/* ============================================================
   票查查官网设计系统 · 2026-09
   原则：科技、简洁；静态服务端渲染（AI 爬虫不执行 JS）
   ============================================================ */

:root {
  --c-primary: #2064e6;
  --c-primary-dark: #1a4fc4;
  --c-primary-soft: #eaf1fe;
  --c-cyan: #06b6d4;
  --c-ink: #0f172a;
  --c-body: #3b4a5f;
  --c-muted: #6b7a90;
  --c-line: #e5eaf1;
  --c-bg-alt: #f7f9fc;
  --c-dark: #0a1322;
  --c-dark-2: #0e1e3e;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .05);
  --shadow-md: 0 10px 30px rgba(15, 23, 42, .08);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, .14);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", Consolas, "Courier New", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-body);
  background: #fff;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

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

.container { max-width: 1160px; margin: 0 auto; padding: 0 24px; }

/* 跳转链接（可访问性） */
.skip-link {
  position: absolute; left: 16px; top: -60px; z-index: 2000;
  background: var(--c-primary); color: #fff; padding: 10px 18px;
  border-radius: 8px; font-size: 14px; transition: top .2s ease;
}
.skip-link:focus { top: 12px; color: #fff; }

/* ---------- 通用区块 ---------- */
.section { padding: 88px 0; }
.section-alt { background: var(--c-bg-alt); }

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 12.5px; font-weight: 600;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--c-primary); margin-bottom: 14px;
}
.eyebrow::before { content: ""; width: 22px; height: 2px; background: var(--c-primary); border-radius: 2px; }

.section-title {
  margin: 0 0 18px; font-size: 30px; line-height: 1.35;
  font-weight: 700; color: var(--c-ink); letter-spacing: -.01em;
}
.section-sub { max-width: 760px; margin: 0 auto 44px; text-align: center; color: var(--c-muted); font-size: 16.5px; }
.section-head { text-align: center; margin-bottom: 48px; }
.section-head .section-sub { margin-bottom: 0; }

.lead { font-size: 17px; max-width: 880px; margin: 0 auto 44px; text-align: center; color: var(--c-body); }
.lead strong { color: var(--c-primary); font-weight: 600; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 28px; border-radius: 10px; font-size: 15.5px; font-weight: 600;
  border: 1px solid transparent; cursor: pointer; transition: all .2s ease;
  font-family: inherit; line-height: 1.4;
}
.btn-primary { background: var(--c-primary); color: #fff; box-shadow: 0 6px 18px rgba(32, 100, 230, .32); }
.btn-primary:hover { background: var(--c-primary-dark); color: #fff; transform: translateY(-2px); box-shadow: 0 10px 24px rgba(32, 100, 230, .38); }
.btn-ghost { background: transparent; color: #fff; border-color: rgba(255, 255, 255, .38); }
.btn-ghost:hover { border-color: #fff; background: rgba(255, 255, 255, .08); color: #fff; }
.btn-outline { background: #fff; color: var(--c-primary); border-color: var(--c-line); }
.btn-outline:hover { border-color: var(--c-primary); color: var(--c-primary-dark); }
.btn-lg { padding: 14px 36px; font-size: 16.5px; border-radius: 12px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(10, 19, 34, .82);
  -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }

.brand { display: flex; align-items: center; gap: 10px; font-size: 18px; font-weight: 700; color: #fff; }
.brand img { height: 30px; width: 30px; border-radius: 6px; }
.brand:hover { color: #fff; }

.nav { display: flex; align-items: center; gap: 30px; }
.nav a { color: rgba(255, 255, 255, .78); font-size: 15px; font-weight: 500; transition: color .2s ease; position: relative; }
.nav a:hover { color: #fff; }
.nav a::after {
  content: ""; position: absolute; left: 0; bottom: -6px; height: 2px; width: 0;
  background: linear-gradient(90deg, var(--c-primary), var(--c-cyan)); transition: width .25s ease; border-radius: 2px;
}
.nav a:hover::after { width: 100%; }

