/* ============================================
   飞扬膜结构 - 官方网站样式表
   设计风格：简约大气 · 科技蓝点缀 · Apple风格
   ============================================ */

/* ---------- CSS 变量 ---------- */
:root {
    --c-primary: #0A6CFF;
    --c-primary-dark: #0050D8;
    --c-primary-light: #E8F1FF;
    --c-dark: #1A1A1A;
    --c-text: #2D2D2D;
    --c-text-sub: #6B7280;
    --c-text-light: #9CA3AF;
    --c-border: #E5E7EB;
    --c-bg: #FFFFFF;
    --c-bg-soft: #F9FAFB;
    --c-bg-gray: #F3F4F6;
    --c-accent: #00C2A8;
    --shadow-sm: 0 1px 3px rgba(0,0,0,.06);
    --shadow-md: 0 4px 20px rgba(0,0,0,.08);
    --shadow-lg: 0 12px 40px rgba(0,0,0,.12);
    --radius: 14px;
    --radius-sm: 8px;
    --max-w: 1280px;
    --header-h: 100px;
    --topbar-h: 36px;
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

/* ---------- 重置 ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
    font-family: var(--font);
    color: var(--c-text);
    background: var(--c-bg);
    line-height: 1.7;
    font-size: 16px;
    overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: color .25s ease; }
ul, ol { list-style: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

/* ---------- 通用容器 ---------- */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }
.section { padding: 96px 0; }
.section-soft { background: var(--c-bg-soft); }

/* ---------- 区块标题 ---------- */
.section-head { text-align: center; margin-bottom: 56px; }
.section-head .eyebrow {
    display: inline-block;
    font-size: 13px;
    letter-spacing: 2px;
    color: var(--c-primary);
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: 14px;
}
.section-head h2 {
    font-size: clamp(26px, 4vw, 40px);
    font-weight: 700;
    color: var(--c-dark);
    line-height: 1.3;
    letter-spacing: -.5px;
}
.section-head .desc {
    margin-top: 18px;
    font-size: 16px;
    color: var(--c-text-sub);
    max-width: 680px;
    margin-left: auto;
    margin-right: auto;
}

/* ============================================
   头部 + Hero（导航与Banner一体化）
   ============================================ */
#header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    height: var(--header-h);
    display: flex;
    flex-direction: column;
    background: rgba(255,255,255,.92);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid transparent;
    transition: background .3s ease, border-color .3s ease, box-shadow .3s ease, transform .3s ease;
}
#header.scrolled {
    background: rgba(255,255,255,.96);
    border-bottom-color: var(--c-border);
    box-shadow: var(--shadow-sm);
}
/* 顶部信息条 */
.top-bar {
    height: var(--topbar-h);
    background: #0A1E3C;
    color: #fff;
    flex-shrink: 0;
    transition: opacity .3s ease;
}
.top-bar-inner {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 13px;
}
.top-bar .top-company { font-weight: 600; letter-spacing: .5px; }
.top-bar .top-contact { display: flex; align-items: center; gap: 6px; color: rgba(255,255,255,.9); }
.top-bar .top-contact svg { color: var(--c-accent); }
.top-bar .top-contact a { color: #fff; font-weight: 700; transition: color .2s ease; }
.top-bar .top-contact a:hover { color: var(--c-accent); }
.header-inner {
    flex: 1;
    width: 100%;
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Logo */
.logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.logo-text {
    font-size: 22px;
    font-weight: 800;
    color: var(--c-primary);
    letter-spacing: -.5px;
    display: flex;
    align-items: flex-start;
    line-height: 1;
}
.logo-text .reg {
    font-size: 11px;
    font-weight: 700;
    color: var(--c-primary);
    margin: -2px 0 0 1px;
    vertical-align: super;
}
.logo-sep {
    color: var(--c-text-sub);
    font-weight: 300;
    font-size: 20px;
}
.logo-sub {
    font-size: 14px;
    font-weight: 600;
    color: var(--c-dark);
    letter-spacing: 1px;
}

/* 导航 */
.nav { display: flex; align-items: center; gap: 4px; }
.nav a {
    padding: 8px 16px;
    font-size: 15px;
    font-weight: 500;
    color: var(--c-text);
    border-radius: var(--radius-sm);
    transition: all .2s ease;
}
.nav a:hover { color: var(--c-primary); background: var(--c-primary-light); }
.nav .nav-cta {
    background: var(--c-primary);
    color: #fff;
    padding: 9px 22px;
    margin-left: 10px;
}
.nav .nav-cta:hover { background: var(--c-primary-dark); color: #fff; }

