/* ============================================================
   武汉常量数据科技有限公司 · 企业官网
   全局样式 · 简约大气
   ============================================================ */

:root {
  /* 主色：科技深蓝 */
  --c-navy: #0b1f3a;
  --c-navy-2: #12325c;
  --c-blue: #1b6ef3;
  --c-blue-soft: #e8f1ff;
  /* 品牌点缀：柚子绿 */
  --c-yuzu: #65c466;
  --c-yuzu-deep: #3fa85a;
  --c-yuzu-soft: #eaf7ec;
  /* 中性色 */
  --c-bg: #ffffff;
  --c-bg-alt: #f6f8fb;
  --c-bg-dark: #0b1f3a;
  --c-text: #1a2b45;
  --c-text-soft: #5b6b82;
  --c-line: #e6ebf2;
  /* 排版 */
  --maxw: 1200px;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 18px 50px -20px rgba(11, 31, 58, 0.25);
  --shadow-sm: 0 8px 24px -12px rgba(11, 31, 58, 0.18);
  --ff: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, "Segoe UI", Robn, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--ff);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===================== 顶部导航 ===================== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--c-line);
  transition: box-shadow .3s ease, background .3s ease;
}
.header.scrolled { box-shadow: var(--shadow-sm); }

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  font-weight: 800;
  font-size: 18px;
  letter-spacing: .3px;
}
.brand .logo {
  width: 38px; height: 38px;
  border-radius: 11px;
  background: linear-gradient(135deg, var(--c-blue), var(--c-yuzu));
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 19px;
  box-shadow: 0 8px 18px -8px rgba(27, 110, 243, .6);
}
.brand .brand-name { color: var(--c-navy); }
.brand .brand-sub { font-size: 12px; color: var(--c-text-soft); font-weight: 500; letter-spacing: 0; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-links a {
  padding: 9px 15px;
  border-radius: 9px;
  font-size: 15px;
  color: var(--c-text-soft);
  font-weight: 500;
  transition: color .2s, background .2s;
}
.nav-links a:hover { color: var(--c-navy); background: var(--c-bg-alt); }
.nav-links a.active { color: var(--c-blue); background: var(--c-blue-soft); }

.nav-cta {
  margin-left: 10px;
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--c-blue);
  color: #fff !important;
  font-weight: 600;
  font-size: 14px;
  box-shadow: 0 10px 22px -10px rgba(27, 110, 243, .7);
  transition: transform .2s, box-shadow .2s;
}
.nav-cta:hover { transform: translateY(-2px); box-shadow: 0 14px 26px -10px rgba(27, 110, 243, .8); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  width: 24px; height: 2px;
  background: var(--c-navy);
  border-radius: 2px;
  transition: .3s;
}

/* ===================== 通用区块 ===================== */
section { padding: 96px 0; }
.section-alt { background: var(--c-bg-alt); }
.section-dark {
  background: linear-gradient(160deg, var(--c-navy) 0%, var(--c-navy-2) 100%);
  color: #fff;
}

.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}
.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--c-yuzu-deep);
  text-transform: uppercase;
  margin-bottom: 14px;
}
.section-head h2 {
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 800;
  letter-spacing: -.5px;
  color: var(--c-navy);
  line-height: 1.25;
}
.section-head p {
  margin-top: 16px;
  color: var(--c-text-soft);
  font-size: 16px;
}
.section-dark .section-head h2,
.section-dark .section-head p { color: #fff; }
.section-dark .eyebrow { color: var(--c-yuzu); }

/* ===================== 按钮 ===================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform .2s, box-shadow .2s, background .2s;
}
.btn-primary {
  background: var(--c-blue);
  color: #fff;
  box-shadow: 0 12px 26px -12px rgba(27, 110, 243, .8);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 30px -12px rgba(27, 110, 243, .9); }
.btn-ghost {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, .35);
}
.btn-ghost:hover { background: rgba(255, 255, 255, .12); }
.btn-outline {
  background: #fff;
  color: var(--c-navy);
  border-color: var(--c-line);
}
.btn-outline:hover { border-color: var(--c-blue); color: var(--c-blue); }
.btn .arrow { transition: transform .2s; }
.btn:hover .arrow { transform: translateX(4px); }

