/* ===== 捷飞高电路官网全局样式（零 JS，纯 HTML+CSS，SEO/性能优先） ===== */
:root {
  --primary: #e8590c;
  --primary-dark: #c9480a;
  --dark: #16232e;
  --text: #2c3e50;
  --muted: #6b7c8c;
  --line: #e6ebf0;
  --bg-soft: #f7f9fb;
  --maxw: 1200px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { padding-left: 20px; }

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

/* ===== 头部 ===== */
.hd {
  background: rgba(255, 255, 255, .96);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 100;
}
.hd .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 68px;
}
.hd .logo img { height: 34px; }
.nav a {
  margin-left: 30px; font-size: 15px; color: var(--text);
  position: relative; padding: 4px 0;
}
.nav a::after {
  content: ''; position: absolute; left: 0; bottom: 0;
  width: 0; height: 2px; background: var(--primary);
  transition: width .22s;
}
.nav a:hover { color: var(--primary); }
.nav a:hover::after { width: 100%; }
.nav a.on { color: var(--primary); font-weight: 600; }
.nav a.on::after { width: 100%; }

.nav-toggle { display: none; font-size: 24px; cursor: pointer; background: none; border: 0; }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 12px 28px; border-radius: 3px; font-size: 15px; font-weight: 500;
  transition: all .2s; border: 1px solid transparent; cursor: pointer;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-ghost { border-color: var(--primary); color: var(--primary); }
.btn-ghost:hover { background: var(--primary); color: #fff; }
.btn-lg { padding: 15px 38px; font-size: 16px; }

/* ===== 区块标题 ===== */
.sec { padding: 76px 0; }
.sec-alt { background: var(--bg-soft); }
.sec-head { text-align: center; margin-bottom: 46px; }
.sec-head .eyebrow {
  display: inline-block; font-size: 13px; letter-spacing: 2px;
  color: var(--primary); font-weight: 600; margin-bottom: 10px;
}
.sec-head h2 { font-size: 32px; margin: 0 0 12px; color: var(--dark); line-height: 1.35; }
.sec-head p { color: var(--muted); margin: 0; font-size: 15px; }

/* ===== Hero ===== */
.hero {
  position: relative; min-height: 560px;
  display: flex; align-items: center;
  background: #0e1a24;
  overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; }
.hero-bg img { width: 100%; height: 100%; object-fit: cover; opacity: .5; }
.hero-mask {
  position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(10, 22, 32, .94) 0%, rgba(10, 22, 32, .82) 45%, rgba(10, 22, 32, .55) 100%);
}
.hero .wrap { position: relative; z-index: 2; color: #fff; padding: 70px 24px; }
.hero h1 {
  font-size: 44px; line-height: 1.3; margin: 0 0 8px;
  font-weight: 700; letter-spacing: 1px;
}
.hero .en {
  font-size: 14px; letter-spacing: 3px; color: #7fb3d5;
  text-transform: uppercase; margin-bottom: 22px;
}
.hero .sub { font-size: 17px; color: #c6d6e0; max-width: 620px; margin: 0 0 32px; }
.hero .acts { display: flex; gap: 14px; flex-wrap: wrap; }
.hero .btn-ghost { border-color: #fff; color: #fff; }
.hero .btn-ghost:hover { background: #fff; color: var(--dark); }

/* ===== 业务卡片 ===== */
.biz-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 26px;
}
.biz-card {
  background: #fff; border: 1px solid var(--line); padding: 34px 28px;
  transition: all .25s; position: relative; overflow: hidden;
}
.biz-card::before {
  content: ''; position: absolute; left: 0; top: 0; height: 3px; width: 0;
  background: var(--primary); transition: width .3s;
}
.biz-card:hover { transform: translateY(-4px); box-shadow: 0 14px 34px rgba(0, 0, 0, .08); }
.biz-card:hover::before { width: 100%; }
.biz-no { font-size: 13px; color: var(--primary); font-weight: 700; letter-spacing: 1px; }
.biz-card h3 { font-size: 20px; margin: 10px 0 12px; color: var(--dark); }
.biz-card p { color: var(--muted); font-size: 14px; margin: 0 0 16px; }
.biz-list { list-style: none; padding: 0; margin: 0; font-size: 14px; color: #4a5b6b; }
.biz-list li { padding: 5px 0 5px 16px; position: relative; }
.biz-list li::before {
  content: ''; position: absolute; left: 0; top: 14px;
  width: 5px; height: 5px; background: var(--primary); border-radius: 50%;
}

