/* ==========================================================================
   CELSKY 官网首页 PLAN B — styles.css  (V0.2 严格 1:1 复刻)
   纯 HTML + CSS，零依赖；图片用占位框，便于后续替换
   ========================================================================== */

/* ---------- 1. 设计 Token ---------- */
:root {
    /* VI V1.1 主色 */
    --deep:   #011F69;   /* 最深品牌蓝 */
    --brand:  #004B92;   /* 齐犇蓝 */
    --sky:    #3E8CCF;   /* 天际蓝 */
    --ink:    #1E293B;
    --muted:  #64748B;
    --cloud:  #F8FAFC;
    --pale:   #EEF4FA;
    --line:   #DBE6F1;
    --white:  #FFFFFF;
    --accent: #FF6B35;

    /* PLAN B 三层深蓝 */
    --hero-deep:     #003B75;
    --coverage-deep: #001D45;
    --footer-deep:   #001936;

    --font: "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
    --max: 1240px;
}

/* ---------- 2. Reset ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font);
    color: var(--ink);
    background: var(--white);
    line-height: 1.6;
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }

/* ---------- 3. 通用布局 ---------- */
.container {
    max-width: var(--max);
    margin: 0 auto;
    padding: 0 40px;
}
.section { padding: 100px 0; }

.section-heading { margin-bottom: 56px; }
.section-heading.centered {
    text-align: center;
    max-width: 760px;
    margin-left: auto;
    margin-right: auto;
}
.section-heading.centered .section-kicker { display: inline-flex; }

.section-kicker {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--sky);
    margin-bottom: 16px;
}
.section-kicker::before {
    content: "";
    width: 28px;
    height: 2px;
    background: var(--sky);
}
.section-heading.centered .section-kicker::before { display: none; }

.section h2 {
    font-size: 38px;
    font-weight: 700;
    line-height: 1.25;
    color: var(--ink);
    letter-spacing: -0.01em;
}
.section h2 + p {
    margin-top: 20px;
    font-size: 16px;
    color: var(--muted);
    max-width: 680px;
}
.section-heading.centered h2 + p { margin-left: auto; margin-right: auto; }

/* 深色区标题反白 */
.solutions-section h2,
.coverage-section h2,
.cta-section h2 { color: var(--white); }
.solutions-section .section-kicker,
.coverage-section .section-kicker { color: var(--sky); }
.solutions-section h2 + p,
.coverage-section p { color: rgba(255,255,255,0.78); }

/* ---------- 4. 按钮 ---------- */
.button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 15px;
    font-weight: 600;
    border-radius: 6px;
    border: 1px solid transparent;
    transition: all 0.2s ease;
    white-space: nowrap;
}
.button-primary { background: var(--brand); color: var(--white); }
.button-primary:hover { background: var(--deep); transform: translateY(-1px); }
.button-accent { background: var(--accent); color: var(--white); }
.button-accent:hover { background: #E85A28; transform: translateY(-1px); }
.button-outline {
    background: transparent;
    color: var(--white);
    border-color: rgba(255,255,255,0.5);
}
.button-outline:hover { border-color: var(--white); background: rgba(255,255,255,0.08); }
.button-light { background: var(--white); color: var(--deep); }
.button-light:hover { background: var(--cloud); }

.text-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-weight: 600;
    color: var(--brand);
    transition: gap 0.2s ease;
}
.text-link:hover { gap: 10px; }
.solutions-section .text-link,
.coverage-section .text-link { color: var(--sky); }

/* ==========================================================================
   5. 占位图系统 ★（核心：所有图片位置都用这个）
   --------------------------------------------------------------------------
   用法：<div class="ph ph-hero" data-zh="..." data-en="..."></div>
   或 ：<div class="ph ph-card-4-3">...</div>
   尺寸由 class 决定；建议替换图见 README.md
   ========================================================================== */
.ph {
    position: relative;
    background:
        repeating-linear-gradient(
            45deg,
            rgba(0,75,146,0.04),
            rgba(0,75,146,0.04) 12px,
            rgba(0,75,146,0.08) 12px,
            rgba(0,75,146,0.08) 24px
        ),
        var(--pale);
    border: 1px dashed var(--sky);
    color: var(--brand);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
    border-radius: 4px;
}
.ph-icon {
    font-size: 28px;
    opacity: 0.5;
    margin-bottom: 8px;
}
.ph-label {
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.04em;
}
.ph-hint {
    font-size: 11px;
    color: var(--muted);
    margin-top: 4px;
}

/* 深色背景下的占位（hero/方案/coverage） */
.ph.dark {
    background:
        repeating-linear-gradient(
            45deg,
            rgba(62,140,207,0.08),
            rgba(62,140,207,0.08) 12px,
            rgba(62,140,207,0.16) 12px,
            rgba(62,140,207,0.16) 24px
        ),
        rgba(0,29,69,0.5);
    border-color: rgba(62,140,207,0.6);
    color: rgba(255,255,255,0.85);
}
.ph.dark .ph-hint { color: rgba(255,255,255,0.55); }