.header-cta { display: flex; align-items: center; gap: 12px; }
.header-cta .btn { padding: 9px 20px; font-size: 14.5px; }

.menu-btn {
  display: none; background: none; border: none; padding: 8px; cursor: pointer;
  color: #fff; line-height: 0; border-radius: 8px;
}
.menu-btn svg { width: 24px; height: 24px; stroke: currentColor; fill: none; stroke-width: 2; stroke-linecap: round; }
.menu-btn:focus-visible, .nav a:focus-visible, .btn:focus-visible { outline: 2px solid #7fb0ff; outline-offset: 2px; }

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  padding: 168px 0 132px; text-align: center; color: #fff;
  background:
    radial-gradient(720px 380px at 12% 0%, rgba(32, 100, 230, .38), transparent 62%),
    radial-gradient(620px 340px at 88% 16%, rgba(6, 182, 212, .26), transparent 60%),
    linear-gradient(178deg, var(--c-dark) 0%, var(--c-dark-2) 100%);
}
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .05) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: radial-gradient(ellipse 90% 70% at 50% 32%, #000 26%, transparent 78%);
  mask-image: radial-gradient(ellipse 90% 70% at 50% 32%, #000 26%, transparent 78%);
}
.hero-inner { position: relative; max-width: 880px; margin: 0 auto; }

.hero-badge {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 7px 18px; border-radius: 999px; margin-bottom: 26px;
  border: 1px solid rgba(255, 255, 255, .18); background: rgba(255, 255, 255, .06);
  font-size: 13.5px; color: rgba(255, 255, 255, .88); letter-spacing: .02em;
}
.hero-badge .dot { width: 7px; height: 7px; border-radius: 50%; background: #34d399; box-shadow: 0 0 0 4px rgba(52, 211, 153, .18); }

.hero h1 {
  margin: 0 0 20px; font-size: 46px; line-height: 1.24; font-weight: 700; letter-spacing: -.015em;
}
.hero h1 em { font-style: normal; background: linear-gradient(92deg, #6ea8ff, #37d6f0); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-sub { margin: 0 auto 36px; max-width: 640px; font-size: 18px; line-height: 1.8; color: rgba(255, 255, 255, .74); }
.hero-cta { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }

/* ---------- 统计条（叠在 hero 底边） ---------- */
.stats-wrap { position: relative; z-index: 5; margin-top: -72px; padding: 0 24px; }
.stats {
  max-width: 1000px; margin: 0 auto; display: grid; grid-template-columns: repeat(4, 1fr);
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius);
  box-shadow: var(--shadow-lg); overflow: hidden;
}
.stat { padding: 28px 16px; text-align: center; border-right: 1px solid var(--c-line); }
.stat:last-child { border-right: none; }
.stat-num {
  display: block; font-family: var(--mono); font-size: 34px; font-weight: 700;
  color: var(--c-primary); line-height: 1.15; letter-spacing: -.02em;
}
.stat-label { display: block; margin-top: 6px; font-size: 13.5px; color: var(--c-muted); }

/* ---------- 关键事实卡 ---------- */
.facts-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
  margin: 0 auto; max-width: 1000px; padding: 0;
}
.fact {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius-sm);
  padding: 18px 20px; transition: border-color .2s ease, box-shadow .2s ease;
}
.fact:hover { border-color: rgba(32, 100, 230, .45); box-shadow: var(--shadow-md); }
.fact dt { font-size: 12.5px; color: var(--c-muted); margin-bottom: 5px; letter-spacing: .03em; }
.fact dd { margin: 0; font-size: 15.5px; font-weight: 600; color: var(--c-ink); line-height: 1.5; }

