(--fs-sm); }

    /* Grids */
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .features-grid, .advantages-grid { grid-template-columns: 1fr; }
    .product-grid { grid-template-columns: repeat(2, 1fr); gap: var(--space-sm); }
    .product-card .info { padding: var(--space-xs) var(--space-sm); }
    .product-card .info h3 { font-size: var(--fs-sm); }

    /* Product Layout */
    .product-layout { grid-template-columns: 1fr; }
    .product-sidebar { order: 2; }

    /* Product Detail */
    .product-detail { grid-template-columns: 1fr; gap: var(--space-lg); }

    /* News */
    .news-item { flex-direction: column; gap: var(--space-sm); }
    .news-item .news-img { width: 100%; height: 180px; }

    /* About & Contact */
    .about-grid, .contact-grid { grid-template-columns: 1fr; gap: var(--space-lg); }
    .about-hero { padding: var(--space-xl) var(--space-md); }
    .about-hero h1 { font-size: var(--fs-xl); }
    .about-stats { grid-template-columns: repeat(2, 1fr); }
    .about-intro { grid-template-columns: 1fr; }
    .about-intro-img { position: static; }
    .advantage-grid { grid-template-columns: 1fr; }
    .client-grid { grid-template-columns: repeat(3, 1fr); }
    .contact-methods { grid-template-columns: 1fr; gap: var(--space-md); }
    .contact-form-body .form-row { grid-template-columns: 1fr; }
    .contact-promise { flex-direction: column; gap: var(--space-md); }
    .contact-hero { padding: var(--space-xl) var(--space-md); }
    .contact-hero h1 { font-size: var(--fs-xl); }

    /* Footer */
    .footer-grid { grid-template-columns: 1fr; gap: var(--space-lg); }
    .footer-bottom { flex-direction: column; text-align: center; }

    /* Process */
    .process-flow { flex-direction: column; align-items: center; }
    .process-step::after { display: none; }

    /* Article */
    .article { padding: var(--space-md); }
    .article-header h1 { font-size: var(--fs-xl); }

    /* Section spacing */
    .section { padding: var(--space-2xl) 0; }

    /* Floating elements */
    .float-sidebar { right: 8px; bottom: 80px; }
    .float-sidebar .float-btn { width: 40px; height: 40px; font-size: 16px; }
    .back-top { right: 8px; bottom: 8px; width: 40px; height: 40px; font-size: 16px; }
}

/* ==================== Message Page ==================== */
.message-page { padding: var(--space-xl) 0; }
.message-layout { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-xl); align-items: start; }
.message-info { background: var(--c-bg-alt); padding: var(--space-xl); border-radius: var(--radius-lg); }
.message-info h3 { font-size: var(--fs-xl); color: var(--c-primary); margin-bottom: var(--space-md); }
.message-info p { color: var(--c-text-secondary); line-height: 1.8; margin-bottom: var(--space-md); }
.message-info .info-item { display: flex; align-items: flex-start; gap: var(--space-sm); margin-bottom: var(--space-md); }
.message-info .info-item .icon { width: 40px; height: 40px; background: var(--c-primary); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 18px; flex-shrink: 0; }
.message-info .info-item .text span { display: block; font-size: var(--fs-sm); color: var(--c-text-muted); }
.message-info .info-item .text strong { font-size: var(--fs-base); color: var(--c-text); }
.message-form-wrap { background: #fff; padding: var(--space-xl); border-radius: var(--radius-lg); box-shadow: var(--shadow-sm); }
.message-form-wrap h3 { font-size: var(--fs-xl); color: var(--c-primary); margin-bottom: var(--space-lg); }
.message-form .form-group { margin-bottom: var(--space-md); }
.message-form .form-label { display: block; margin-bottom: var(--space-xs); font-size: var(--fs-sm); color: var(--c-text-secondary); font-weight: 500; }
.message-form .form-label span { color: var(--c-danger); margin-left: 2px; }
.message-form .form-control { width: 100%; padding: 10px var(--space-md); border: 1px solid var(--c-border); border-radius: var(--radius-sm); font-size: var(--fs-base); font-family: var(--font-sans); transition: border-color var(--transition); box-sizing: border-box; }
.message-form .form-control:focus { outline: none; border-color: var(--c-accent); box-shadow: 0 0 0 3px rgba(49,130,206,.12); }
.message-form textarea.form-control { min-height: 120px; resize: vertical; }
.message-form .form-actions { display: flex; gap: var(--space-sm); margin-top: var(--space-lg); }
.message-form .form-submit { padding: 10px var(--space-xl); background: var(--c-primary); color: #fff; border: none; border-radius: var(--radius-sm); font-size: var(--fs-base); cursor: pointer; transition: background var(--transition); }
.message-form .form-submit:hover { background: var(--c-primary-light); }
.message-form .form-button { padding: 10px var(--space-xl); background: var(--c-bg-alt); color: var(--c-text-secondary); border: 1px solid var(--c-border); border-radius: var(--radius-sm); font-size: var(--fs-base); cursor: pointer; transition: all var(--transition); }
.message-form .form-button:hover { background: var(--c-border); }

@media (max-width: 768px) {
    .message-layout { grid-template-columns: 1fr; }
}

/* Small Mobile */
@media (max-width: 480px) {
    .product-grid { grid-template-columns: 1fr; }
    .hero-slide-content h2 { font-size: 1.25rem; }
    .section-head h2 { font-size: var(--fs-xl); }
    .btn { padding: 8px 20px; font-size: var(--fs-sm); }
    .message-form .form-actions { flex-direction: column; }
    .message-form .form-submit, .message-form .form-button { width: 100%; text-align: center; }
}