/* ===== 数据条 ===== */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 20px; }
.stat { text-align: center; padding: 26px 12px; background: var(--dark); }
.stat .n { font-size: 40px; color: var(--primary); font-weight: 700; line-height: 1.1; }
.stat .n small { font-size: 18px; }
.stat .t { color: #9fb0bd; font-size: 14px; margin-top: 6px; }

/* ===== 特性/优势 ===== */
.feat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 26px; }
.feat { text-align: center; padding: 8px; }
.feat .ico {
  width: 62px; height: 62px; margin: 0 auto 16px;
  background: rgba(232, 89, 12, .09);
  display: flex; align-items: center; justify-content: center;
  font-size: 27px; border-radius: 50%;
}
.feat h3 { font-size: 17px; margin: 0 0 8px; color: var(--dark); }
.feat p { font-size: 14px; color: var(--muted); margin: 0; }

/* ===== 图片组 ===== */
.img-split { display: grid; grid-template-columns: 1.15fr 1fr; gap: 36px; align-items: center; }
.img-split.rev { grid-template-columns: 1fr 1.15fr; }
.img-split.rev .txt-col { order: 2; }
.img-split img { border-radius: 4px; width: 100%; }
.img-split h3 { font-size: 25px; color: var(--dark); margin: 0 0 14px; }
.img-split p { color: var(--muted); font-size: 15px; }

/* ===== 工艺流程 ===== */
.flow { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 0; }
.flow-step {
  position: relative; padding: 26px 14px; text-align: center;
  background: #fff; border: 1px solid var(--line); margin-right: -1px; margin-bottom: -1px;
}
.flow-step .n {
  width: 34px; height: 34px; margin: 0 auto 12px; border-radius: 50%;
  background: var(--primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 14px;
}
.flow-step h4 { margin: 0 0 6px; font-size: 15px; color: var(--dark); }
.flow-step p { margin: 0; font-size: 12.5px; color: var(--muted); }

/* ===== 表格 ===== */
.tbl { width: 100%; border-collapse: collapse; font-size: 14px; background: #fff; }
.tbl th, .tbl td { border: 1px solid var(--line); padding: 12px 14px; text-align: left; }
.tbl th { background: var(--bg-soft); color: var(--dark); font-weight: 600; white-space: nowrap; }
.tbl td.num { text-align: right; font-variant-numeric: tabular-nums; }

/* ===== 新闻列表 ===== */
.news-list { display: grid; gap: 20px; }
.news-item {
  display: flex; gap: 22px; align-items: center;
  background: #fff; border: 1px solid var(--line); padding: 20px 24px; transition: all .2s;
}
.news-item:hover { border-color: var(--primary); transform: translateX(4px); }
.news-item img { width: 168px; height: 112px; object-fit: cover; border-radius: 3px; flex-shrink: 0; }
.news-item .ni-txt { flex: 1; min-width: 0; }
.news-item h3 { margin: 0 0 6px; font-size: 17px; color: var(--dark); }
.news-item p { margin: 0 0 8px; color: var(--muted); font-size: 14px;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.news-item time { color: #9aa7b2; font-size: 13px; }
.tag {
  display: inline-block; background: rgba(232, 89, 12, .1); color: var(--primary);
  font-size: 12px; padding: 2px 9px; border-radius: 2px; margin-right: 8px;
}

/* ===== CTA ===== */
.cta {
  background: linear-gradient(105deg, var(--primary) 0%, #f2762c 100%);
  color: #fff; text-align: center; padding: 66px 24px;
}
.cta h2 { font-size: 28px; margin: 0 0 10px; }
.cta p { opacity: .9; margin: 0 0 26px; }
.cta .btn { background: #fff; color: var(--primary); }
.cta .btn:hover { background: var(--dark); color: #fff; }

/* ===== 页脚 ===== */
.ft { background: var(--dark); color: #c6d2dc; padding: 52px 0 0; font-size: 14px; }
.ft .wrap { display: flex; flex-wrap: wrap; gap: 46px; padding-bottom: 34px; }
.ft-col { min-width: 190px; }
.ft-col b { display: block; color: #fff; margin-bottom: 12px; font-size: 15px; }
.ft-col p, .ft-col a { display: block; color: #8fa1af; font-size: 13.5px; margin: 5px 0; }
.ft-col a:hover { color: #fff; }
.copy {
  border-top: 1px solid rgba(255, 255, 255, .08);
  padding: 16px 24px; text-align: center; font-size: 12.5px; color: #6f7f8c;
}