/* ---------- 能力卡 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.card {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: 30px 26px; transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: rgba(32, 100, 230, .4); }
.card-icon {
  width: 52px; height: 52px; border-radius: 13px; margin-bottom: 18px;
  display: flex; align-items: center; justify-content: center;
  background: var(--c-primary-soft); color: var(--c-primary);
}
.card-icon svg { width: 26px; height: 26px; stroke: currentColor; fill: none; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.card h3 { margin: 0 0 10px; font-size: 18.5px; font-weight: 600; color: var(--c-ink); }
.card p { margin: 0; font-size: 14.5px; color: var(--c-muted); line-height: 1.75; }

/* ---------- 表格 ---------- */
.table-wrap {
  max-width: 1060px; margin: 0 auto; background: #fff;
  border: 1px solid var(--c-line); border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.table-scroll { overflow-x: auto; }
table.data-table { width: 100%; border-collapse: collapse; font-size: 14.5px; min-width: 640px; }
.data-table caption { text-align: left; padding: 16px 22px 0; font-size: 12.5px; color: var(--c-muted); }
.data-table thead th {
  background: #f1f5fd; color: #29497e; font-weight: 600; text-align: left;
  padding: 13px 20px; border-bottom: 1px solid #dbe6f6; white-space: nowrap; font-size: 13.5px;
}
.data-table td { padding: 13px 20px; border-bottom: 1px solid #eef2f7; vertical-align: top; line-height: 1.65; color: var(--c-body); }
.data-table tbody tr:last-child td { border-bottom: none; }
.data-table tbody tr:nth-child(even) { background: #fbfcfe; }
.data-table td:first-child { color: var(--c-ink); font-weight: 500; }
.table-note { max-width: 1060px; margin: 14px auto 0; font-size: 13px; color: var(--c-muted); line-height: 1.7; }

/* ---------- API 示例 ---------- */
.api-grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: 44px; align-items: center; max-width: 1060px; margin: 0 auto; }
.api-side h3 { margin: 0 0 12px; font-size: 21px; font-weight: 600; color: var(--c-ink); }
.api-side > p { margin: 0 0 20px; font-size: 15px; color: var(--c-muted); }
.api-points { list-style: none; margin: 0 0 26px; padding: 0; }
.api-points li { position: relative; padding: 7px 0 7px 30px; font-size: 15px; color: var(--c-body); }
.api-points li::before {
  content: ""; position: absolute; left: 2px; top: 15px; width: 16px; height: 16px;
  border-radius: 50%; background: var(--c-primary-soft);
  box-shadow: inset 0 0 0 1.5px rgba(32, 100, 230, .5);
}
.api-points li::after { content: ""; position: absolute; left: 7.5px; top: 20px; width: 5px; height: 6px; border-right: 2px solid var(--c-primary); border-bottom: 2px solid var(--c-primary); transform: rotate(40deg); }

.code-card {
  background: #0d1526; border-radius: var(--radius); overflow: hidden;
  border: 1px solid #1d2c47; box-shadow: var(--shadow-lg);
}
.code-card + .code-card { margin-top: 18px; }
.code-head {
  display: flex; align-items: center; gap: 12px; padding: 12px 18px;
  background: #111c33; border-bottom: 1px solid #1d2c47;
}
.dots { display: inline-flex; gap: 6px; }
.dots i { width: 11px; height: 11px; border-radius: 50%; display: block; }
.dots i:nth-child(1) { background: #ff5f57; }
.dots i:nth-child(2) { background: #febc2e; }
.dots i:nth-child(3) { background: #28c840; }
.code-title { font-family: var(--mono); font-size: 12.5px; color: #8fa3c4; letter-spacing: .02em; }
.code-body { margin: 0; padding: 18px 20px; overflow-x: auto; font-family: var(--mono); font-size: 13px; line-height: 1.85; color: #c9d6ec; }
.code-body .k { color: #79b8ff; }        /* 键名 */
.code-body .s { color: #9ecbff; }        /* 字符串 */
.code-body .n { color: #f2cc60; }        /* 数字 */
.code-body .c { color: #5b708f; }        /* 注释 */
.code-body .m { color: #7ee787; }        /* 方法/成功 */
.code-body .u { color: #56d4dd; }        /* URL */