/* 占位尺寸（宽高比） */
.ph-cover    { width: 100%; aspect-ratio: 21 / 9; }   /* 全宽背景，如 hero */
.ph-wide     { width: 100%; aspect-ratio: 3 / 1; }    /* 横向带状图 */
.ph-card-4-3 { width: 100%; aspect-ratio: 4 / 3; }    /* 卡片图 */
.ph-card-1-1 { width: 100%; aspect-ratio: 1 / 1; }    /* 方形卡片 */
.ph-half     { width: 100%; aspect-ratio: 4 / 3; }    /* 双栏图 */

/* ==========================================================================
   6. Header
   ========================================================================== */
.site-header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    height: 92px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 40px;
    background: transparent;
    transition: background 0.3s ease, box-shadow 0.3s ease, height 0.3s ease;
}
.site-header.scrolled {
    background: rgba(255,255,255,0.96);
    box-shadow: 0 1px 0 var(--line), 0 8px 24px rgba(0,31,105,0.08);
    height: 80px;
}
.brand { display: flex; align-items: center; height: 48px; }
.brand img { height: 48px; }
/* 透明态显示白色 logo，滚动后显示深色 logo */
.brand-logo-light { display: block; }
.brand-logo-default { display: none; }
.site-header.scrolled .brand-logo-light { display: none; }
.site-header.scrolled .brand-logo-default { display: block; }

.desktop-nav { display: flex; align-items: center; gap: 36px; }
.nav-item > a {
    font-size: 15px;
    font-weight: 500;
    color: rgba(255,255,255,0.92);
    transition: color 0.2s ease;
    padding: 8px 0;
}
.site-header.scrolled .nav-item > a { color: var(--ink); }
.nav-item > a:hover { color: var(--sky); }

/* ★ 下拉菜单 */
.nav-item { position: relative; }
.nav-item.has-submenu > a::after {
    content: "";
    display: inline-block;
    width: 0;
    height: 0;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 5px solid currentColor;
    margin-left: 6px;
    vertical-align: middle;
    opacity: 0.6;
    transition: transform 0.25s ease;
}
.nav-item.has-submenu:hover > a::after {
    transform: rotate(180deg);
}
.nav-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%) translateY(-8px);
    min-width: 200px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 10px;
    box-shadow: 0 12px 40px rgba(0,31,105,0.12);
    padding: 8px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
    z-index: 200;
}
.nav-item.has-submenu:hover .nav-dropdown,
.nav-item.has-submenu:focus-within .nav-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}
.nav-dropdown a {
    display: block;
    padding: 10px 14px;
    font-size: 14px;
    color: var(--ink);
    border-radius: 6px;
    transition: background 0.15s ease, color 0.15s ease;
    white-space: nowrap;
}
.nav-dropdown a:hover {
    background: var(--pale);
    color: var(--brand);
}
/* 关于我们的下拉靠右对齐，避免溢出 */
.nav-dropdown.nav-dropdown-right {
    left: auto;
    right: 0;
    transform: translateY(-8px);
}
.nav-item.has-submenu:hover .nav-dropdown.nav-dropdown-right,
.nav-item.has-submenu:focus-within .nav-dropdown.nav-dropdown-right {
    transform: translateY(0);
}

.header-actions { display: flex; align-items: center; gap: 16px; }
/* 联系我们（原关于下拉项提升为导航常驻链接） */
.header-contact {
    color: var(--white);
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    opacity: 0.92;
    transition: opacity 0.2s ease;
}
.header-contact:hover { opacity: 1; }
.site-header.scrolled .header-contact { color: var(--ink); }
.site-header.scrolled .header-contact:hover { color: var(--brand); }
.language-button {
    background: transparent;
    border: 1px solid rgba(255,255,255,0.4);
    color: var(--white);
    padding: 6px 14px;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 600;
    transition: all 0.2s ease;
}
.language-button:hover { border-color: var(--white); }
.site-header.scrolled .language-button { border-color: var(--line); color: var(--ink); }
.site-header.scrolled .language-button:hover { border-color: var(--brand); color: var(--brand); }

.header-cta { padding: 10px 22px; font-size: 14px; }
.site-header.scrolled .header-cta { background: var(--brand); color: var(--white); }

.menu-button {
    display: none;
    width: 44px; height: 44px;
    background: transparent;
    border: 0;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
}
.menu-button span {
    display: block;
    width: 24px; height: 2px;
    background: var(--white);
    transition: all 0.3s ease;
}
.site-header.scrolled .menu-button span { background: var(--ink); }
.menu-button.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-button.open span:nth-child(2) { opacity: 0; }
.menu-button.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-nav {
    position: fixed;
    top: 0; right: 0;
    width: 86%; max-width: 360px;
    height: 100vh;
    background: var(--white);
    box-shadow: -10px 0 40px rgba(0,0,0,0.15);
    transform: translateX(100%);
    transition: transform 0.3s ease;
    padding: 96px 32px 32px;
    overflow-y: auto;
    z-index: 99;
    display: flex;
    flex-direction: column;
    gap: 18px;
}
.mobile-nav.open { transform: translateX(0); }
.mobile-nav a { font-size: 16px; font-weight: 500; color: var(--ink); }
.mobile-nav a.mobile-nav-cta {
    margin-top: auto;
    padding: 14px 24px;
    background: var(--brand);
    color: var(--white);
    border-radius: 6px;
    text-align: center;
    font-weight: 600;
}
body.nav-open { overflow: hidden; }