/* 移动端菜单按钮 */
.menu-toggle {
    display: none;
    width: 40px; height: 40px;
    border-radius: var(--radius-sm);
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 5px;
}
.menu-toggle span {
    display: block;
    width: 22px; height: 2px;
    background: var(--c-dark);
    border-radius: 2px;
    transition: all .3s ease;
}
.menu-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============================================
   Hero Banner
   ============================================ */
#hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: url('../img/mjgtcp/mjgtcp40.png') center center / cover no-repeat, #062B6D;
    overflow: hidden;
    padding-top: var(--header-h);
}
#hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(120deg, rgba(6,43,109,.92) 0%, rgba(10,108,255,.78) 60%, rgba(6,43,109,.85) 100%);
    pointer-events: none;
}
#hero::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 120px;
    background: linear-gradient(to top, var(--c-bg), transparent);
    pointer-events: none;
}
.hero-grid-bg {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
    mask-image: radial-gradient(ellipse at center, #000 30%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, #000 30%, transparent 70%);
}
.hero-content {
    position: relative;
    z-index: 2;
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 24px;
    width: 100%;
}
.hero-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 18px;
    background: rgba(255,255,255,.12);
    border: 1px solid rgba(255,255,255,.2);
    border-radius: 100px;
    color: #fff;
    font-size: 13px;
    font-weight: 500;
    margin-bottom: 28px;
    backdrop-filter: blur(10px);
}
.hero-tag .dot {
    width: 8px; height: 8px;
    background: var(--c-accent);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: .5; transform: scale(1.3); }
}
.hero-content h1 {
    font-size: clamp(34px, 6vw, 60px);
    font-weight: 800;
    color: #fff;
    line-height: 1.15;
    letter-spacing: -1px;
    margin-bottom: 22px;
    max-width: 900px;
}
.hero-content h1 .accent { color: #5BACFF; }
.hero-content .hero-sub {
    font-size: clamp(16px, 2vw, 19px);
    color: rgba(255,255,255,.78);
    max-width: 640px;
    margin-bottom: 40px;
    line-height: 1.6;
}
.hero-btns { display: flex; gap: 16px; flex-wrap: wrap; }
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 15px 32px;
    font-size: 15px;
    font-weight: 600;
    border-radius: 100px;
    transition: all .25s ease;
    white-space: nowrap;
}
.btn-primary { background: #fff; color: var(--c-primary); }
.btn-primary:hover { background: var(--c-primary); color: #fff; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.2); }
.btn-ghost { background: rgba(255,255,255,.1); color: #fff; border: 1px solid rgba(255,255,255,.3); }
.btn-ghost:hover { background: rgba(255,255,255,.2); border-color: rgba(255,255,255,.5); }

.hero-stats {
    display: flex;
    gap: 48px;
    margin-top: 64px;
    flex-wrap: wrap;
}
.hero-stat .num {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 800;
    color: #fff;
    line-height: 1;
}
.hero-stat .num span { font-size: .6em; font-weight: 600; color: #5BACFF; }
.hero-stat .label {
    font-size: 14px;
    color: rgba(255,255,255,.6);
    margin-top: 8px;
}

/* ============================================
   公司介绍
   ============================================ */
#about { background: var(--c-bg); }
.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 64px;
    align-items: center;
}
.about-text p { color: var(--c-text-sub); font-size: 16px; margin-bottom: 18px; line-height: 1.85; }
.about-text p strong { color: var(--c-dark); font-weight: 600; }
.about-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 28px;
}
.about-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 18px;
    background: var(--c-primary-light);
    color: var(--c-primary);
    border-radius: 100px;
    font-size: 14px;
    font-weight: 600;
}
.about-tag svg { width: 1em; height: 1em; fill: currentColor; }

.about-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}
.about-feature {
    padding: 28px 24px;
    background: var(--c-bg-soft);
    border-radius: var(--radius);
    border: 1px solid var(--c-border);
    transition: all .3s ease;
}
.about-feature:hover { border-color: var(--c-primary); background: #fff; box-shadow: var(--shadow-md); transform: translateY(-4px); }
.about-feature .af-num {
    font-size: 32px;
    font-weight: 800;
    color: var(--c-primary);
    line-height: 1;
}
.about-feature .af-num span { font-size: 16px; color: var(--c-text-sub); font-weight: 600; }
.about-feature .af-label { font-size: 14px; color: var(--c-text-sub); margin-top: 10px; font-weight: 500; }