/* ---------- 应用场景 ---------- */
.scene-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.scene { background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius); overflow: hidden; transition: transform .22s ease, box-shadow .22s ease; }
.scene:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.scene-img { height: 180px; overflow: hidden; background: #eef2f7; }
.scene-img img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s ease; }
.scene:hover .scene-img img { transform: scale(1.05); }
.scene-body { padding: 20px 22px; }
.scene-body h3 { margin: 0 0 8px; font-size: 18px; font-weight: 600; color: var(--c-ink); }
.scene-body p { margin: 0; font-size: 14px; color: var(--c-muted); line-height: 1.7; }

/* ---------- 产品优势 ---------- */
.benefit-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; max-width: 1060px; margin: 0 auto; }
.benefit {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: 26px 24px; transition: border-color .2s ease, box-shadow .2s ease;
}
.benefit:hover { border-color: rgba(32, 100, 230, .45); box-shadow: var(--shadow-md); }
.benefit-num {
  font-family: var(--mono); font-size: 13px; font-weight: 700; color: var(--c-primary);
  letter-spacing: .1em; margin-bottom: 14px;
  display: inline-flex; align-items: center; gap: 10px;
}
.benefit-num::after { content: ""; width: 26px; height: 2px; background: var(--c-primary-soft); border-radius: 2px; }
.benefit h3 { margin: 0 0 8px; font-size: 17.5px; font-weight: 600; color: var(--c-ink); }
.benefit p { margin: 0; font-size: 14px; color: var(--c-muted); line-height: 1.7; }

/* ---------- 客户评价 ---------- */
.quotes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; max-width: 1060px; margin: 0 auto; }
.quote { background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius); padding: 28px 26px; position: relative; }
.quote::before {
  content: ""; position: absolute; top: 20px; right: 24px; width: 34px; height: 26px;
  background: var(--c-primary-soft); border-radius: 6px;
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 18'%3E%3Cpath d='M2 12c0-5 3-9 8-10l1 2C8 5.5 6.5 7.5 6.5 9.5H10V16H2v-4zm12 0c0-5 3-9 8-10l1 2c-3 1.5-4.5 3.5-4.5 5.5H22V16h-8v-4z'/%3E%3C/svg%3E") center / contain no-repeat;
  mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 18'%3E%3Cpath d='M2 12c0-5 3-9 8-10l1 2C8 5.5 6.5 7.5 6.5 9.5H10V16H2v-4zm12 0c0-5 3-9 8-10l1 2c-3 1.5-4.5 3.5-4.5 5.5H22V16h-8v-4z'/%3E%3C/svg%3E") center / contain no-repeat;
}
.quote-text { margin: 0 0 20px; font-size: 15px; line-height: 1.85; color: var(--c-body); }
.quote-author { display: flex; align-items: center; gap: 12px; }
.avatar { width: 44px; height: 44px; border-radius: 50%; overflow: flex; overflow: hidden; border: 2px solid var(--c-primary-soft); }
.avatar img { width: 100%; height: 100%; object-fit: cover; }
.quote-author h3 { margin: 0; font-size: 15px; font-weight: 600; color: var(--c-ink); }
.quote-author p { margin: 0; font-size: 13px; color: var(--c-muted); }

/* ---------- FAQ ---------- */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius-sm);
  padding: 22px 26px; margin-bottom: 14px; transition: border-color .2s ease;
}
.faq:hover { border-color: rgba(32, 100, 230, .4); }
.faq h3 { margin: 0 0 8px; font-size: 16.5px; font-weight: 600; color: var(--c-ink); line-height: 1.55; }
.faq p { margin: 0; font-size: 14.5px; color: var(--c-body); line-height: 1.8; }
.faq p + p { margin-top: 8px; }

