/* ==========================================================================
   企数链（深圳）数据科技有限公司 — 品牌官网样式
   设计系统：深海蓝 + 电光蓝 + 数据青，数据链路为视觉母题
   ========================================================================== */

/* ---------- 设计令牌 ---------- */
:root {
  --c-navy: #0A1B3D;
  --c-navy-2: #0E244D;
  --c-navy-3: #12305f;
  --c-blue: #1D5BFF;
  --c-blue-2: #4D82FF;
  --c-cyan: #35D0FF;
  --c-bg: #F5F8FC;
  --c-bg-2: #FFFFFF;
  --c-ink: #0B1B33;
  --c-muted: #56657F;
  --c-muted-2: #7E96BD;
  --c-line: #E3EAF4;
  --c-success: #17B26A;
  --c-danger: #E5484D;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;

  --shadow-sm: 0 1px 2px rgba(10, 27, 61, 0.05);
  --shadow-md: 0 8px 30px rgba(10, 27, 61, 0.08);
  --shadow-lg: 0 20px 50px rgba(10, 27, 61, 0.14);

  --container: 1180px;
  --header-h: 72px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- 基础重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-muted);
  background: var(--c-bg-2);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 { color: var(--c-ink); margin: 0; line-height: 1.25; font-weight: 700; }
p { margin: 0; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
button { font-family: inherit; cursor: pointer; }
ul, ol { margin: 0; padding: 0; list-style: none; }
figure { margin: 0; }
blockquote { margin: 0; }

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 24px;
}

:focus-visible {
  outline: 3px solid var(--c-blue);
  outline-offset: 2px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 200;
  background: var(--c-blue);
  color: #fff;
  padding: 10px 18px;
  border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 15px;
  line-height: 1;
  padding: 13px 24px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease),
    background-color 0.25s var(--ease), border-color 0.25s var(--ease), color 0.25s var(--ease);
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }

.btn-primary {
  background: linear-gradient(135deg, var(--c-blue), #2f6bff);
  color: #fff;
  box-shadow: 0 8px 22px rgba(29, 91, 255, 0.32);
}
.btn-primary:hover { background: linear-gradient(135deg, #1651e8, #1d5bff); box-shadow: 0 12px 28px rgba(29, 91, 255, 0.4); }

.btn-ghost {
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.24);
}
.btn-ghost:hover { background: rgba(255, 255, 255, 0.12); border-color: rgba(255, 255, 255, 0.4); }

.btn-outline {
  background: transparent;
  color: var(--c-blue);
  border-color: var(--c-blue);
}
.btn-outline:hover { background: rgba(29, 91, 255, 0.06); }

.btn-sm { padding: 10px 18px; font-size: 14px; }
.btn-lg { padding: 16px 32px; font-size: 16px; }
.btn-block { width: 100%; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-h);
  transition: background-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.site-header.is-scrolled {
  background: rgba(10, 27, 61, 0.92);
  backdrop-filter: saturate(180%) blur(14px);
  box-shadow: 0 8px 30px rgba(5, 14, 33, 0.35);
}
.header-inner {
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand { display: inline-flex; align-items: center; gap: 10px; color: #fff; }
.brand-mark { color: var(--c-cyan); display: flex; }
.brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.brand-text strong { font-size: 18px; letter-spacing: 0.5px; }
.brand-text em { font-style: normal; font-size: 10px; letter-spacing: 1.5px; color: var(--c-muted-2); }

.main-nav { display: flex; align-items: center; gap: 6px; margin-left: auto; }
.nav-link {
  color: rgba(255, 255, 255, 0.82);
  font-size: 15px;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  transition: color 0.2s, background-color 0.2s;
}
.nav-link:hover { color: #fff; background: rgba(255, 255, 255, 0.08); }
.nav-link.is-active { color: #fff; background: rgba(255, 255, 255, 0.1); }

.header-actions { display: flex; align-items: center; gap: 14px; }
.header-phone {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #fff;
  font-weight: 600;
  font-size: 15px;
  font-variant-numeric: tabular-nums;
  transition: color 0.2s;
}
.header-phone svg { color: var(--c-cyan); }
.header-phone:hover { color: var(--c-cyan); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 42px;
  height: 42px;
  padding: 10px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 10px;
}
.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: #fff;
  border-radius: 2px;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- HERO ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(1100px 600px at 78% -10%, rgba(29, 91, 255, 0.35), transparent 60%),
    radial-gradient(900px 500px at -10% 110%, rgba(53, 208, 255, 0.18), transparent 55%),
    linear-gradient(160deg, #060f24 0%, var(--c-navy) 45%, var(--c-navy-2) 100%);
  color: #fff;
  padding: calc(var(--header-h) + 64px) 0 72px;
}
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 90% 80% at 50% 0%, #000 40%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 90% 80% at 50% 0%, #000 40%, transparent 100%);
}
.hero-glow {
  position: absolute;
  top: -120px;
  right: -80px;
  width: 520px;
  height: 520px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(53, 208, 255, 0.16), transparent 70%);
  filter: blur(10px);
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 40px;
  align-items: center;
  padding-bottom: 64px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--c-blue);
  margin-bottom: 18px;
}
.eyebrow .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-blue);
}
.eyebrow-light { color: var(--c-cyan); }
.eyebrow-light .dot { background: var(--c-cyan); }