/* ============================================
   产品展示
   ============================================ */
#products { background: var(--c-bg-soft); }
.product-tabs {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 48px;
}
.product-tab {
    padding: 10px 24px;
    font-size: 14px;
    font-weight: 600;
    color: var(--c-text-sub);
    background: #fff;
    border: 1px solid var(--c-border);
    border-radius: 100px;
    transition: all .25s ease;
}
.product-tab:hover { color: var(--c-primary); border-color: var(--c-primary); }
.product-tab.active {
    background: var(--c-primary);
    color: #fff;
    border-color: var(--c-primary);
    box-shadow: 0 4px 14px rgba(10,108,255,.3);
}
.product-panel { display: none; }
.product-panel.active { display: block; animation: fadeIn .4s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }

.product-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}
.product-card {
    background: #fff;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--c-border);
    transition: all .3s ease;
    cursor: pointer;
}
.product-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--c-primary); }
.product-card .pc-img {
    aspect-ratio: 4 / 3;
    overflow: hidden;
    background: var(--c-bg-gray);
    position: relative;
}
.product-card .pc-img img {
    width: 100%; height: 100%;
    object-fit: cover;
    transition: transform .5s ease;
}
.product-card:hover .pc-img img { transform: scale(1.06); }
.product-card .pc-img::after {
    content: '点击放大';
    position: absolute;
    inset: 0;
    background: rgba(10,108,255,.7);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 600;
    opacity: 0;
    transition: opacity .25s ease;
}
.product-card:hover .pc-img::after { opacity: 1; }
.product-card .pc-info { padding: 14px 16px; }
.product-card .pc-name {
    font-size: 15px;
    font-weight: 600;
    color: var(--c-dark);
    margin-bottom: 4px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.product-card .pc-desc {
    font-size: 13px;
    color: var(--c-text-sub);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 1;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ============================================
   应用领域
   ============================================ */
#applications { background: var(--c-bg); }
.app-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
}
.app-card {
    padding: 32px 20px;
    text-align: center;
    background: var(--c-bg-soft);
    border-radius: var(--radius);
    border: 1px solid var(--c-border);
    transition: all .3s ease;
}
.app-card:hover { background: #fff; border-color: var(--c-primary); box-shadow: var(--shadow-md); transform: translateY(-4px); }
.app-card .app-icon {
    width: 52px; height: 52px;
    margin: 0 auto 16px;
    background: var(--c-primary-light);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--c-primary);
    transition: all .3s ease;
}
.app-card:hover .app-icon { background: var(--c-primary); color: #fff; transform: rotate(-5deg) scale(1.05); }
.app-card .app-icon svg { width: 26px; height: 26px; }
.app-card h3 { font-size: 16px; font-weight: 700; color: var(--c-dark); margin-bottom: 6px; }
.app-card p { font-size: 13px; color: var(--c-text-sub); line-height: 1.5; }

/* ============================================
   工程案例
   ============================================ */
#cases { background: var(--c-bg-soft); }
.case-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
}
.case-card {
    background: #fff;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--c-border);
    transition: all .3s ease;
}
.case-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.case-card .cc-img {
    aspect-ratio: 16 / 10;
    overflow: hidden;
    background: var(--c-bg-gray);
    position: relative;
}
.case-card .cc-img img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
.case-card:hover .cc-img img { transform: scale(1.05); }
.case-card .cc-region {
    position: absolute;
    top: 12px; left: 12px;
    background: rgba(10,108,255,.92);
    color: #fff;
    font-size: 12px;
    font-weight: 600;
    padding: 5px 12px;
    border-radius: 100px;
    backdrop-filter: blur(4px);
}
.case-card .cc-info { padding: 16px 18px; }
.case-card .cc-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--c-dark);
    margin-bottom: 4px;
}
.case-card .cc-desc { font-size: 13px; color: var(--c-text-sub); }