/* ===================== 首页 Hero ===================== */
.hero {
  position: relative;
  padding: 150px 0 96px;
  background:
    radial-gradient(1200px 500px at 85% -10%, rgba(101, 196, 102, .18), transparent 60%),
    radial-gradient(900px 500px at 0% 0%, rgba(27, 110, 243, .14), transparent 55%),
    linear-gradient(180deg, #fbfcff 0%, #ffffff 100%);
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: 56px;
  align-items: center;
}
.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 15px;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--c-line);
  font-size: 13px;
  color: var(--c-text-soft);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
  margin-bottom: 22px;
}
.hero-tag .dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--c-yuzu);
  box-shadow: 0 0 0 4px var(--c-yuzu-soft);
}
.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -1px;
  color: var(--c-navy);
}
.hero h1 .hl {
  background: linear-gradient(120deg, var(--c-blue), var(--c-yuzu-deep));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p.lead {
  margin-top: 22px;
  font-size: 18px;
  color: var(--c-text-soft);
  max-width: 540px;
}
.hero-actions { margin-top: 34px; display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats {
  margin-top: 40px;
  display: flex;
  gap: 38px;
  flex-wrap: wrap;
}
.hero-stats .stat .num {
  font-size: 30px; font-weight: 800; color: var(--c-navy);
}
.hero-stats .stat .num span { color: var(--c-blue); }
.hero-stats .stat .label { font-size: 13px; color: var(--c-text-soft); }

/* Hero 右侧：产品视觉卡 */
.hero-visual { position: relative; }
.phone-card {
  position: relative;
  margin: 0 auto;
  width: 300px;
  max-width: 100%;
  height: 600px;
  border-radius: 38px;
  background: linear-gradient(160deg, var(--c-navy), var(--c-navy-2));
  box-shadow: var(--shadow);
  padding: 16px;
  border: 6px solid #0b1f3a;
}
.phone-screen {
  height: 100%;
  border-radius: 26px;
  background: linear-gradient(180deg, #f4f8ff, #eaf2ff);
  overflow: hidden;
  position: relative;
  display: flex;
  flex-direction: column;
}
.phone-top {
  padding: 26px 22px 18px;
  background: linear-gradient(135deg, var(--c-blue), var(--c-yuzu-deep));
  color: #fff;
}
.phone-top .pt-title { font-size: 14px; opacity: .9; }
.phone-top .pt-name { font-size: 22px; font-weight: 800; margin-top: 4px; }
.phone-body { padding: 20px 22px; flex: 1; }
.unlock-btn {
  margin-top: 10px;
  height: 150px;
  border-radius: 20px;
  background: linear-gradient(135deg, var(--c-yuzu), var(--c-yuzu-deep));
  display: grid;
  place-items: center;
  color: #fff;
  text-align: center;
  box-shadow: 0 16px 30px -14px rgba(63, 168, 90, .8);
  animation: pulse 2.4s infinite;
}
.unlock-btn .ico { font-size: 40px; }
.unlock-btn .txt { font-weight: 700; font-size: 17px; margin-top: 6px; }
.unlock-btn .sub { font-size: 12px; opacity: .85; }
@keyframes pulse {
  0%, 100% { box-shadow: 0 16px 30px -14px rgba(63,168,90,.7); }
  50% { box-shadow: 0 16px 40px -8px rgba(63,168,90,1); }
}
.phone-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 16px; }
.phone-mini {
  background: #fff; border-radius: 14px; padding: 14px;
  box-shadow: var(--shadow-sm);
}
.phone-mini .m-ico { font-size: 20px; }
.phone-mini .m-t { font-size: 13px; font-weight: 700; color: var(--c-navy); margin-top: 6px; }
.phone-mini .m-d { font-size: 11px; color: var(--c-text-soft); }

/* ===================== 优势卡片 ===================== */
.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}
.feature {
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: 34px 30px;
  transition: transform .25s, box-shadow .25s, border-color .25s;
}
.feature:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: transparent; }
.feature .f-ico {
  width: 56px; height: 56px;
  border-radius: 15px;
  background: var(--c-blue-soft);
  display: grid; place-items: center;
  font-size: 26px;
  margin-bottom: 20px;
}
.feature h3 { font-size: 19px; font-weight: 700; color: var(--c-navy); }
.feature p { margin-top: 10px; color: var(--c-text-soft); font-size: 15px; }