.hero-title {
  font-size: clamp(2.1rem, 4.6vw, 3.55rem);
  font-weight: 800;
  letter-spacing: -0.5px;
  line-height: 1.18;
  color: #fff;
}
.accent-underline {
  position: relative;
  z-index: 0;
  color: var(--c-cyan);
  white-space: nowrap;
}
.accent-underline::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.06em;
  height: 0.32em;
  background: linear-gradient(90deg, var(--c-cyan), rgba(53, 208, 255, 0));
  opacity: 0.35;
  border-radius: 2px;
  z-index: -1;
}

.hero-sub {
  margin-top: 22px;
  font-size: 17px;
  line-height: 1.9;
  color: rgba(255, 255, 255, 0.72);
  max-width: 560px;
}
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 34px; }

.hero-visual { position: relative; }
.dataflow { width: 100%; height: auto; }

/* 数据指标 */
.stats-band {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.09);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(8px);
  overflow: hidden;
}
.stat {
  padding: 30px 26px;
  border-left: 1px solid rgba(255, 255, 255, 0.08);
}
.stat:first-child { border-left: none; }
.stat-num {
  display: block;
  font-size: 40px;
  font-weight: 800;
  color: #fff;
  font-variant-numeric: tabular-nums;
  letter-spacing: -1px;
}
.stat-num em { font-style: normal; color: var(--c-cyan); }
.stat-label { display: block; margin-top: 6px; font-size: 15px; font-weight: 600; color: #fff; }
.stat-note { display: block; margin-top: 4px; font-size: 12.5px; color: var(--c-muted-2); }

/* ---------- 章节通用 ---------- */
.section { padding: 96px 0; }
.section-alt { background: var(--c-bg); }
.section-dark {
  background:
    radial-gradient(900px 500px at 90% 10%, rgba(29, 91, 255, 0.22), transparent 60%),
    linear-gradient(160deg, var(--c-navy) 0%, var(--c-navy-2) 100%);
  color: rgba(255, 255, 255, 0.72);
}

.section-head { max-width: 640px; margin-bottom: 54px; }
.section-head-row { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; max-width: none; }
.section-head-row .btn { margin-bottom: 4px; }
.section-title { font-size: clamp(1.7rem, 3vw, 2.4rem); letter-spacing: -0.5px; }
.title-light { color: #fff; }
.section-lead { margin-top: 16px; font-size: 16.5px; }
.section-foot { text-align: center; margin-top: 46px; }

/* ---------- 卡片网格 ---------- */
.card-grid { display: grid; gap: 24px; }
.cols-4 { grid-template-columns: repeat(4, 1fr); }
.cols-3 { grid-template-columns: repeat(3, 1fr); }

/* ---------- 核心业务卡片 ---------- */
.service-card {
  position: relative;
  background: var(--c-bg-2);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-md);
  padding: 34px 28px 30px;
  overflow: hidden;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}
.service-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-blue), var(--c-cyan));
  opacity: 0;
  transition: opacity 0.3s var(--ease);
}
.service-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: transparent; }
.service-card:hover::before { opacity: 1; }
.card-index {
  position: absolute;
  top: 20px;
  right: 22px;
  font-size: 40px;
  font-weight: 800;
  line-height: 1;
  color: #eef3fb;
  letter-spacing: -1px;
}
.card-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(29, 91, 255, 0.1), rgba(53, 208, 255, 0.14));
  color: var(--c-blue);
  margin-bottom: 20px;
}
.card-title { font-size: 18px; margin-bottom: 12px; }
.card-text { font-size: 14.5px; }
.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--c-blue);
  transition: gap 0.25s var(--ease);
}
.card-link:hover { gap: 10px; }