/* ============================================
   FAQ 问答
   ============================================ */
#faq { background: var(--c-bg); }
.faq-list { max-width: 820px; margin: 0 auto; }
.faq-item {
    border: 1px solid var(--c-border);
    border-radius: var(--radius);
    margin-bottom: 14px;
    overflow: hidden;
    background: #fff;
    transition: border-color .25s ease, box-shadow .25s ease;
}
.faq-item:hover { border-color: var(--c-primary); }
.faq-item.open { border-color: var(--c-primary); box-shadow: var(--shadow-md); }
.faq-question {
    width: 100%;
    text-align: left;
    padding: 20px 24px;
    font-size: 16px;
    font-weight: 600;
    color: var(--c-dark);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    transition: color .2s ease;
}
.faq-question:hover { color: var(--c-primary); }
.faq-question .q-icon {
    flex-shrink: 0;
    width: 24px; height: 24px;
    border-radius: 50%;
    background: var(--c-primary-light);
    color: var(--c-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
    transition: all .3s ease;
}
.faq-item.open .q-icon { background: var(--c-primary); color: #fff; transform: rotate(45deg); }
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height .35s ease;
}
.faq-answer-inner {
    padding: 0 24px 22px;
    font-size: 15px;
    color: var(--c-text-sub);
    line-height: 1.8;
}

/* ============================================
   联系方式
   ============================================ */
#contact { background: linear-gradient(135deg, #0A6CFF 0%, #062B6D 100%); color: #fff; overflow: hidden; }
#contact::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 15% 20%, rgba(255,255,255,.08) 0%, transparent 35%),
        radial-gradient(circle at 85% 80%, rgba(0,194,168,.1) 0%, transparent 35%);
    pointer-events: none;
}
#contact .section-head h2 { color: #fff; }
#contact .section-head .eyebrow { color: #5BACFF; }
#contact .section-head .desc { color: rgba(255,255,255,.7); }
.contact-grid {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 48px;
    align-items: start;
    position: relative;
    z-index: 1;
}
.contact-info { display: flex; flex-direction: column; gap: 24px; }
.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 22px 26px;
    background: rgba(255,255,255,.08);
    border: 1px solid rgba(255,255,255,.15);
    border-radius: var(--radius);
    backdrop-filter: blur(10px);
    transition: all .3s ease;
}
.contact-item:hover { background: rgba(255,255,255,.12); border-color: rgba(255,255,255,.3); }
.contact-item .ci-icon {
    flex-shrink: 0;
    width: 44px; height: 44px;
    background: rgba(255,255,255,.15);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
}
.contact-item .ci-icon svg { width: 22px; height: 22px; fill: currentColor; }
.contact-item .ci-label { font-size: 13px; color: rgba(255,255,255,.6); margin-bottom: 4px; }
.contact-item .ci-value { font-size: 17px; font-weight: 600; color: #fff; }
.contact-item .ci-value a { color: #fff; }
.contact-item .ci-value a:hover { color: #5BACFF; }

.contact-qr {
    text-align: center;
    padding: 32px 28px;
    background: #fff;
    border-radius: var(--radius);
    color: var(--c-dark);
    box-shadow: var(--shadow-lg);
    min-width: 220px;
}
.contact-qr img { width: 180px; height: 180px; margin: 0 auto 16px; border-radius: 12px; }
.contact-qr .qr-title { font-size: 16px; font-weight: 700; color: var(--c-dark); margin-bottom: 4px; }
.contact-qr .qr-sub { font-size: 13px; color: var(--c-text-sub); }

/* ============================================
   城市分站导航
   ============================================ */
#city-stations { background: var(--c-bg-soft); }
.city-stations-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; }
.city-station-link { display: inline-flex; align-items: center; gap: 4px; padding: 6px 10px; background: #fff; border: 1px solid var(--c-border); border-radius: var(--radius-sm); font-size: 12px; color: var(--c-text-sub); transition: all .2s ease; }
.city-station-link:hover { color: var(--c-primary); border-color: var(--c-primary); background: var(--c-primary-light); transform: translateY(-2px); }
.city-station-link svg { width: 12px; height: 12px; fill: currentColor; opacity: .5; }
@media (max-width: 768px) {
    .city-stations-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 480px) {
    .city-stations-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ============================================
   底部
   ============================================ */
#footer {
    background: #0A0E1A;
    color: rgba(255,255,255,.6);
    padding: 40px 0 32px;
}
.footer-inner { text-align: center; }
.footer-inner p { font-size: 13px; line-height: 1.9; margin-bottom: 4px; }
.footer-inner a { color: rgba(255,255,255,.75); transition: color .2s ease; }
.footer-inner a:hover { color: #5BACFF; }
.footer-links { margin-bottom: 16px; display: flex; justify-content: center; gap: 20px; flex-wrap: wrap; font-size: 13px; }
.footer-links a:hover { color: #5BACFF; }