/* ===================== 场景 ===================== */
.scenes {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 26px;
}
.scene {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  min-height: 280px;
  padding: 40px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  color: #fff;
  border: 1px solid var(--c-line);
}
.scene.community {
  background: linear-gradient(135deg, rgba(11,31,58,.92), rgba(27,110,243,.78)),
              repeating-linear-gradient(45deg, rgba(255,255,255,.04) 0 12px, transparent 12px 24px);
}
.scene.campus {
  background: linear-gradient(135deg, rgba(11,31,58,.92), rgba(63,168,90,.78)),
              repeating-linear-gradient(45deg, rgba(255,255,255,.04) 0 12px, transparent 12px 24px);
}
.scene .s-ico { font-size: 40px; margin-bottom: 14px; }
.scene h3 { font-size: 24px; font-weight: 800; }
.scene p { margin-top: 8px; opacity: .9; font-size: 15px; max-width: 420px; }
.scene ul.scene-list {
  margin-top: 16px; display: flex; flex-wrap: wrap; gap: 8px;
}
.scene ul.scene-list li {
  font-size: 13px; padding: 5px 12px; border-radius: 999px;
  background: rgba(255,255,255,.16); backdrop-filter: blur(4px);
}

/* ===================== 数据条 ===================== */
.stats-band {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}
.stats-band .b-num {
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 800;
  color: var(--c-yuzu);
  letter-spacing: -1px;
}
.stats-band .b-label { margin-top: 8px; color: rgba(255,255,255,.8); font-size: 15px; }

/* ===================== 步骤 ===================== */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.step { text-align: center; position: relative; }
.step .s-no {
  width: 56px; height: 56px; margin: 0 auto 18px;
  border-radius: 50%;
  background: var(--c-blue-soft); color: var(--c-blue);
  display: grid; place-items: center; font-size: 22px; font-weight: 800;
  border: 2px solid #fff; box-shadow: var(--shadow-sm);
}
.step h4 { font-size: 17px; color: var(--c-navy); font-weight: 700; }
.step p { margin-top: 8px; color: var(--c-text-soft); font-size: 14px; }

/* ===================== 关于我们 ===================== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}
.about-text h2 { font-size: clamp(26px,4vw,36px); font-weight: 800; color: var(--c-navy); letter-spacing: -.5px; }
.about-text p { margin-top: 18px; color: var(--c-text-soft); font-size: 16px; }
.about-values { margin-top: 28px; display: grid; gap: 16px; }
.about-values .v-item { display: flex; gap: 14px; align-items: flex-start; }
.about-values .v-ico {
  flex: 0 0 auto; width: 40px; height: 40px; border-radius: 11px;
  background: var(--c-yuzu-soft); display: grid; place-items: center; font-size: 19px;
}
.about-values .v-text h4 { font-size: 16px; color: var(--c-navy); }
.about-values .v-text p { margin-top: 2px; font-size: 14px; }

.about-visual {
  border-radius: var(--radius);
  min-height: 420px;
  background:
    radial-gradient(600px 300px at 80% 10%, rgba(101,196,102,.25), transparent 60%),
    linear-gradient(160deg, var(--c-navy), var(--c-navy-2));
  position: relative;
  overflow: hidden;
  display: flex; align-items: center; justify-content: center;
}
.about-visual .av-badge {
  text-align: center; color: #fff;
}
.about-visual .av-badge .big { font-size: 64px; font-weight: 800; letter-spacing: -2px; }
.about-visual .av-badge .small { color: rgba(255,255,255,.75); margin-top: 6px; letter-spacing: 4px; }
.about-visual .float-tag {
  position: absolute; padding: 10px 16px; border-radius: 12px;
  background: rgba(255,255,255,.12); backdrop-filter: blur(8px);
  color: #fff; font-size: 13px; font-weight: 600; border: 1px solid rgba(255,255,255,.2);
}
.about-visual .ft-1 { top: 36px; left: 30px; }
.about-visual .ft-2 { bottom: 40px; right: 30px; }

/* 时间线 */
.timeline { max-width: 780px; margin: 0 auto; position: relative; }
.timeline::before {
  content: ""; position: absolute; left: 22px; top: 6px; bottom: 6px;
  width: 2px; background: var(--c-line);
}
.tl-item { position: relative; padding: 0 0 34px 64px; }
.tl-item .tl-dot {
  position: absolute; left: 13px; top: 4px;
  width: 20px; height: 20px; border-radius: 50%;
  background: var(--c-blue); border: 4px solid var(--c-blue-soft);
}
.tl-item .tl-year { font-weight: 800; color: var(--c-navy); font-size: 16px; }
.tl-item .tl-title { font-weight: 700; color: var(--c-navy); margin-top: 2px; }
.tl-item p { color: var(--c-text-soft); font-size: 14px; margin-top: 4px; }