/* ---------- 方法论 ---------- */
.steps { display: grid; gap: 0; counter-reset: step; }
.step {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 22px;
  padding: 26px 0;
  border-top: 1px solid var(--c-line);
}
.step:last-child { border-bottom: 1px solid var(--c-line); }
.step-num {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--c-blue), #2f6bff);
  color: #fff;
  font-size: 22px;
  font-weight: 800;
  box-shadow: 0 8px 20px rgba(29, 91, 255, 0.26);
}
.step-title { font-size: 19px; }
.step-sub { margin-top: 8px; font-weight: 600; color: var(--c-ink); font-size: 15px; }
.step-text { margin-top: 8px; font-size: 14.5px; }

/* ---------- 案例卡片 ---------- */
.case-card {
  display: flex;
  flex-direction: column;
  background: var(--c-bg-2);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-md);
  padding: 30px 28px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.case-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.case-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 18px; }
.case-tag {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--c-blue);
  background: rgba(29, 91, 255, 0.08);
  padding: 5px 12px;
  border-radius: var(--radius-pill);
}
.case-client { font-size: 13px; color: var(--c-muted-2); }
.case-title { font-size: 18px; margin-bottom: 12px; }
.case-text { font-size: 14.5px; margin-bottom: 20px; }
.case-metrics { display: grid; gap: 12px; margin: 0 0 22px; padding: 0; }
.case-metrics div { display: flex; justify-content: space-between; gap: 12px; padding-bottom: 10px; border-bottom: 1px dashed var(--c-line); }
.case-metrics div:last-child { border-bottom: none; }
.case-metrics dt { font-size: 13.5px; color: var(--c-muted); }
.case-metrics dd { margin: 0; font-size: 14px; font-weight: 700; color: var(--c-ink); text-align: right; }
.case-type {
  margin-top: auto;
  align-self: flex-start;
  font-size: 13px;
  font-weight: 600;
  color: var(--c-blue);
}

/* ---------- 关于我们 ---------- */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.about-lead { font-size: 16.5px; line-height: 2; margin: 22px 0 30px; }
.about-pillars { display: grid; gap: 16px; }
.pillar {
  display: flex;
  gap: 18px;
  padding: 22px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.09);
  border-radius: var(--radius-md);
  transition: background-color 0.3s, border-color 0.3s;
}
.pillar:hover { background: rgba(255, 255, 255, 0.07); border-color: rgba(53, 208, 255, 0.3); }
.pillar-icon {
  flex: none;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: rgba(53, 208, 255, 0.1);
  color: var(--c-cyan);
}
.pillar-title { color: #fff; font-size: 17px; margin-bottom: 8px; }
.pillar-text { font-size: 14px; }

/* ---------- 新闻卡片 ---------- */
.news-card {
  display: flex;
  flex-direction: column;
  background: var(--c-bg-2);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.news-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.news-meta { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 16px; }
.news-cat {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--c-blue);
  background: rgba(29, 91, 255, 0.08);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
}
.news-cat-alt { color: #0aa06f; background: rgba(23, 178, 106, 0.1); }
.news-meta time { font-size: 13px; color: var(--c-muted-2); font-variant-numeric: tabular-nums; }
.news-title { font-size: 17.5px; margin-bottom: 12px; }
.news-text { font-size: 14px; }
.news-card .card-link { margin-top: auto; padding-top: 18px; }

/* ---------- FAQ ---------- */
.faq-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 56px; align-items: start; }
.faq-list { display: grid; gap: 14px; }
.faq-item {
  background: var(--c-bg-2);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.25s;
}
.faq-item.open { border-color: rgba(29, 91, 255, 0.4); }
.faq-q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  padding: 20px 22px;
  background: none;
  border: none;
  text-align: left;
  font-size: 16px;
  font-weight: 600;
  color: var(--c-ink);
}
.faq-q svg { flex: none; color: var(--c-blue); transition: transform 0.3s var(--ease); }
.faq-item.open .faq-q svg { transform: rotate(45deg); }
.faq-a { padding: 0 22px 20px; }
.faq-a p { font-size: 14.5px; }

/* ---------- 客户评价 ---------- */
.quote-card {
  display: flex;
  flex-direction: column;
  gap: 22px;
  background: var(--c-bg-2);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-md);
  padding: 30px 28px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.quote-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.quote-card blockquote {
  position: relative;
  font-size: 15px;
  line-height: 1.9;
  color: var(--c-ink);
}
.quote-card blockquote::before {
  content: "“";
  position: absolute;
  top: -18px;
  left: -4px;
  font-size: 56px;
  line-height: 1;
  color: var(--c-blue);
  opacity: 0.2;
  font-family: Georgia, serif;
}
.quote-card figcaption { display: flex; align-items: center; gap: 12px; }
.avatar {
  flex: none;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--c-blue), var(--c-cyan));
  color: #fff;
  font-weight: 700;
  font-size: 16px;
}
.quote-card figcaption div { display: flex; flex-direction: column; }
.quote-card figcaption strong { color: var(--c-ink); font-size: 14.5px; }
.quote-card figcaption em { font-style: normal; font-size: 13px; color: var(--c-muted-2); }