/* ===== 内页 Hero ===== */
.page-hero {
  background: var(--dark); color: #fff; padding: 62px 24px; text-align: center;
}
.page-hero h1 { font-size: 32px; margin: 0 0 10px; color: #fff; }
.page-hero p { margin: 0; color: #9fb0bd; }

/* ============================================================
   响应式 / H5 优化（≤900px）
   设计基调：小清新浅色 + 细腻紧凑
   - 头部固定 44px（含安全区），Logo 缩到 26px 高
   - 正文字号整体下调 1~3px，行高收紧，区块留白减半
   - 主色在 H5 换成低饱和青绿（#2f9e8f），视觉更柔和
   ============================================================ */
@media (max-width: 900px) {
  /* ---- H5 局部变量：小清新配色 + 更紧的留白 ---- */
  :root {
    /* 主色取自 logo 原色 #00AE4F 的低饱和版本，与顶部 logo 完全同色系 */
    --primary: #17a97f;
    --primary-dark: #128a68;
    --text: #3d4a52;            /* 不用纯黑，降低对比刺激 */
    --muted: #8496a1;
    --line: #eef2f4;            /* 更浅的分隔线 */
    --bg-soft: #f7faf9;         /* 浅青白替代原来的冷灰白 */
  }
  body {
    line-height: 1.7;
    font-size: 14px;
    -webkit-text-size-adjust: 100%;  /* 防止 iOS 横屏字号被放大 */
  }
  /* 左右边距收到 8px，让内容更贴近屏幕、显得更大气 */
  .wrap { padding: 0 8px; }

  /* ---- 头部：44px 紧凑条 ---- */
  .hd {
    background: rgba(255, 255, 255, .92);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid rgba(238, 242, 244, .9);
  }
  .hd .wrap {
    height: 44px;                 /* 核心：44px 标准高度 */
    padding-top: env(safe-area-inset-top);
    padding-left: max(8px, env(safe-area-inset-left));
    padding-right: max(8px, env(safe-area-inset-right));
  }
  .hd .logo img { height: 22px; }  /* logo 再小一档，44px 条内更透气 */

  /* 汉堡按钮：细线条，避免 ☰ 字形在小屏上发糊 */
  .nav-toggle {
    display: flex; align-items: center; justify-content: center;
    width: 40px; height: 40px; margin-right: -8px;   /* 扩大点按热区（≥40px 符合触控标准） */
    font-size: 0; cursor: pointer;
    background: none; border: 0; padding: 0;
    position: relative;
  }
  .nav-toggle::before,
  .nav-toggle::after,
  .nav-toggle span {
    content: ''; position: absolute; left: 10px; right: 10px; height: 1.5px;
    background: var(--text); border-radius: 2px;
    transition: transform .25s, opacity .2s;
  }
  .nav-toggle::before { top: 15px; }
  .nav-toggle span { top: 19.5px; }
  .nav-toggle::after { top: 24px; }
  .nav-toggle[aria-expanded="true"]::before { transform: translateY(4.5px) rotate(45deg); }
  .nav-toggle[aria-expanded="true"] span { opacity: 0; }
  .nav-toggle[aria-expanded="true"]::after { transform: translateY(-4.5px) rotate(-45deg); }

  /* 下拉菜单：紧贴 44px 头部下方 */
  .nav {
    display: none;
    position: absolute; top: 44px; left: 0; right: 0;
    background: rgba(255, 255, 255, .98);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--line);
    padding: 4px 12px 12px;
    flex-direction: column;
    box-shadow: 0 6px 18px rgba(61, 74, 82, .07);
    max-height: calc(100vh - 44px); overflow-y: auto;
  }
  .nav.show { display: flex; }
  .nav a {
    margin: 0; padding: 11px 2px; font-size: 14px;   /* 触控高度 ~42px */
    border-bottom: 1px solid rgba(238, 242, 244, .6);
  }
  .nav a:last-child { border-bottom: 0; }
  .nav a::after { display: none; }                    /* 小屏去掉下划线动画，改用文字变色 */
  .nav a.on { color: var(--primary); }

  /* ---- Hero：压缩高度，字号收敛 ---- */
  .hero { min-height: 340px; }
  .hero-bg img { opacity: .38; }                      /* 浅一点，小清新 */
  .hero-mask {
    background: linear-gradient(160deg, rgba(247, 250, 249, .96) 0%, rgba(240, 247, 245, .9) 55%, rgba(233, 243, 240, .85) 100%);
  }
  .hero .wrap { padding: 44px 8px 48px; }
  .hero .en { font-size: 11px; letter-spacing: 2px; margin-bottom: 12px; color: #6fa89d; }
  .hero h1 {
    font-size: 25px; line-height: 1.42; letter-spacing: .5px;
    color: var(--text); font-weight: 600; margin-bottom: 10px;
  }
  .hero .sub {
    font-size: 13.5px; color: #6b7d85; max-width: none;
    margin-bottom: 22px; line-height: 1.75;
  }
  .hero .acts { gap: 10px; }
  .hero .btn { padding: 9px 18px; font-size: 13px; border-radius: 2px; }
  .hero .btn-ghost { border-color: var(--primary); color: var(--primary); }
  .hero .btn-ghost:hover { background: var(--primary); color: #fff; }

  /* ---- 区块：留白减半 ---- */
  .sec { padding: 34px 0; }
  .sec-alt { background: var(--bg-soft); }
  .sec-head { margin-bottom: 24px; }
  .sec-head .eyebrow { font-size: 11px; letter-spacing: 1.5px; margin-bottom: 6px; }
  .sec-head h2 { font-size: 19px; margin: 0 0 8px; font-weight: 600; }
  .sec-head p { font-size: 13px; }

  /* ---- 业务卡片：去掉重边框，改淡阴影，更细腻 ---- */
  .biz-grid { gap: 12px; grid-template-columns: 1fr; }
  .biz-card {
    padding: 18px 16px;
    border: 0; border-radius: 4px;
    background: #fff;
    box-shadow: 0 1px 3px rgba(61, 74, 82, .05);
  }
  .biz-card::before { height: 2px; }
  .biz-card:hover { transform: none; box-shadow: 0 3px 10px rgba(61, 74, 82, .08); }
  .biz-no { font-size: 11px; letter-spacing: 1px; }
  .biz-card h3 { font-size: 15px; margin: 6px 0 8px; font-weight: 600; }
  .biz-card p, .biz-list li { font-size: 13px; }
  .biz-list { padding-left: 16px; }

  /* ---- 图片分栏：改为上下堆叠 ---- */
  .img-split, .img-split.rev { grid-template-columns: 1fr; gap: 16px; }
  .img-split.rev .txt-col { order: 0; }
  .img-split img { height: 168px; object-fit: cover; border-radius: 4px; }
  .txt-col h3 { font-size: 17px; }
  .txt-col p { font-size: 13.5px; margin-bottom: 10px; }

  /* ---- 内页顶部：深色 banner → 浅色，融入小清新 ---- */
  .page-hero {
    background: linear-gradient(180deg, #f2f8f6 0%, #eaf4f1 100%);
    color: var(--text);
    padding: 30px 8px;
    border-bottom: 1px solid rgba(23, 169, 127, .1);
  }
  .page-hero h1 { font-size: 19px; margin-bottom: 5px; color: var(--text); font-weight: 600; }
  .page-hero p { font-size: 12.5px; color: var(--muted); }

  /* ---- 表格：横向滚动，不撑破屏幕 ---- */
  .tbl-wrap, .tbl { font-size: 13px; }
  .tbl th, .tbl td { padding: 9px 10px; }
  .tbl { display: block; overflow-x: auto; white-space: nowrap; -webkit-overflow-scrolling: touch; }

  /* ---- 新闻条目 ---- */
  .news-item { flex-direction: column; align-items: flex-start; gap: 12px; padding: 16px; }
  .news-item img { width: 100%; height: 140px; object-fit: cover; border-radius: 4px; }
  .news-item h3 { font-size: 15px; }

  /* ---- 特性网格 ---- */
  .feat-grid { gap: 12px; grid-template-columns: 1fr; }
  .feat {
    padding: 16px; border: 0; border-radius: 4px;
    background: #fff; box-shadow: 0 1px 3px rgba(61, 74, 82, .05);
  }
  .feat h3 { font-size: 14.5px; margin: 6px 0 6px; }
  .feat p { font-size: 13px; }
  .feat .ico {
    width: 30px; height: 30px; font-size: 15px;
    background: rgba(23, 169, 127, .1); color: var(--primary);
    border-radius: 50%;
  }