/* ===================== 产品服务 ===================== */
.product-hero {
  display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center;
  background: linear-gradient(160deg, var(--c-navy), var(--c-navy-2));
  border-radius: 24px; padding: 56px; color: #fff; overflow: hidden; position: relative;
}
.product-hero::after {
  content: ""; position: absolute; right: -80px; top: -80px;
  width: 320px; height: 320px; border-radius: 50%;
  background: radial-gradient(circle, rgba(101,196,102,.4), transparent 70%);
}
.product-hero .ph-tag {
  display: inline-block; font-size: 13px; font-weight: 700; letter-spacing: 2px;
  color: var(--c-yuzu); margin-bottom: 14px;
}
.product-hero h2 { font-size: clamp(26px,4vw,38px); font-weight: 800; }
.product-hero p { margin-top: 16px; color: rgba(255,255,255,.82); font-size: 16px; }
.product-hero .ph-feats { margin-top: 24px; display: flex; flex-wrap: wrap; gap: 10px; }
.product-hero .ph-feats span {
  font-size: 13px; padding: 7px 14px; border-radius: 999px;
  background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.2);
}
.product-phone {
  position: relative; justify-self: center;
  width: 250px; max-width: 100%; height: 500px; border-radius: 34px; padding: 14px;
  background: #0b1f3a; border: 5px solid #0b1f3a; box-shadow: var(--shadow);
}
.product-phone .ps {
  height: 100%; border-radius: 22px; overflow: hidden;
  background: linear-gradient(180deg,#f4f8ff,#eaf2ff); display:flex; flex-direction:column;
}
.product-phone .ps-top { padding: 22px; background: linear-gradient(135deg,var(--c-blue),var(--c-yuzu-deep)); color:#fff; }
.product-phone .ps-top .t1 { font-size: 12px; opacity:.9; }
.product-phone .ps-top .t2 { font-size: 19px; font-weight: 800; margin-top: 3px; }
.product-phone .ps-body { padding: 18px; flex:1; }
.product-phone .ps-unlock {
  height: 120px; border-radius: 18px; margin-top: 4px;
  background: linear-gradient(135deg,var(--c-yuzu),var(--c-yuzu-deep));
  display:grid; place-items:center; color:#fff; text-align:center;
}
.product-phone .ps-unlock .i { font-size: 34px; }
.product-phone .ps-unlock .x { font-weight:700; margin-top:4px; }

.func-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; }
.func {
  background:#fff; border:1px solid var(--c-line); border-radius: var(--radius);
  padding: 30px 26px; transition: transform .25s, box-shadow .25s, border-color .25s;
}
.func:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: transparent; }
.func .fc-ico {
  width: 52px; height: 52px; border-radius: 14px; background: var(--c-yuzu-soft);
  display:grid; place-items:center; font-size: 24px; margin-bottom: 16px;
}
.func h4 { font-size: 17px; color: var(--c-navy); font-weight: 700; }
.func p { margin-top: 8px; color: var(--c-text-soft); font-size: 14px; }

.svc-list { display: grid; grid-template-columns: repeat(3,1fr); gap: 24px; }
.svc {
  padding: 30px 26px; border-radius: var(--radius);
  border: 1px solid var(--c-line); background:#fff;
}
.svc .sv-no { font-size: 14px; font-weight: 800; color: var(--c-blue); }
.svc h4 { margin-top: 8px; font-size: 17px; color: var(--c-navy); font-weight: 700; }
.svc p { margin-top: 8px; color: var(--c-text-soft); font-size: 14px; }

/* ===================== 联系我们 ===================== */
.contact-grid {
  display: grid; grid-template-columns: 1fr 1.1fr; gap: 56px; align-items: start;
}
.contact-info .ci-item { display: flex; gap: 16px; margin-bottom: 26px; }
.contact-info .ci-ico {
  flex: 0 0 auto; width: 48px; height: 48px; border-radius: 13px;
  background: var(--c-blue-soft); display: grid; place-items: center; font-size: 22px;
}
.contact-info .ci-text h4 { font-size: 15px; color: var(--c-text-soft); font-weight: 600; }
.contact-info .ci-text p { font-size: 16px; color: var(--c-navy); font-weight: 700; margin-top: 2px; }