/* ---------- 实体信息（dt/dd 按对包裹在 div 里，避免多列栅格把键值打散） ---------- */
.entity-grid { max-width: 1000px; margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.entity-grid > div {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius-sm);
  padding: 18px 20px; transition: border-color .2s ease, box-shadow .2s ease;
}
.entity-grid > div:hover { border-color: rgba(32, 100, 230, .45); box-shadow: var(--shadow-md); }
.entity-grid dt { font-size: 12.5px; color: var(--c-muted); margin: 0; }
.entity-grid dd { margin: 5px 0 0; font-size: 15.5px; font-weight: 500; color: var(--c-ink); overflow-wrap: anywhere; }

/* ---------- 联系我们 ---------- */
.contact-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; max-width: 900px; margin: 0 auto 36px; }
.contact-card {
  background: #fff; border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: 28px 22px; text-align: center; transition: border-color .2s ease, box-shadow .2s ease;
}
.contact-card:hover { border-color: rgba(32, 100, 230, .45); box-shadow: var(--shadow-md); }
.contact-card .card-icon { margin: 0 auto 14px; border-radius: 50%; }
.contact-card h3 { margin: 0 0 6px; font-size: 16.5px; font-weight: 600; color: var(--c-ink); }
.contact-card p { margin: 0; font-size: 15px; color: var(--c-body); }
.contact-cta { text-align: center; }

/* ---------- CTA 横幅 ---------- */
.cta-banner {
  position: relative; overflow: hidden; text-align: center; color: #fff;
  padding: 76px 24px;
  background:
    radial-gradient(560px 300px at 20% 0%, rgba(32, 100, 230, .4), transparent 62%),
    radial-gradient(480px 280px at 82% 100%, rgba(6, 182, 212, .3), transparent 60%),
    linear-gradient(178deg, var(--c-dark-2), var(--c-dark));
}
.cta-banner h2 { margin: 0 0 14px; font-size: 30px; font-weight: 700; letter-spacing: -.01em; }
.cta-banner p { margin: 0 auto 30px; max-width: 560px; color: rgba(255, 255, 255, .72); font-size: 16px; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--c-dark); color: rgba(255, 255, 255, .68); padding: 64px 0 0; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: 40px; padding-bottom: 44px; }
.footer-brand img { height: 34px; width: 34px; border-radius: 8px; margin-bottom: 14px; }
.footer-brand .brand-name { color: #fff; font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.footer-brand p { margin: 0; line-height: 1.8; max-width: 300px; }
.footer-col h3 { margin: 4px 0 16px; font-size: 14.5px; font-weight: 600; color: #fff; letter-spacing: .02em; }
.footer-col ul { list-style: none; margin: 0; padding: 0; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { color: rgba(255, 255, 255, .62); transition: color .2s ease; }
.footer-col a:hover { color: #fff; }
.footer-col p { margin: 0 0 10px; }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, .09); padding: 20px 0 26px; text-align: center; font-size: 13px; color: rgba(255, 255, 255, .45); }
.footer-bottom a { color: rgba(255, 255, 255, .45); }
.footer-bottom a:hover { color: rgba(255, 255, 255, .8); }