/* ==========================================================================
   7. Hero
   ========================================================================== */
.hero {
    position: relative;
    min-height: 920px;
    display: flex;
    align-items: center;
    padding: 120px 40px 80px;
    overflow: hidden;
    color: var(--white);
}
/* Hero 背景占位：绝对定位铺满 */
.hero-ph {
    position: absolute;
    inset: 0;
    z-index: 0;
    border-radius: 0;
    border: none;
    aspect-ratio: auto;
}
.hero-inner {
    position: relative;
    z-index: 1;
    max-width: var(--max);
    margin: 0 auto;
    width: 100%;
}
.hero-copy { max-width: 640px; }
.hero-en {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.25em;
    color: var(--sky);
    text-transform: uppercase;
    margin-bottom: 20px;
}
.hero h1 {
    font-size: 60px;
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.01em;
    margin-bottom: 20px;
}
.hero-subtitle {
    font-size: 24px;
    font-weight: 500;
    color: rgba(255,255,255,0.92);
    margin-bottom: 16px;
}
.hero-lead {
    font-size: 17px;
    line-height: 1.7;
    color: rgba(255,255,255,0.8);
    margin-bottom: 36px;
    max-width: 560px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-response {
    margin-top: 24px;
    font-size: 13px;
    color: rgba(255,255,255,0.6);
}

/* ==========================================================================
   8. Intro 价值主张（全宽背景图 + 文字叠加）
   浅色背景图 → 文字用深色
   ========================================================================== */
.intro-section {
    position: relative;
    padding: 120px 40px;
    background: var(--cloud);
    color: var(--ink);
    overflow: hidden;
}
/* 背景图占位：绝对定位铺满 */
.intro-ph {
    position: absolute;
    inset: 0;
    z-index: 0;
    border-radius: 0;
    border: none;
    aspect-ratio: auto;
}
.intro-inner {
    position: relative;
    z-index: 1;
    max-width: var(--max);
    margin: 0 auto;
    width: 100%;
}
.intro-copy { max-width: 100%; }
.intro-copy .section-kicker { color: var(--brand); }
.intro-copy .section-kicker::before { background: var(--brand); }
.intro-copy h2 {
    font-size: 38px;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.01em;
    color: var(--deep);
    margin-bottom: 20px;
}
.intro-copy > p {
    font-size: 16px;
    line-height: 1.75;
    color: var(--ink);
    margin-bottom: 40px;
    max-width: 720px;
}
/* ★ 三大价值点：单行横排（图标 + 文字横排，3 列平铺）*/
.intro-points {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    padding-top: 32px;
    border-top: 1px solid var(--line);
}
.intro-points li {
    display: flex;
    flex-direction: row;
    align-items: flex-start;
    gap: 16px;
}
.intro-points .point-icon {
    width: 40px;
    height: 40px;
    background: var(--pale);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.intro-points .point-icon img {
    width: 24px;
    height: 24px;
}
.intro-points .point-text {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding-top: 4px;
}
.intro-points strong {
    font-size: 16px;
    font-weight: 700;
    color: var(--ink);
    line-height: 1.3;
}
.intro-points span {
    font-size: 13px;
    color: var(--muted);
    line-height: 1.5;
}

/* ==========================================================================
   9. Stats 数据条（全宽背景图 + 文字叠加 + 图标）
   ========================================================================== */
.stats-section {
    position: relative;
    padding: 140px 40px;  /* 高度增加：原 70px → 140px */
    background: var(--brand);
    color: var(--white);
    overflow: hidden;
}
/* 背景图占位：绝对定位铺满 */
.stats-ph {
    position: absolute;
    inset: 0;
    z-index: 0;
    border-radius: 0;
    border: none;
    aspect-ratio: auto;
}
.stats-grid {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    max-width: var(--max);
    margin: 0 auto;
    text-align: center;
}
.stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
}
.stat-icon {
    width: 72px;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.stat strong {
    display: block;
    font-size: 52px;
    font-weight: 700;
    line-height: 1.1;
    color: var(--white);
    letter-spacing: -0.02em;
}
.stat span {
    font-size: 14px;
    color: rgba(255,255,255,0.85);
    letter-spacing: 0.02em;
}
.stats-note {
    position: relative;
    z-index: 1;
    text-align: center;
    margin-top: 48px;
    font-size: 12px;
    color: rgba(255,255,255,0.7);
    max-width: 760px;
    margin-left: auto;
    margin-right: auto;
}

/* ==========================================================================
   10. Products 产品与服务
   ========================================================================== */
.products-section { background: var(--white); }
.product-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.product-card {
    padding: 36px 28px;
    background: var(--cloud);
    border: 1px solid var(--line);
    border-radius: 12px;
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
}
.product-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(1,31,105,0.1);
    border-color: var(--sky);
    background: var(--white);
}
.product-icon {
    width: 56px; height: 56px;
    border-radius: 12px;
    background: var(--pale);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}
.product-icon img {
    width: 32px;
    height: 32px;
}
.product-title { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 12px; }
.product-title h3 { font-size: 18px; font-weight: 700; color: var(--ink); }
.badge {
    display: inline-block;
    padding: 2px 8px;
    font-size: 11px;
    font-weight: 600;
    border-radius: 3px;
    background: var(--pale);
    color: var(--sky);
}
.product-card p {
    font-size: 14px;
    color: var(--muted);
    line-height: 1.7;
    margin-bottom: 20px;
    flex-grow: 1;
}
.product-card .text-link { font-size: 14px; }

/* ==========================================================================
   11. Solutions 行业方案（通栏背景图铺满 + 标题/tab/文字全在背景图上）
   --------------------------------------------------------------------------
   结构：
   ┌━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ ← section 通栏背景图
   ┃ container (1240px 居中)                        ┃
   ┃   解决方案（kicker）                            ┃
   ┃   行业场景化连接方案（h2）                       ┃
   ┃   说明文字                                      ┃
   ┃                                                ┃
   ┃   [tab1] [tab2] [tab3] [tab4]  ← 水平 tab       ┃
   ┃                                                ┃
   ┃   方案 01                                       ┃
   ┃   车联网与物流                                  ┃ ← 文字 panel
   ┃   描述...                                       ┃   （叠在背景图上）
   ┃   查看方案 →                                    ┃
   ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
   ========================================================================== */
.solutions-section {
    position: relative;
    background: var(--hero-deep);
    color: var(--white);
    overflow: hidden;
    /* 取消默认 .section padding，改用自定义（因为内容结构更复杂） */
    padding: 0;
}

/* ★ 通栏背景图层：4 张图绝对定位叠在 section 上，crossfade */
.solution-bg-layer {
    position: absolute;
    inset: 0;
    z-index: 0;
}
.solution-bg {
    position: absolute;
    inset: 0;
    background-size: cover;
    background-position: center;
    opacity: 0;
    transition: opacity 0.7s ease;
}
.solution-bg.active { opacity: 1; }

/* 左侧局部叠层：只压暗文字区，右侧背景图保持原样亮 */
.solutions-section::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    width: 50%;  /* 只覆盖左半边 */
    z-index: 1;
    background: linear-gradient(90deg, rgba(0,29,69,0.85) 0%, rgba(0,29,69,0.55) 60%, rgba(0,29,69,0) 100%);
    pointer-events: none;
}

/* container 内容层提到背景图之上 */
.solutions-section .container {
    position: relative;
    z-index: 2;
    padding-top: 100px;
    padding-bottom: 100px;
}

/* 标题区（与全局 .section h2 保持一致：38px） */
.solutions-section .section-heading { margin-bottom: 48px; }
.solutions-section .section-kicker { color: var(--sky); }
.solutions-section h2 {
    font-size: 38px;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.01em;
    color: var(--white);
    margin-bottom: 0;
}
.solutions-section h2 + p {
    margin-top: 20px;
    font-size: 16px;
    line-height: 1.7;
    color: rgba(255,255,255,0.78);
    max-width: 680px;
}

/* ★ 水平 tab（在标题下方） */
.solution-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0;
    border-bottom: 1px solid rgba(255,255,255,0.2);
    margin-bottom: 56px;
}
.solution-tab {
    background: transparent;
    border: none;
    border-bottom: 3px solid transparent;
    color: rgba(255,255,255,0.65);
    padding: 16px 24px;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.25s ease;
    cursor: pointer;
    margin-bottom: -1px;  /* 覆盖父级 border-bottom */
    display: inline-flex;
    align-items: center;
    gap: 10px;
}
.solution-tab:hover {
    color: var(--white);
}
.solution-tab.active {
    color: var(--white);
    border-bottom-color: var(--accent);
}
/* tab 内的图标：纯图标无背景 */
.solution-tab .tab-icon {
    width: 22px;
    height: 22px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    opacity: 0.7;
    transition: opacity 0.25s ease;
}
.solution-tab .tab-icon img {
    width: 22px;
    height: 22px;
    filter: brightness(0) invert(1);  /* 图标反白 */
}
.solution-tab:hover .tab-icon { opacity: 0.9; }
.solution-tab.active .tab-icon { opacity: 1; }
.solution-tab .tab-arrow {
    opacity: 0;
    transition: opacity 0.25s ease, transform 0.25s ease;
}
.solution-tab.active .tab-arrow {
    opacity: 1;
    transform: translateX(2px);
}

/* ★ 文字 panel：4 个方案文字层叠，通过 opacity 切换 */
.solution-panels {
    position: relative;
    min-height: 260px;
}
.solution-panel {
    position: absolute;
    inset: 0;
    opacity: 0;
    transition: opacity 0.5s ease;
    pointer-events: none;
    max-width: 560px;
}
.solution-panel.active {
    opacity: 1;
    pointer-events: auto;
}
.solution-panel .panel-kicker {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--sky);
    margin-bottom: 14px;
}
.solution-panel h3 {
    font-size: 28px;
    font-weight: 700;
    color: var(--white);
    line-height: 1.25;
    letter-spacing: -0.01em;
    margin-bottom: 16px;
}
.solution-panel p {
    font-size: 17px;
    line-height: 1.8;
    color: rgba(255,255,255,0.88);
    margin-bottom: 28px;
}
.solution-panel .text-link {
    color: var(--white);
    font-weight: 600;
    font-size: 15px;
    padding-bottom: 4px;
    border-bottom: 1px solid rgba(255,255,255,0.4);
}
.solution-panel .text-link:hover { border-bottom-color: var(--white); }

/* ==========================================================================
   11.5 客户与合作（标题 + Logo 墙，浅色底）
   --------------------------------------------------------------------------
   注：区块挂 .section 通用类，padding/标题字号走全局规则；
   这里只定义背景色和 Logo 墙专属样式。
   ========================================================================== */
.clients-section {
    background: var(--cloud);
}
.clients-section .section-heading { margin-bottom: 56px; }

/* Logo 墙网格：16 个客户 Logo，桌面 6 列；flex 布局让末行居中收尾 */
.clients-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    max-width: var(--max);
    margin: 0 auto;
    padding: 0 40px;
}

/* 单个 Logo 卡片 */
.client-logo {
    width: calc((100% - 100px) / 6); /* 6 列：扣除 5 个 20px 间距 */
    box-sizing: border-box;
    aspect-ratio: 16 / 9;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px;
    transition: all 0.25s ease;
    position: relative;
    overflow: hidden;
}
.client-logo:hover {
    border-color: var(--sky);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(1,31,105,0.08);
}
.client-logo img {
    max-width: 80%;
    max-height: 70%;
    object-fit: contain;
    position: relative;
    z-index: 1;
}

/* ==========================================================================
   11.6 客户案例（3 列卡片，深空蓝底，符合"深浅深浅"节奏）
   ========================================================================== */
.cases-section {
    background: var(--deep);
    color: var(--white);
}
/* 标题区在深色背景上的反白处理 */
.cases-section .section-heading h2,
.cases-section .section-heading h2 + p {
    color: var(--white);
}
.cases-section .section-heading h2 + p {
    color: rgba(255,255,255,0.78);
}
.cases-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}
.case-card {
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.18);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
    position: relative;
}
.case-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(0,0,0,0.3);
    border-color: var(--sky);
    background: rgba(255,255,255,0.10);
}
/* 顶部封面占位区（深底上用天际蓝斜纹） */
.case-cover {
    aspect-ratio: 16 / 9;
    background:
        repeating-linear-gradient(
            45deg,
            rgba(62,140,207,0.08),
            rgba(62,140,207,0.08) 12px,
            rgba(62,140,207,0.16) 12px,
            rgba(62,140,207,0.16) 24px
        ),
        rgba(0,29,69,0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--sky);
    font-size: 32px;
    position: relative;
}
.case-cover .case-cover-label {
    position: absolute;
    bottom: 12px;
    left: 12px;
    background: rgba(255,107,53,0.95);
    color: var(--white);
    font-size: 12px;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 4px;
    letter-spacing: 0.04em;
}
.case-body {
    padding: 24px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}
.case-industry {
    display: inline-block;
    align-self: flex-start;
    padding: 4px 10px;
    background: rgba(62,140,207,0.15);
    color: var(--sky);
    font-size: 11px;
    font-weight: 600;
    border-radius: 3px;
    letter-spacing: 0.04em;
    margin-bottom: 12px;
}
.case-body h3 {
    font-size: 17px;
    font-weight: 700;
    color: var(--white);
    line-height: 1.4;
    margin-bottom: 12px;
}
.case-body p {
    font-size: 14px;
    color: rgba(255,255,255,0.78);
    line-height: 1.7;
    flex-grow: 1;
    margin-bottom: 16px;
}
.case-body .text-link {
    font-size: 14px;
    color: var(--sky);
}
.case-body .text-link:hover {
    color: var(--white);
}
/* 区块底部"查看全部案例"链接也反白 */
.cases-section .section-more .text-link {
    color: var(--sky);
}
.cases-section .section-more .text-link:hover {
    color: var(--white);
}

/* ==========================================================================
   11.7 新闻动态（3 列卡片，每条 = 日期 + 标题 + 摘要）
   ========================================================================== */
.news-section {
    background: var(--cloud);
}
.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}
.news-card {
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
    position: relative;
}
.news-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(1,31,105,0.1);
    border-color: var(--sky);
}
.news-cover {
    aspect-ratio: 16 / 9;
    background:
        repeating-linear-gradient(
            45deg,
            rgba(0,75,146,0.04),
            rgba(0,75,146,0.04) 12px,
            rgba(0,75,146,0.08) 12px,
            rgba(0,75,146,0.08) 24px
        ),
        var(--pale);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--brand);
    font-size: 36px;
}
.news-body {
    padding: 24px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}
.news-date {
    font-size: 12px;
    color: var(--muted);
    margin-bottom: 12px;
    letter-spacing: 0.04em;
}
.news-body h3 {
    font-size: 17px;
    font-weight: 700;
    color: var(--ink);
    line-height: 1.4;
    margin-bottom: 12px;
    flex-grow: 1;
}
.news-body p {
    font-size: 14px;
    color: var(--muted);
    line-height: 1.7;
    margin-bottom: 16px;
}
.news-body .text-link { font-size: 14px; }

/* 区块"查看全部"链接 */
.section-more {
    text-align: center;
    margin-top: 40px;
}
.section-more .text-link {
    font-size: 15px;
}

/* ==========================================================================
   12. Coverage 全球覆盖（全宽背景图 + 文字叠加）
   ========================================================================== */
.coverage-section {
    position: relative;
    padding: 140px 40px;
    background: var(--coverage-deep);
    color: var(--white);
    overflow: hidden;
}
/* 背景图占位：绝对定位铺满 */
.coverage-ph {
    position: absolute;
    inset: 0;
    z-index: 0;
    border-radius: 0;
    border: none;
    aspect-ratio: auto;
}
.coverage-inner {
    position: relative;
    z-index: 1;
    max-width: var(--max);
    margin: 0 auto;
    width: 100%;
}
.coverage-copy { max-width: 560px; }
.coverage-copy .section-kicker { color: var(--sky); }
.coverage-copy h2 {
    font-size: 38px;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.01em;
    color: var(--white);
    margin-bottom: 20px;
}
.coverage-copy p {
    color: rgba(255,255,255,0.82);
    font-size: 16px;
    line-height: 1.8;
    margin-bottom: 28px;
}
.region-list { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 32px; }
.region-list span {
    padding: 8px 16px;
    background: rgba(255,255,255,0.12);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 20px;
    font-size: 13px;
    color: rgba(255,255,255,0.92);
    backdrop-filter: blur(4px);
}

/* ==========================================================================
   13. About 关于
   ========================================================================== */
.about-section { background: var(--white); }
.about-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}
.about-media .ph { border-radius: 12px; box-shadow: 0 20px 60px rgba(1,31,105,0.15); }
.about-copy .section-kicker { color: var(--sky); }
.about-copy h2 {
    font-size: 38px;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.01em;
    color: var(--ink);
    margin-bottom: 24px;
}
.about-copy > p {
    font-size: 16px;
    line-height: 1.8;
    color: var(--muted);
    margin-bottom: 32px;
}

/* ==========================================================================
   14. CTA
   ========================================================================== */
.cta-section {
    background: var(--brand);
    color: var(--white);
    padding: 100px 40px;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.cta-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 20% 50%, rgba(62,140,207,0.4), transparent 50%),
                radial-gradient(circle at 80% 50%, rgba(1,31,105,0.4), transparent 50%);
    z-index: 0;
}
.cta-inner { position: relative; z-index: 1; max-width: 720px; margin: 0 auto; }
.cta-inner h2 {
    font-size: 38px;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.01em;
    color: var(--white);
    margin-bottom: 20px;
}
.cta-inner p {
    font-size: 16px;
    color: rgba(255,255,255,0.82);
    margin-bottom: 36px;
    line-height: 1.7;
}
.cta-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.cta-tagline {
    margin-top: 40px;
    font-size: 13px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: rgba(255,255,255,0.6);
}

/* ==========================================================================
   15. Footer
   ========================================================================== */
.site-footer { background: var(--footer-deep); color: rgba(255,255,255,0.7); padding: 64px 0 32px; }
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    max-width: var(--max);
    margin: 0 auto;
    padding: 0 40px 48px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}
/* 页脚双 Logo 横排：联合标识 + 分割线 + TIBIOT（沿用标识），等高、总宽留有余量 */
.footer-logos { display: flex; align-items: center; gap: 16px; margin-bottom: 18px; }
.footer-logos .logo-joint { height: 64px; }
.footer-logos .logo-tibiot { height: 64px; }
.footer-logo-sep { width: 1px; height: 56px; background: rgba(255,255,255,0.22); flex: none; }
.footer-brand p { font-size: 14px; color: rgba(255,255,255,0.5); line-height: 1.7; text-align: center; }
.footer-col strong { display: block; font-size: 14px; color: var(--white); margin-bottom: 16px; font-weight: 600; }
.footer-col a,
.footer-col p { display: block; font-size: 14px; color: rgba(255,255,255,0.7); margin-bottom: 10px; line-height: 1.6; transition: color 0.2s ease; }
/* 办公地点紧凑样式（3 地地址不撑高 footer）*/
.footer-office {
    font-size: 12px !important;
    line-height: 1.5 !important;
    margin-bottom: 8px !important;
    color: rgba(255,255,255,0.55);
}
.footer-office span {
    color: rgba(255,255,255,0.85);
    font-weight: 600;
    font-size: 13px;
}
.footer-col a:hover { color: var(--sky); }
.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 40px 0;
    max-width: var(--max);
    margin: 0 auto;
    font-size: 13px;
    color: rgba(255,255,255,0.5);
    flex-wrap: wrap;
    gap: 12px;
}
.footer-legal-links { display: flex; gap: 20px; }
.footer-legal-links a:hover { color: var(--sky); }

/* ==========================================================================
   16. 悬浮联系 + 弹窗
   ========================================================================== */
.floating-contact {
    position: fixed;
    right: 24px; bottom: 24px;
    z-index: 90;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: var(--accent);
    color: var(--white);
    border: none;
    border-radius: 32px;
    font-size: 14px;
    font-weight: 600;
    box-shadow: 0 8px 24px rgba(255,107,53,0.4);
    transition: all 0.25s ease;
}
.floating-contact:hover { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(255,107,53,0.5); }

.contact-dialog {
    border: none;
    border-radius: 16px;
    padding: 0;
    max-width: 440px;
    width: calc(100% - 32px);
    background: var(--white);
    box-shadow: 0 24px 80px rgba(0,0,0,0.3);
    /* 显式居中（全局 * { margin:0 } reset 清掉了 dialog 默认的 UA margin:auto，
       导致 showModal() 后弹窗贴在视口左上角而非居中；这里补回来） */
    margin: auto;
}
.contact-dialog::backdrop { background: rgba(1,31,105,0.6); backdrop-filter: blur(4px); }
.dialog-inner { padding: 40px; position: relative; }
.dialog-close {
    position: absolute;
    top: 16px; right: 16px;
    width: 36px; height: 36px;
    border-radius: 50%;
    background: var(--cloud);
    border: none;
    font-size: 20px;
    color: var(--muted);
    transition: all 0.2s ease;
}
.dialog-close:hover { background: var(--line); color: var(--ink); }
.contact-dialog h2 { font-size: 24px; color: var(--ink); margin-bottom: 8px; margin-top: 16px; }
.contact-dialog .section-kicker { margin-bottom: 8px; }
.contact-dialog p,
.contact-dialog a { display: block; color: var(--muted); font-size: 15px; line-height: 1.7; }
.contact-dialog a.email-link { color: var(--brand); font-weight: 600; margin: 16px 0; font-size: 18px; }
.qr-placeholder {
    width: 160px; height: 160px;
    background: var(--cloud);
    border: 1px dashed var(--line);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    font-size: 13px;
    color: var(--muted);
    line-height: 1.6;
    margin: 24px 0;
}
.dialog-en { display: none; }
.contact-dialog[data-language="en"] .dialog-zh { display: none; }
.contact-dialog[data-language="en"] .dialog-en { display: block; }

/* ==========================================================================
   17. 响应式
   ========================================================================== */
@media (max-width: 1050px) {
    .desktop-nav { display: none; }
    .header-cta { display: none; }
    .menu-button { display: flex; }

    .hero h1 { font-size: 44px; }
    .hero-subtitle { font-size: 20px; }
    .hero-lead { font-size: 16px; }

    .intro-section,
    .coverage-section { padding: 72px 40px; }

    /* Intro 三大价值点：平板保持 3 列（已经是横排紧凑布局）*/
    .intro-points { gap: 24px; }

    .about-layout {
        grid-template-columns: 1fr;
        gap: 48px;
    }

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

    /* Solutions：平板端 tab 横向可滚动，字号略缩 */
    .solution-tabs {
        overflow-x: auto;
        flex-wrap: nowrap;
        -webkit-overflow-scrolling: touch;
    }
    .solution-tab { padding: 14px 20px; font-size: 14px; white-space: nowrap; }
    .solution-panels { min-height: 240px; }
    .solution-panel h3 { font-size: 24px; }

    /* 客户 Logo 墙：平板 4 列 */
    .clients-grid .client-logo { width: calc((100% - 60px) / 4); } /* 平板 4 列 */

    /* 客户案例 / 新闻动态：平板 2 列 */
    .cases-grid,
    .news-grid { grid-template-columns: repeat(2, 1fr); }

    .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}

@media (max-width: 720px) {
    .container,
    .intro-layout,
    .stats-grid,
    .product-grid,
    .coverage-layout,
    .about-layout,
    .footer-grid { padding-left: 20px; padding-right: 20px; }
    /* 小屏页脚双 Logo 缩小，保证横排放得下 */
    .footer-logos { gap: 10px; }
    .footer-logos .logo-joint, .footer-logos .logo-tibiot { height: 48px; }
    .footer-logo-sep { height: 40px; }

    .section { padding: 64px 0; }
    .section h2 { font-size: 26px; }
    .section-heading { margin-bottom: 40px; }

    .site-header { padding: 0 20px; height: 72px; }
    .site-header.scrolled { height: 68px; }
    /* 小屏 Logo 缩小，避免挤占菜单按钮空间 */
    .brand { height: 36px; }
    .brand img { height: 36px; }

    .hero { min-height: 600px; padding: 100px 20px 60px; }
    .hero h1 { font-size: 32px; }
    .hero-subtitle { font-size: 18px; }
    .hero-lead { font-size: 15px; }
    .hero-actions { flex-direction: column; }
    .hero-actions .button { width: 100%; justify-content: center; }

    .intro-section,
    .about-section { padding: 56px 20px; }
    .intro-copy h2,
    .about-copy h2 { font-size: 26px; line-height: 1.3; margin-bottom: 16px; }
    .intro-copy > p { font-size: 15px; line-height: 1.7; margin-bottom: 24px; }
    .intro-copy { max-width: 100%; }
    /* Solutions / Coverage 手机端 h2 同步缩小到 26px（保持一致性） */
    .solutions-section h2,
    .coverage-copy h2 { font-size: 26px; line-height: 1.3; }
    .solutions-section h2 + p,
    .coverage-copy p { font-size: 14px; }
    /* Intro 三大价值点：手机端单列堆叠 */
    .intro-points { grid-template-columns: 1fr; gap: 16px; padding-top: 24px; }
    .intro-points li { gap: 12px; }
    .intro-points strong { font-size: 15px; }
    .intro-points span { font-size: 12px; }
    .intro-points .point-icon { width: 36px; height: 36px; }
    .intro-points .point-icon img { width: 22px; height: 22px; }

    .stats-section { padding: 80px 20px; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 40px 16px; }
    .stat strong { font-size: 26px; }
    .stat-icon { width: 56px; height: 56px; }
    .stat-icon iconify-icon { width: 44px; height: 44px; }

    /* Solutions 手机端：左侧局部叠层改成全屏淡叠层（因为上下布局） */
    .solutions-section::after {
        width: 100%;
        background: linear-gradient(180deg, rgba(0,29,69,0.85) 0%, rgba(0,29,69,0.6) 50%, rgba(0,29,69,0.4) 100%);
    }