  /* ---- 流程步骤：去边框改淡阴影，圆角收小 ---- */
  .flow { gap: 10px; grid-template-columns: 1fr; }
  .flow-step {
    padding: 14px 16px;
    border: 0; border-radius: 4px;
    background: #fff; box-shadow: 0 1px 3px rgba(61, 74, 82, .05);
  }
  .flow-step .n {
    font-size: 15px; color: var(--primary);
    background: rgba(23, 169, 127, .1);
    width: 30px; height: 30px; line-height: 30px;
    display: inline-flex; align-items: center; justify-content: center;
    border-radius: 50%; margin-bottom: 8px;
  }
  .flow-step h4 { font-size: 14.5px; margin: 0 0 4px; font-weight: 600; }
  .flow-step p { font-size: 12.5px; line-height: 1.65; }

  /* ---- 数据条：深色 → 浅青，融入小清新 ---- */
  .stats { gap: 10px; }
  .stat {
    padding: 16px 10px;
    background: #fff;
    border-radius: 4px;
    box-shadow: 0 1px 3px rgba(61, 74, 82, .05);
  }
  .stat .n { font-size: 26px; color: var(--primary); }
  .stat .n small { font-size: 13px; }
  .stat .t { color: var(--muted); font-size: 12px; margin-top: 2px; }

  /* ---- CTA：浅绿底 + 白卡片按钮，不用深色 ---- */
  .cta {
    padding: 32px 8px;
    background: linear-gradient(180deg, #f7faf9 0%, #eaf4f1 100%);
    color: var(--text);
  }
  .cta h2 { font-size: 19px; margin: 0 0 7px; color: var(--text); }
  .cta p { opacity: 1; color: var(--muted); font-size: 13px; margin: 0 0 16px; }
  .cta .btn { background: var(--primary); color: #fff; }
  .cta .btn:hover { background: var(--primary-dark); color: #fff; }
  .btn-lg { padding: 11px 26px; font-size: 14px; }

  /* ---- 页脚：深色 → 浅色，融入小清新 ---- */
  .ft {
    background: #f4f8f7;
    color: var(--muted);
    padding: 26px 0 0;
    font-size: 12.5px;
    border-top: 1px solid rgba(23, 169, 127, .12);
  }
  .ft .wrap { gap: 22px; padding-bottom: 20px; }
  .ft-col { min-width: 0; }
  .ft-col b { display: block; color: var(--text); margin-bottom: 7px; font-size: 13px; font-weight: 600; }
  .ft-col p, .ft-col a { display: block; color: var(--muted); font-size: 12.5px; margin: 4px 0; }
  .ft-col a:hover { color: var(--primary); }
  .ft .copy {
    border-top: 1px solid rgba(23, 169, 127, .12);
    padding: 14px 0; color: var(--muted); font-size: 12px;
  }

  /* ---- 表单控件加大点按热区 ---- */
  input, select, textarea { font-size: 16px !important; }  /* <16px 时 iOS 聚焦会自动放大 */
  input, select {
    padding: 10px !important; border-radius: 3px !important;
  }
  .biz-card form input, .biz-card form select, .biz-card form textarea { width: 100%; }

  /* ==========================================================
     滚动加载动画（原生 CSS scroll-driven，零 JS）
     原理：animation-timeline: view() 让动画时间轴绑定到元素进入视口的进度，
           往下滚 → 元素逐块淡入上移。
     兼容性：Chrome/Edge 115+、Safari 26+。老浏览器直接忽略 animation，
             元素保持默认可见状态（不会白屏），这是优雅降级。
     ========================================================== */
  @supports (animation-timeline: view()) {
    /* 区块内的主要内容作为动画主体 */
    .sec .wrap > *:not(.biz-grid):not(.feat-grid):not(.flow),
    .sec > .wrap > *:not(.biz-grid):not(.feat-grid):not(.flow),
    .stats .stat,
    .cta > .wrap > * {
      animation: riseIn linear both;
      animation-timeline: view();
      animation-range: cover 6% cover 20%;   /* 视口覆盖 6% 开始，20% 完成（更早播完，避免首屏半透明） */
    }