.form-card {
  background: #fff; border: 1px solid var(--c-line);
  border-radius: var(--radius); padding: 38px; box-shadow: var(--shadow-sm);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 14px; font-weight: 600; color: var(--c-navy); margin-bottom: 8px; }
.field label .req { color: #e4572e; }
.field input, .field textarea {
  width: 100%; padding: 13px 15px; font-size: 15px;
  border: 1px solid var(--c-line); border-radius: var(--radius-sm);
  font-family: inherit; color: var(--c-text); background: #fbfcfe;
  transition: border-color .2s, box-shadow .2s;
}
.field input:focus, .field textarea:focus {
  outline: none; border-color: var(--c-blue);
  box-shadow: 0 0 0 4px var(--c-blue-soft); background:#fff;
}
.field textarea { resize: vertical; min-height: 120px; }
.field .err { color: #e4572e; font-size: 13px; margin-top: 6px; display: none; }
.field.invalid input, .field.invalid textarea { border-color: #e4572e; }
.field.invalid .err { display: block; }
.form-note { font-size: 13px; color: var(--c-text-soft); margin-top: 4px; }
.form-success {
  display: none; margin-bottom: 18px; padding: 14px 16px; border-radius: var(--radius-sm);
  background: var(--c-yuzu-soft); color: var(--c-yuzu-deep); font-size: 14px; font-weight: 600;
}
.form-success.show { display: block; }

.map-placeholder {
  margin-top: 30px; border-radius: var(--radius); overflow: hidden;
  height: 280px; border: 1px solid var(--c-line);
  background:
    linear-gradient(135deg, rgba(27,110,243,.08), rgba(101,196,102,.08)),
    repeating-linear-gradient(0deg, var(--c-line) 0 1px, transparent 1px 28px),
    repeating-linear-gradient(90deg, var(--c-line) 0 1px, transparent 1px 28px);
  position: relative; display: grid; place-items: center;
}
.map-placeholder .mp-pin {
  text-align: center; color: var(--c-navy);
}
.map-placeholder .mp-pin .pin { font-size: 36px; }
.map-placeholder .mp-pin p { font-size: 14px; font-weight: 600; margin-top: 4px; }

/* ===================== 页脚 ===================== */
.footer {
  background: var(--c-bg-dark);
  color: rgba(255,255,255,.72);
  padding: 64px 0 28px;
}
.footer-grid {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px;
}
.footer .f-brand .brand { color: #fff; margin-bottom: 16px; }
.footer .f-brand .brand .brand-name { color: #fff; }
.footer .f-brand p { font-size: 14px; max-width: 280px; }
.footer h5 { color: #fff; font-size: 15px; margin-bottom: 16px; font-weight: 700; }
.footer ul li { margin-bottom: 11px; font-size: 14px; }
.footer ul li a:hover { color: var(--c-yuzu); }
.footer-bottom {
  margin-top: 48px; padding-top: 24px; border-top: 1px solid rgba(255,255,255,.1);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  font-size: 13px; color: rgba(255,255,255,.5);
}
.footer-bottom .links { display: flex; gap: 20px; }

/* ===================== 进入动画 ===================== */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ===================== 响应式 ===================== */
@media (max-width: 980px) {
  .hero-grid, .about-grid, .product-hero, .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  .features, .func-grid, .svc-list { grid-template-columns: repeat(2, 1fr); }
  .stats-band, .steps { grid-template-columns: repeat(2, 1fr); gap: 30px 16px; }
  .scenes { grid-template-columns: 1fr; }
  .product-phone, .hero-visual { justify-self: center; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
  .product-hero { padding: 40px; }
}

@media (max-width: 680px) {
  section { padding: 64px 0; }
  .nav-links {
    position: fixed; top: 68px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 4px;
    background: #fff; padding: 16px 20px 24px; border-bottom: 1px solid var(--c-line);
    box-shadow: var(--shadow); transform: translateY(-12px); opacity: 0; pointer-events: none;
    transition: .3s;
  }
  .nav-links.open { transform: none; opacity: 1; pointer-events: auto; }
  .nav-links a { padding: 12px 14px; }
  .nav-cta { margin: 6px 0 0; text-align: center; }
  .nav-toggle { display: flex; }
  .features, .func-grid, .svc-list, .stats-band, .steps, .footer-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .hero-stats { gap: 24px; }
  .container { padding: 0 18px; }
  .about-visual { min-height: 320px; }
}

/* 折叠菜单动画 */
.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }