/* ============================================================
   宽城区麟商破晓互联网零售中心 - 官网样式
   主题：柔和粉蓝色 (Soft Powder-Blue) + 白色
   ============================================================ */

/* ---------- CSS 变量 ---------- */
:root {
    /* 核心配色 */
    --primary: #5b9bd5;
    --primary-hover: #4a8bc4;
    --primary-light: #e0edf6;
    --primary-lighter: #f1f7fc;
    --primary-soft: #f8fbfd;

    /* 文本色阶 */
    --ink-1: #1e293b;          /* 主文本 */
    --ink-2: #475569;          /* 次级文本 */
    --ink-3: #94a3b8;          /* 弱文本 */

    /* 背景与表面 */
    --bg: #ffffff;
    --surface: #ffffff;
    --surface-2: #f4f9fc;

    /* 边框与分割 */
    --border: #e0edf6;
    --border-strong: #c9dbea;

    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;

    /* 阴影 */
    --shadow-1: 0 1px 2px rgba(30, 41, 59, 0.04), 0 1px 1px rgba(30, 41, 59, 0.02);
    --shadow-2: 0 4px 12px -2px rgba(91, 155, 213, 0.08), 0 2px 4px rgba(30, 41, 59, 0.04);
    --shadow-3: 0 8px 24px -8px rgba(30, 41, 59, 0.10);
    --shadow-hover: 0 12px 28px -12px rgba(91, 155, 213, 0.25);

    /* 布局 */
    --container-max: 1152px;
    --header-h: 72px;

    /* 字体 */
    --font-sans: Inter, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;

    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-base: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg);
    color: var(--ink-1);
    line-height: 1.6;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

main {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--ink-1);
}

p {
    color: var(--ink-2);
}

a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-fast);
}

ul, ol {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
    color: inherit;
}

img, svg {
    display: block;
    max-width: 100%;
}

svg {
    flex-shrink: 0;
}

/* ---------- 通用容器 ---------- */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 64px 0;
}

.section-alt {
    background-color: var(--surface-2);
}

/* ---------- 通用区块头部 ---------- */
.section-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 40px;
}

.section-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background-color: var(--primary);
    color: #ffffff;
    box-shadow: 0 4px 10px rgba(91, 155, 213, 0.2);
    flex-shrink: 0;
}

.section-title {
    font-size: 24px;
    font-weight: 600;
    color: var(--ink-1);
}

/* ============================================================
   Header 导航栏
   ============================================================ */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid transparent;
    transition: all var(--transition-base);
}

.site-header.scrolled {
    border-bottom-color: var(--border);
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-1);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-h);
    gap: 16px;
}

.brand-link {
    display: flex;
    align-items: center;
    gap: 10px;
    transition: opacity var(--transition-fast);
}

.brand-link:hover {
    opacity: 0.85;
}

.brand-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--primary) 0%, #7cb4e8 100%);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(91, 155, 213, 0.3);
}

.brand-name {
    font-size: 16px;
    font-weight: 600;
    color: var(--ink-1);
    letter-spacing: -0.01em;
}

/* Navigation */
.site-nav {
    align-items: center;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 4px;
}

.nav-link {
    display: inline-flex;
    align-items: center;
    padding: 8px 16px;
    border-radius: var(--radius-md);
    font-size: 14px;
    color: var(--ink-3);
    font-weight: 500;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    color: var(--ink-1);
    background-color: var(--primary-lighter);
}

.nav-link.active {
    color: var(--primary);
    background-color: var(--primary-lighter);
}

/* Mobile Menu Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    padding: 8px;
    border-radius: var(--radius-sm);
    transition: background-color var(--transition-fast);
}

.nav-toggle:hover {
    background-color: var(--primary-lighter);
}

.nav-toggle-bar {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--ink-2);
    border-radius: 1px;
    transition: all var(--transition-base);
    margin: 0 auto;
}

.nav-toggle.open .nav-toggle-bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle.open .nav-toggle-bar:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.nav-toggle.open .nav-toggle-bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ============================================================
   Hero 区域
   ============================================================ */
.hero-section {
    position: relative;
    background: linear-gradient(180deg, var(--primary-lighter) 0%, #ffffff 100%);
    padding: 80px 0 100px;
    overflow: hidden;
}

/* Hero 装饰背景 */
.hero-bg-decoration {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 0;
}

.hero-blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.4;
    animation: blobFloat 8s ease-in-out infinite;
}

.hero-blob-1 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--primary) 0%, transparent 70%);
    top: -100px;
    right: -80px;
}

.hero-blob-2 {
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, #a8d0f0 0%, transparent 70%);
    bottom: -80px;
    left: -60px;
    animation-delay: -4s;
}

@keyframes blobFloat {
    0%, 100% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(-20px, -30px) scale(1.08); }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 780px;
    margin: 0 auto;
}

.hero-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    border-radius: 999px;
    background-color: rgba(91, 155, 213, 0.1);
    color: var(--primary);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.05em;
    margin-bottom: 20px;
    backdrop-filter: blur(8px);
}

.hero-tag-dot {
    display: inline-block;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(91, 155, 213, 0.15);
    animation: pulseDot 2s ease-in-out infinite;
}

@keyframes pulseDot {
    0%, 100% { box-shadow: 0 0 0 4px rgba(91, 155, 213, 0.15); }
    50% { box-shadow: 0 0 0 8px rgba(91, 155, 213, 0.05); }
}

.hero-title {
    font-size: clamp(28px, 5vw, 48px);
    font-weight: 700;
    color: var(--ink-1);
    letter-spacing: -0.02em;
    margin-bottom: 20px;
    line-height: 1.25;
}

.hero-subtitle {
    font-size: clamp(15px, 2vw, 18px);
    color: var(--ink-2);
    max-width: 600px;
    margin: 0 auto 36px;
    line-height: 1.75;
}

.hero-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 56px;
}

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-size: 15px;
    font-weight: 500;
    transition: all var(--transition-base);
    cursor: pointer;
    white-space: nowrap;
}

.btn-primary {
    background-color: var(--primary);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(91, 155, 213, 0.3);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(91, 155, 213, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-outline {
    background-color: #ffffff;
    color: var(--primary);
    border: 1px solid var(--primary-light);
}

.btn-outline:hover {
    background-color: var(--primary-lighter);
    border-color: var(--primary);
    transform: translateY(-2px);
}

/* Hero Stats 数据统计 */
.hero-stats {
    display: inline-flex;
    align-items: center;
    gap: 0;
    padding: 20px 32px;
    background-color: #ffffff;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-2);
    flex-wrap: wrap;
    justify-content: center;
}

.stat-item {
    padding: 0 28px;
    text-align: center;
}

.stat-divider {
    width: 1px;
    height: 40px;
    background-color: var(--border);
}

.stat-number {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary);
    line-height: 1.1;
    letter-spacing: -0.02em;
    font-variant-numeric: tabular-nums;
}

.stat-label {
    font-size: 13px;
    color: var(--ink-3);
    margin-top: 4px;
}

/* Scroll indicator */
.scroll-indicator {
    position: absolute;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    opacity: 0.7;
    z-index: 1;
}

.scroll-mouse {
    display: inline-block;
    width: 24px;
    height: 38px;
    border: 2px solid var(--primary);
    border-radius: 12px;
    position: relative;
}

.scroll-wheel {
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 3px;
    height: 8px;
    background-color: var(--primary);
    border-radius: 2px;
    animation: scrollWheel 1.8s ease-in-out infinite;
}

@keyframes scrollWheel {
    0% { transform: translate(-50%, 0); opacity: 1; }
    80%, 100% { transform: translate(-50%, 14px); opacity: 0; }
}

.scroll-text {
    font-size: 12px;
    color: var(--ink-3);
    letter-spacing: 0.05em;
}

/* 渐入动画 */
.fade-in-up {
    opacity: 0;
    transform: translateY(24px);
    animation: fadeInUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.fade-in-up.delay-1 { animation-delay: 0.1s; }
.fade-in-up.delay-2 { animation-delay: 0.2s; }
.fade-in-up.delay-3 { animation-delay: 0.3s; }
.fade-in-up.delay-4 { animation-delay: 0.45s; }

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

/* Reveal 滚动触发动画 */
.reveal {
    opacity: 0;
    transform: translateY(32px);
    transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================================
   经营范围 Business Scope
   ============================================================ */
.business-section {
    background-color: var(--bg);
}

.business-card {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow-1);
    transition: box-shadow var(--transition-base);
}

.business-card:hover {
    box-shadow: var(--shadow-2);
}

.business-intro {
    font-size: 16px;
    color: var(--ink-1);
    line-height: 1.8;
    margin-bottom: 32px;
}

/* 分类标签 */
.category-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 28px;
    padding: 6px;
    background-color: var(--primary-soft);
    border-radius: var(--radius-md);
    width: fit-content;
}

.tab-btn {
    padding: 8px 18px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    color: var(--ink-3);
    transition: all var(--transition-fast);
}

.tab-btn:hover {
    color: var(--ink-2);
}

.tab-btn.active {
    background-color: #ffffff;
    color: var(--primary);
    box-shadow: var(--shadow-1);
}

/* 经营范围条目网格 */
.scope-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px 32px;
}

.scope-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 10px 0;
    transition: all var(--transition-fast);
}

.scope-item.filtered-out {
    display: none;
}

.scope-icon-wrap {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    margin-top: 2px;
    border-radius: 7px;
    background-color: rgba(91, 155, 213, 0.1);
    color: var(--primary);
    transition: all var(--transition-base);
}

.scope-item:hover .scope-icon-wrap {
    background-color: var(--primary);
    color: #ffffff;
    transform: scale(1.1);
}

.scope-text {
    font-size: 15px;
    color: var(--ink-1);
    line-height: 1.55;
    padding-top: 3px;
}

/* 说明提示 */
.business-notice {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-top: 32px;
    padding: 16px 20px;
    background-color: var(--primary-lighter);
    border-radius: var(--radius-md);
    font-size: 14px;
    color: var(--ink-2);
    line-height: 1.7;
}

.business-notice svg {
    flex-shrink: 0;
    margin-top: 2px;
    color: var(--primary);
}

/* ============================================================
   服务优势 Advantages
   ============================================================ */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.advantage-card {
    position: relative;
    background-color: #ffffff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px 24px 28px;
    overflow: hidden;
    transition: all var(--transition-base);
}

.advantage-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), #a8d0f0);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-slow);
}

.advantage-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-light);
}

.advantage-card:hover::before {
    transform: scaleX(1);
}

.advantage-num {
    position: absolute;
    top: 16px;
    right: 20px;
    font-size: 36px;
    font-weight: 700;
    color: var(--primary-lighter);
    line-height: 1;
    letter-spacing: -0.03em;
    z-index: 0;
}

.advantage-icon {
    position: relative;
    z-index: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, rgba(91, 155, 213, 0.1) 0%, rgba(168, 208, 240, 0.1) 100%);
    color: var(--primary);
    margin-bottom: 20px;
    transition: all var(--transition-base);
}

.advantage-card:hover .advantage-icon {
    background: linear-gradient(135deg, var(--primary), #7cb4e8);
    color: #ffffff;
    transform: scale(1.05);
    box-shadow: 0 6px 16px rgba(91, 155, 213, 0.3);
}

.advantage-title {
    position: relative;
    z-index: 1;
    font-size: 18px;
    font-weight: 600;
    color: var(--ink-1);
    margin-bottom: 10px;
}

.advantage-desc {
    position: relative;
    z-index: 1;
    font-size: 14px;
    color: var(--ink-2);
    line-height: 1.75;
}

/* ---------- 核心能力矩阵（增加布局高度） ---------- */
.capabilities-block {
    margin-top: 48px;
    padding: 40px;
    background-color: #ffffff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-1);
}

.capabilities-header {
    margin-bottom: 28px;
    text-align: center;
}

.capabilities-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--ink-1);
    margin-bottom: 6px;
}

.capabilities-sub {
    font-size: 14px;
    color: var(--ink-3);
}

.capabilities-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px 20px;
}

.capability-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 16px 14px;
    border-radius: var(--radius-md);
    background-color: var(--primary-soft);
    transition: all var(--transition-base);
}

.capability-item:hover {
    background-color: var(--primary-lighter);
    transform: translateY(-2px);
    box-shadow: var(--shadow-2);
}

.capability-dot {
    flex-shrink: 0;
    width: 8px;
    height: 8px;
    margin-top: 7px;
    border-radius: 50%;
    background-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(91, 155, 213, 0.12);
}

.capability-body {
    min-width: 0;
}

.capability-name {
    font-size: 14px;
    font-weight: 600;
    color: var(--ink-1);
    margin-bottom: 2px;
    line-height: 1.4;
}

.capability-meta {
    font-size: 12px;
    color: var(--ink-3);
    line-height: 1.5;
}

/* ---------- CTA 横幅 ---------- */
.cta-banner {
    margin-top: 32px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--primary) 0%, #7cb4e8 100%);
    padding: 36px 44px;
    box-shadow: 0 12px 32px rgba(91, 155, 213, 0.25);
    position: relative;
    overflow: hidden;
}

.cta-banner::before,
.cta-banner::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.12);
    filter: blur(20px);
    pointer-events: none;
}

.cta-banner::before {
    width: 160px;
    height: 160px;
    top: -60px;
    right: 60px;
}

.cta-banner::after {
    width: 120px;
    height: 120px;
    bottom: -50px;
    left: 30px;
}

.cta-content {
    position: relative;
    z-index: 1;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    flex-wrap: wrap;
}

.cta-title {
    font-size: 20px;
    font-weight: 600;
    color: #ffffff;
    margin-bottom: 6px;
}

.cta-desc {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.9);
}

.cta-banner .btn-primary {
    background-color: #ffffff;
    color: var(--primary);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.cta-banner .btn-primary:hover {
    background-color: #f4f9fc;
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
    color: var(--primary-hover);
}

/* ============================================================
   Footer 页脚
   ============================================================ */
.site-footer {
    position: relative;
    background-color: var(--bg);
    border-top: 1px solid var(--border);
    padding: 48px 0 24px;
    margin-top: auto;
}

.footer-inner {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 32px;
    flex-wrap: wrap;
}

.footer-brand {
    flex: 1;
    min-width: 280px;
    max-width: 440px;
}

.footer-logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--primary) 0%, #7cb4e8 100%);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(91, 155, 213, 0.3);
    margin-bottom: 14px;
}

.footer-name {
    font-size: 15px;
    font-weight: 600;
    color: var(--ink-1);
    margin-bottom: 4px;
}

.footer-note {
    font-size: 13px;
    color: var(--ink-3);
    margin-bottom: 20px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 14px;
    color: var(--ink-2);
}

.contact-item svg {
    color: var(--primary);
    flex-shrink: 0;
}

/* 备案徽章 - 改为超链接容器，支持img优先+svg兜底 */
.footer-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    justify-content: flex-end;
}

.footer-badge-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 112px;
    min-height: 72px;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background-color: var(--surface);
    transition: all var(--transition-base);
    cursor: pointer;
    text-decoration: none;
}

.footer-badge-link:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-2);
    transform: translateY(-2px);
}

.badge-img {
    width: auto;
    height: 32px;
    max-width: 96px;
    object-fit: contain;
    margin-bottom: 6px;
    display: block;
}

.badge-placeholder {
    display: none; /* 图片正常加载时隐藏兜底SVG；只有onerror失败才显示 */
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 32px;
    color: var(--ink-3);
    opacity: 0.5;
    margin-bottom: 6px;
}

.badge-label {
    font-size: 12px;
    color: var(--ink-3);
    text-align: center;
}

/* 页脚底部 */
.footer-bottom {
    margin-top: 36px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    text-align: center;
}

.copyright {
    font-size: 13px;
    color: var(--ink-3);
}

.entity-type {
    font-size: 11px;
    color: var(--ink-3);
    opacity: 0.75;
    margin-top: 4px;
}

/* 回到顶部 */
.back-to-top {
    position: fixed;
    right: 24px;
    bottom: 32px;
    z-index: 90;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: #ffffff;
    border: 1px solid var(--border);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-2);
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: all var(--transition-base);
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background-color: var(--primary);
    color: #ffffff;
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(91, 155, 213, 0.35);
}

/* ============================================================
   响应式适配 Responsive
   ============================================================ */

/* 平板 < 1024px */
@media (max-width: 1024px) {
    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .capabilities-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .stat-item {
        padding: 0 20px;
    }
}

/* 平板 < 768px */
@media (max-width: 768px) {
    :root {
        --header-h: 64px;
    }

    .container {
        padding: 0 20px;
    }

    .section {
        padding: 48px 0;
    }

    /* Header & Mobile Menu */
    .brand-name {
        font-size: 14px;
    }

    .nav-toggle {
        display: flex;
    }

    .site-nav {
        position: absolute;
        top: var(--header-h);
        left: 0;
        right: 0;
        background-color: #ffffff;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-2);
        padding: 16px 24px;
        transform: translateY(-8px);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }

    .site-nav.open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-list {
        flex-direction: column;
        align-items: stretch;
        gap: 2px;
    }

    .nav-link {
        width: 100%;
        padding: 12px 14px;
        border-radius: var(--radius-sm);
    }

    .nav-link.active::after {
        left: 12px;
        bottom: 50%;
        transform: translateY(50%);
    }

    /* Hero */
    .hero-section {
        padding: 56px 0 80px;
    }

    .hero-title {
        font-size: 28px;
    }

    .hero-subtitle {
        font-size: 15px;
        margin-bottom: 28px;
    }

    .hero-actions {
        margin-bottom: 40px;
    }

    .hero-stats {
        padding: 16px 20px;
        gap: 16px;
        flex-direction: column;
    }

    .stat-divider {
        width: 40px;
        height: 1px;
    }

    .stat-item {
        padding: 0;
    }

    .stat-number {
        font-size: 26px;
    }

    .scroll-indicator {
        display: none;
    }

    /* Section header */
    .section-header {
        margin-bottom: 28px;
    }

    .section-title {
        font-size: 20px;
    }

    /* Business scope */
    .business-card {
        padding: 24px 20px;
    }

    .business-intro {
        font-size: 15px;
        margin-bottom: 24px;
    }

    .category-tabs {
        width: 100%;
        overflow-x: auto;
        flex-wrap: nowrap;
        padding: 4px;
    }

    .tab-btn {
        flex-shrink: 0;
        white-space: nowrap;
        padding: 7px 14px;
        font-size: 13px;
    }

    .scope-grid {
        grid-template-columns: 1fr;
        gap: 4px;
    }

    .scope-text {
        font-size: 14px;
    }

    .business-notice {
        font-size: 13px;
        padding: 14px 16px;
    }

    /* Advantages */
    .advantages-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .advantage-card {
        padding: 24px 20px;
    }

    .capabilities-block {
        padding: 24px 20px;
        margin-top: 32px;
    }

    .capabilities-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px 12px;
    }

    .capability-item {
        padding: 12px 10px;
    }

    .cta-banner {
        padding: 24px 22px;
        margin-top: 24px;
    }

    .cta-title {
        font-size: 17px;
    }

    .cta-desc {
        font-size: 13px;
        margin-bottom: 12px;
    }

    /* Footer */
    .site-footer {
        padding: 40px 0 20px;
    }

    .footer-inner {
        flex-direction: column;
        gap: 28px;
    }

    .footer-badges {
        justify-content: flex-start;
    }

    .footer-bottom {
        text-align: center;
    }

    .back-to-top {
        right: 16px;
        bottom: 24px;
        width: 40px;
        height: 40px;
    }
}

/* 小屏手机 < 480px */
@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .brand-logo {
        width: 32px;
        height: 32px;
        border-radius: 8px;
    }

    .brand-logo svg {
        width: 18px;
        height: 18px;
    }

    .brand-name {
        font-size: 13px;
        line-height: 1.3;
    }

    .hero-title {
        font-size: 24px;
    }

    .btn {
        padding: 11px 20px;
        font-size: 14px;
    }

    .section-icon {
        width: 36px;
        height: 36px;
    }

    .section-title {
        font-size: 18px;
    }

    .business-card {
        padding: 20px 16px;
    }

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

    .cta-banner .btn-primary {
        width: 100%;
    }

    .footer-badge-link {
        min-width: 96px;
        min-height: 68px;
        padding: 10px 8px;
    }
}

/* 大屏优化 > 1440px */
@media (min-width: 1440px) {
    :root {
        --container-max: 1280px;
    }
}

/* 深色模式兜底 (目前不启用但保留变量兼容) */
@media (prefers-color-scheme: dark) {
    /* 当前保持浅色风格，不强制切换深色 */
}

/* 减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .hero-blob {
        animation: none !important;
    }

    .reveal {
        opacity: 1 !important;
        transform: none !important;
    }

    .fade-in-up {
        opacity: 1 !important;
        transform: none !important;
        animation: none !important;
    }
}