/* ---------- 弹窗 ---------- */
.modal-overlay {
  position: fixed; inset: 0; z-index: 1500;
  background: rgba(10, 19, 34, .72);
  -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px);
  display: flex; justify-content: center; align-items: center;
  opacity: 0; visibility: hidden; transition: opacity .25s ease, visibility .25s ease;
}
.modal-overlay.active { opacity: 1; visibility: visible; }
.modal {
  background: #fff; border-radius: 18px; width: 90%; max-width: 400px;
  box-shadow: var(--shadow-lg); transform: scale(.92); transition: transform .28s ease; overflow: hidden;
}
.modal-overlay.active .modal { transform: scale(1); }
.modal-header { display: flex; align-items: center; justify-content: space-between; padding: 18px 24px; border-bottom: 1px solid var(--c-line); }
.modal-title { margin: 0; font-size: 18px; font-weight: 600; color: var(--c-ink); }
.close-btn {
  background: none; border: none; font-size: 26px; line-height: 1; cursor: pointer;
  color: var(--c-muted); width: 38px; height: 38px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; transition: background .2s ease, color .2s ease;
}
.close-btn:hover { background: var(--c-bg-alt); color: var(--c-ink); }
.modal-body { padding: 26px 24px; display: flex; justify-content: center; }
.qrcode-box { padding: 14px; border: 1px solid var(--c-line); border-radius: 14px; }
.modal-footer { padding: 14px 24px 22px; text-align: center; font-size: 13.5px; color: var(--c-muted); border-top: 1px solid var(--c-line); }
.modal-footer p { margin: 0; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .facts-grid { grid-template-columns: repeat(2, 1fr); }
  .grid-3, .scene-grid, .quotes { grid-template-columns: repeat(2, 1fr); }
  .benefit-row { grid-template-columns: repeat(2, 1fr); }
  .entity-grid { grid-template-columns: repeat(2, 1fr); }
  .api-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .section { padding: 60px 0; }
  .hero { padding: 140px 0 110px; }
  .hero h1 { font-size: 32px; }
  .hero-sub { font-size: 16px; }
  .section-title { font-size: 25px; }

  .nav {
    display: none; flex-direction: column; align-items: stretch; gap: 0;
    position: absolute; top: 100%; left: 0; right: 0;
    background: var(--c-dark); border-bottom: 1px solid rgba(255, 255, 255, .1);
    padding: 8px 24px 14px;
  }
  .nav.open { display: flex; }
  .nav a { padding: 13px 0; border-bottom: 1px solid rgba(255, 255, 255, .07); font-size: 15.5px; }
  .nav a:last-child { border-bottom: none; }
  .nav a::after { display: none; }
  .menu-btn { display: inline-flex; align-items: center; justify-content: center; }

  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(2) { border-right: none; }
  .stat:nth-child(1), .stat:nth-child(2) { border-bottom: 1px solid var(--c-line); }
  .stats-wrap { margin-top: -56px; }

  .grid-3, .scene-grid, .quotes, .contact-cards, .facts-grid, .benefit-row { grid-template-columns: 1fr; }
  .entity-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .stat-num { font-size: 28px; }
}

@media (max-width: 480px) {
  .container { padding: 0 18px; }
  .hero { padding: 120px 0 100px; }
  .hero h1 { font-size: 27px; }
  .hero-cta .btn { width: 100%; }
  .btn { padding: 12px 22px; }
  .section { padding: 52px 0; }
}

/* ---------- 返回顶部 ---------- */
.back-top {
  position: fixed; right: 28px; bottom: 32px; z-index: 900;
  width: 46px; height: 46px; border-radius: 50%;
  background: rgba(10, 19, 34, .86);
  -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, .16); color: #fff;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; padding: 0; line-height: 0;
  box-shadow: 0 8px 24px rgba(15, 23, 42, .28);
  opacity: 0; visibility: hidden; transform: translateY(12px);
  transition: opacity .25s ease, visibility .25s ease, transform .25s ease, border-color .2s ease;
}
.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-top:hover { border-color: var(--c-primary); color: #fff; transform: translateY(-3px); }
.back-top:focus-visible { outline: 2px solid #7fb0ff; outline-offset: 2px; }
.back-top svg { width: 22px; height: 22px; stroke: currentColor; fill: none; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }

@media (max-width: 768px) {
  .back-top { right: 16px; bottom: 20px; width: 42px; height: 42px; }
}

/* 减少动效偏好（可访问性规范） */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
  html { scroll-behavior: auto; }
}