    /* 同区块内的子元素错峰延迟，形成"一块块依次浮现"的层次 */
    .sec .wrap > *:nth-child(2):not(.biz-grid):not(.feat-grid):not(.flow) { animation-range: cover 9% cover 23%; }
    .sec .wrap > *:nth-child(3):not(.biz-grid):not(.feat-grid):not(.flow) { animation-range: cover 12% cover 26%; }
    .sec .wrap > *:nth-child(4):not(.biz-grid):not(.feat-grid):not(.flow) { animation-range: cover 15% cover 29%; }
    .stats .stat:nth-child(1) { animation-range: cover 6% cover 20%; }
    .stats .stat:nth-child(2) { animation-range: cover 9% cover 23%; }
    .stats .stat:nth-child(3) { animation-range: cover 12% cover 26%; }
    .stats .stat:nth-child(4) { animation-range: cover 15% cover 29%; }

    /* 卡片网格内的卡片逐个错峰（用 grid 子项序号） */
    .biz-grid > *, .feat-grid > *, .flow > * {
      animation: riseIn linear both;
      animation-timeline: view();
      animation-range: cover 7% cover 22%;
    }
    .biz-grid > *:nth-child(2), .feat-grid > *:nth-child(2), .flow > *:nth-child(2) { animation-range: cover 10% cover 25%; }
    .biz-grid > *:nth-child(3), .feat-grid > *:nth-child(3), .flow > *:nth-child(3) { animation-range: cover 13% cover 28%; }
    .biz-grid > *:nth-child(4), .feat-grid > *:nth-child(4), .flow > *:nth-child(4) { animation-range: cover 16% cover 31%; }

    @keyframes riseIn {
      from { opacity: 0; transform: translateY(16px); }
      to   { opacity: 1; transform: none; }
    }

    /* 兜底：首屏已在视口内的元素强制走更早区间，避免首屏发灰 */
    .hero ~ .sec .sec-head,
    .hero ~ .sec .wrap > :first-child:not(.biz-grid):not(.feat-grid):not(.flow),
    .sec-alt .stats .stat:nth-child(-n+2) {
      animation-range: cover 0% cover 12%;
    }

    /* 兜底：首屏已在视口内的元素强制走更早区间，避免首屏发灰 */
    .hero ~ .sec .sec-head,
    .hero ~ .sec .wrap > :first-child:not(.biz-grid):not(.feat-grid):not(.flow),
    .sec-alt .stats .stat:nth-child(-n+2) {
      animation-range: cover 0% cover 12%;
    }

    /* 减弱动画偏好：直接显示，不做位移 */
    @media (prefers-reduced-motion: reduce) {
      .sec .wrap > *, .sec > .wrap > *, .stats .stat, .cta > .wrap > *,
      .biz-grid > *, .feat-grid > *, .flow > * {
        animation: none; opacity: 1; transform: none;
      }
    }
  }

  /* ---- 层次感增强：卡片阴影分层 + 顶部细高光 ---- */
  .biz-card, .feat, .flow-step, .stat {
    box-shadow:
      0 1px 2px rgba(61, 74, 82, .04),   /* 近层：贴地的接触阴影 */
      0 4px 12px rgba(61, 74, 82, .04);  /* 远层：扩散的环境影 */
    transition: transform .28s cubic-bezier(.4, 0, .2, 1), box-shadow .28s;
  }
  .biz-card:active, .flow-step:active {
    transform: scale(.985);              /* 按下时轻微收缩，给触感反馈 */
  }
  /* 区块交替底色做出分界，替代原来靠边框 */
  .sec-alt { background: #f7faf9; }
  /* 区块标题下加一条短装饰线，强化层次锚点 */
  .sec-head h2::after {
    content: ''; display: block;
    width: 28px; height: 2px; margin: 10px auto 0;
    background: var(--primary); opacity: .55; border-radius: 1px;
  }
  /* 正文行高与字色再柔化一档 */
  .txt-col p, .biz-card p, .feat p { color: #6d7d86; letter-spacing: .1px; }
}

/* 超窄屏（iPhone SE 等 375px 以下）再收一档 */
@media (max-width: 380px) {
  .hd .logo img { height: 20px; }
  .hero h1 { font-size: 22px; }
  .sec-head h2 { font-size: 18px; }
  .wrap { padding: 0 8px; }
  .hero .wrap { padding: 36px 8px 40px; }
}