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

    /* Solutions：手机端 tab 字号更小、panel 字号缩 */
    .solution-tab { padding: 12px 14px; font-size: 13px; }
    .solution-panels { min-height: 200px; }
    .solution-panel h3 { font-size: 18px; }
    .solution-panel p { font-size: 14px; }
    .solutions-section .container { padding-top: 64px; padding-bottom: 64px; }

    /* 客户 Logo 墙：手机 3 列 */
    .clients-grid {
        gap: 12px;
        padding: 0 20px;
    }
    .clients-grid .client-logo { width: calc((100% - 24px) / 3); }

    /* 客户案例 / 新闻动态：手机 1 列 */
    .cases-grid,
    .news-grid { grid-template-columns: 1fr; gap: 20px; }

    .cta-section { padding: 64px 20px; }
    .cta-inner h2 { font-size: 26px; }
    .cta-actions { flex-direction: column; }
    .cta-actions .button { width: 100%; justify-content: center; }

    .footer-grid { grid-template-columns: 1fr; gap: 32px; padding-bottom: 32px; }
    .footer-bottom { flex-direction: column; align-items: flex-start; padding: 20px 20px 0; }

    .floating-contact { right: 16px; bottom: 16px; padding: 10px 16px; font-size: 13px; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ========== 修复版：Hero 动态背景相关样式 ========== */
/* 强制 Hero 为定位上下文并裁剪溢出，粒子绝对不会跑出容器 */
.hero {
  position: relative !important;
  overflow: hidden !important;
}

/* 背景图呼吸缩放动画 */
.hero-ph {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  animation: slowZoom 30s ease-in-out infinite alternate;
  transform-origin: center center;
}

/* 暗色蒙层 */
.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 10, 40, 0.25);
  z-index: 2;
  pointer-events: none;
}

/* 粒子画布层 - 严格限制在 Hero 内 */
#tsparticles {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 3;
  pointer-events: auto;
}

/* 背景视频层 - 位于背景图之上（同层靠 DOM 顺序覆盖）、暗色蒙层之下 */
.hero-video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  z-index: 1;
  pointer-events: none;
  background: #00061a; /* 视频加载前的底色，避免白闪 */
}

/* 视频正常播放时完全遮住背景图，停掉呼吸缩放动画省性能 */
.hero:has(.hero-video) .hero-ph {
  animation: none;
}

/* 内容层 - 强制置顶，绝对不会被粒子挡住 */
.hero-inner {
  position: relative !important;
  z-index: 10 !important;
  pointer-events: none;
}

/* 可点击元素恢复鼠标事件 */
.hero-inner a,
.hero-inner button {
  pointer-events: auto;
}

/* 缓慢缩放关键帧 */
@keyframes slowZoom {
  0% { transform: scale(1); }
  100% { transform: scale(1.36); }
}

/* 无障碍适配 */
@media (prefers-reduced-motion: reduce) {
  .hero-ph { animation: none; }
  #tsparticles { display: none; }
  .hero-video { display: none; } /* 回退静态图 */
}

/* 移动端关闭悬停交互 */
@media (max-width: 768px) {
  #tsparticles {
    pointer-events: none;
  }
  /* 小屏回退静态图：动效不可见但流量可观 */
  .hero-video { display: none; }
}

/* ==========================================================================
   Iconify 图标兼容层（tabler 图标集，替代自制 SVG）
   让 <iconify-icon> 继承各场景的 img 尺寸/颜色规则
   ========================================================================== */

/* 全局：iconify-icon 不超过容器 */
iconify-icon {
    display: inline-flex;
    flex-shrink: 0;
    vertical-align: middle;
}

/* intro-points 图标 */
.intro-points .point-icon iconify-icon {
    width: 22px;
    height: 22px;
    color: var(--brand);
}

/* stat-icon（Stats 数据条，大图标配大数字） */
.stat-icon iconify-icon {
    width: 56px;
    height: 56px;
    color: var(--white);
    opacity: 0.95;
}

/* product-icon（产品卡） */
.product-icon iconify-icon {
    width: 32px;
    height: 32px;
    color: var(--brand);
}

/* solution-tab（行业方案 tab 图标） */
.solution-tab .tab-icon iconify-icon {
    width: 22px;
    height: 22px;
    color: inherit;
    filter: brightness(0) invert(1);  /* 反白（和原 SVG 处理一致）*/
}
.solution-tab.active .tab-icon iconify-icon {
    opacity: 1;
}
/* 2026-10-16 手机端导航修正：抽屉二级链接组 + 顶部联系我们隐藏（与菜单重复且挤压折行） */
.mobile-nav .mobile-sub { display: flex; flex-direction: column; margin: 0 0 10px 26px; padding-left: 14px; border-left: 2px solid rgba(0,75,146,0.18); }
.mobile-nav .mobile-sub a { font-size: 13px; font-weight: 400; color: var(--muted); padding: 5px 0; }
@media (max-width: 720px) {
    .header-contact { display: none; }
}

/* 2026-10-19：Hero 视频仅在 ≥1600 全宽 PC 展示；笔记本/中屏回退静态图+粒子动效（15.6MB 视频中屏加载慢） */
.hero-video { display: none; }
@media (min-width: 1920px) and (prefers-reduced-motion: no-preference) {
    .hero-video { display: block; }
}