/* ============================================
   图片灯箱（Lightbox）
   ============================================ */
#lightbox {
    position: fixed;
    inset: 0;
    z-index: 2000;
    background: rgba(0,0,0,.9);
    display: none;
    align-items: center;
    justify-content: center;
    padding: 40px;
    opacity: 0;
    transition: opacity .3s ease;
}
#lightbox.show { display: flex; opacity: 1; }
#lightbox img {
    max-width: 90%;
    max-height: 90vh;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,.5);
}
#lightbox .lb-close {
    position: absolute;
    top: 24px; right: 24px;
    width: 44px; height: 44px;
    background: rgba(255,255,255,.15);
    border-radius: 50%;
    color: #fff;
    font-size: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background .2s ease;
}
#lightbox .lb-close:hover { background: rgba(255,255,255,.3); }
#lightbox .lb-caption {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    color: #fff;
    font-size: 15px;
    background: rgba(0,0,0,.5);
    padding: 8px 20px;
    border-radius: 100px;
    backdrop-filter: blur(4px);
}

/* ============================================
   回到顶部
   ============================================ */
#back-top {
    position: fixed;
    bottom: 32px; right: 32px;
    width: 48px; height: 48px;
    background: var(--c-primary);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all .3s ease;
    z-index: 900;
}
#back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
#back-top:hover { background: var(--c-primary-dark); transform: translateY(-3px); }
#back-top svg { width: 22px; height: 22px; fill: currentColor; }

/* ============================================
   滚动渐入动画
   ============================================ */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity .7s ease, transform .7s ease;
}
.reveal.in { opacity: 1; transform: translateY(0); }

/* ============================================
   响应式
   ============================================ */
@media (max-width: 1024px) {
    .about-grid { grid-template-columns: 1fr; gap: 40px; }
    .product-grid { grid-template-columns: repeat(3, 1fr); }
    .app-grid { grid-template-columns: repeat(3, 1fr); }
    .case-grid { grid-template-columns: repeat(2, 1fr); }
    .contact-grid { grid-template-columns: 1fr; }
    .contact-qr { max-width: 280px; margin: 0 auto; }
}

@media (max-width: 768px) {
    :root { --header-h: 92px; --topbar-h: 32px; }
    .section { padding: 64px 0; }
    .container, .header-inner, .hero-content { padding: 0 20px; }
    .section-head { margin-bottom: 40px; }

    .top-bar-inner { font-size: 12px; padding: 0 20px; }
    .top-bar .top-company { display: none; }

    .logo-text { font-size: 18px; }
    .logo-sub { font-size: 12px; }
    .logo-sep { font-size: 16px; }

    .nav {
        position: fixed;
        top: var(--header-h);
        left: 0; right: 0;
        background: #fff;
        flex-direction: column;
        padding: 16px;
        gap: 4px;
        border-bottom: 1px solid var(--c-border);
        box-shadow: var(--shadow-md);
        transform: translateY(-120%);
        transition: transform .3s ease;
        max-height: calc(100vh - var(--header-h));
        overflow-y: auto;
    }
    .nav.open { transform: translateY(0); }
    .nav a { width: 100%; padding: 14px 16px; }
    .nav .nav-cta { margin: 8px 0 0; text-align: center; }
    .menu-toggle { display: flex; }

    .hero-stats { gap: 28px; margin-top: 40px; }
    .hero-btns .btn { flex: 1; justify-content: center; padding: 14px 24px; }

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

    .faq-question { font-size: 15px; padding: 18px 18px; }
    .faq-answer-inner { padding: 0 18px 18px; font-size: 14px; }

    .contact-item { padding: 18px 20px; }
    .contact-item .ci-value { font-size: 15px; }
}

@media (max-width: 420px) {
    .product-grid { grid-template-columns: 1fr; }
    .app-grid { grid-template-columns: 1fr; }
    .hero-stats { gap: 20px; }
    .hero-stat .num { font-size: 26px; }
    .btn { padding: 13px 22px; font-size: 14px; }
    #back-top { bottom: 20px; right: 20px; width: 44px; height: 44px; }
}