/* ---------- 联系我们 ---------- */
.section-contact { background: var(--c-bg); }
.section-contact .section-head { text-align: center; margin-inline: auto; }
.contact-info {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 840px;
  margin-inline: auto;
}
.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--c-bg-2);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-md);
  padding: 26px 24px;
  transition: border-color 0.25s, box-shadow 0.25s;
}
.contact-item:hover { border-color: rgba(29, 91, 255, 0.3); box-shadow: var(--shadow-sm); }
.contact-icon {
  flex: none;
  width: 46px;
  height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--c-bg);
  color: var(--c-blue);
}
.contact-item div { display: flex; flex-direction: column; }
.contact-label { font-size: 13px; color: var(--c-muted-2); }
.contact-value { font-size: 17px; font-weight: 700; color: var(--c-ink); margin-top: 2px; overflow-wrap: anywhere; }
a.contact-value:hover { color: var(--c-blue); }

/* ---------- 页脚 ---------- */
.site-footer { background: #060f24; color: rgba(255, 255, 255, 0.62); }
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr 1fr 1fr;
  gap: 40px;
  padding: 64px 24px 48px;
}
.brand-inverse .brand-text strong { color: #fff; }
.footer-desc { margin-top: 20px; font-size: 14px; max-width: 340px; }
.footer-tagline { margin-top: 18px; font-size: 15px; font-weight: 600; color: var(--c-cyan); }
.footer-col { display: flex; flex-direction: column; gap: 10px; }
.footer-col h4 { color: #fff; font-size: 15px; margin-bottom: 8px; }
.footer-col a, .footer-col span { font-size: 14px; color: rgba(255, 255, 255, 0.62); transition: color 0.2s; }
.footer-col a:hover { color: var(--c-cyan); }
.footer-cta {
  margin-top: 8px;
  align-self: flex-start;
  color: #fff !important;
  background: linear-gradient(135deg, var(--c-blue), #2f6bff);
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  font-weight: 600;
}
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding: 22px 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 13px;
}

/* ---------- 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 90;
  width: 46px;
  height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  border-radius: 50%;
  background: var(--c-blue);
  color: #fff;
  box-shadow: 0 10px 24px rgba(29, 91, 255, 0.36);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.3s, transform 0.3s, visibility 0.3s;
}
.back-to-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: #1651e8; }

/* ---------- 滚动显现动画 ---------- */
.js .reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.js .reveal.in-view { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .cols-4 { grid-template-columns: repeat(2, 1fr); }
  .hero-inner { grid-template-columns: 1fr; }
  .hero-visual { max-width: 520px; margin-inline: auto; }
  .about-grid, .faq-grid { grid-template-columns: 1fr; gap: 40px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 760px) {
  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: rgba(10, 27, 61, 0.98);
    backdrop-filter: blur(14px);
    padding: 12px 20px 20px;
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.3s var(--ease), opacity 0.3s var(--ease), visibility 0.3s;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  .main-nav.is-open { transform: none; opacity: 1; visibility: visible; }
  .nav-link { padding: 13px 14px; font-size: 16px; }
  .nav-toggle { display: flex; }
  .header-phone span { display: none; }
  .header-phone { padding: 10px; border-radius: 10px; background: rgba(255, 255, 255, 0.08); }
  .header-actions .btn { display: none; }

  .stats-band { grid-template-columns: repeat(2, 1fr); }
  .stat { padding: 24px 20px; }
  .stat:nth-child(3) { border-left: none; }
  .stat:nth-child(n+3) { border-top: 1px solid rgba(255, 255, 255, 0.08); }
  .stat-num { font-size: 32px; }

  .section { padding: 64px 0; }
  .cols-3, .cols-4 { grid-template-columns: 1fr; }
  .section-head-row { flex-direction: column; align-items: flex-start; }
  .step { grid-template-columns: 52px 1fr; gap: 16px; }
  .step-num { width: 46px; height: 46px; font-size: 19px; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { justify-content: center; text-align: center; }
  .contact-info { grid-template-columns: 1fr; }
}

/* ---------- 无障碍：减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .reveal, .js .reveal { opacity: 1; transform: none; }
  .dataflow .flow-line { display: none; }
}