/* ============================================================
   天津特能物联平台 - 门户站样式
   结构：设计变量 → 基础排版 → 导航 → 首屏 → 通用区块
        → 平台预览 → 接入拓扑 → 产品矩阵 → 场景 → 企业简介
        → CTA → 页脚 → 下载页 → 响应式
   ============================================================ */

/* ---------------- 设计变量 ---------------- */
:root {
  --brand: #1d6fe8;
  --brand-deep: #0b52c4;
  --brand-2: #22b0ff;
  --ink: #0a1526;
  --ink-2: #33415c;
  --muted: #64748b;
  --line: #e5ecf6;
  --line-soft: #eef3fa;
  --soft: #f5f8fd;
  --dark: #061324;
  --dark-2: #0b2b57;
  --radius: 18px;
  --radius-sm: 12px;
  --shadow-sm: 0 6px 18px rgba(12, 38, 80, .06);
  --shadow: 0 18px 40px rgba(12, 38, 80, .10);
  --shadow-lg: 0 32px 70px rgba(7, 26, 58, .22);
  --wrap: 1200px;
}

/* ---------------- 基础排版 ---------------- */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: #fff;
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
/* height:auto 必须显式声明：HTML 的 height 属性会映射为 CSS 高度提示，
   只写 width:100% 会让图片按属性高度被拉伸 */
img { max-width: 100%; height: auto; display: block; border: 0; }
h1, h2, h3, h4 { line-height: 1.3; font-weight: 700; letter-spacing: .01em; }
p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
::selection { background: rgba(29, 111, 232, .16); }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 26px; }
.num { font-variant-numeric: tabular-nums; }

/* 可访问性：键盘焦点 */
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--brand-2);
  outline-offset: 3px;
  border-radius: 8px;
}

/* ---------------- 顶部导航 ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(255, 255, 255, .86);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line-soft);
}
.site-nav { display: flex; align-items: center; gap: 26px; height: 72px; }
/* 品牌区：徽标 + “天津特能 / 分隔线 / 物联平台” 组合（与参考图一致） */
.brand { display: flex; align-items: center; gap: 15px; flex: none; }
/* 【特能】徽标：纯 CSS 绘制（蓝渐变圆角方块 + 白字），不依赖图片 */
.brand-badge {
  --badge-size: 46px;          /* 徽标高度 */
  flex: none;
  height: calc(var(--badge-size) * .974);
  border-radius: calc(var(--badge-size) * .168);
  /* 宽度随文字自适应：4 个汉字排在一行，最短与高度等宽（近似正方形） */
  min-width: calc(var(--badge-size) * 1.02);
  padding: 0 calc(var(--badge-size) * .19);
  font-size: calc(var(--badge-size) * .335);
  background: linear-gradient(180deg, #0aadeb 0%, #0180dc 52%, #0455cb 100%);
  color: #fff; font-weight: 700; letter-spacing: .02em; white-space: nowrap;
  display: inline-flex; align-items: center; justify-content: center; line-height: 1;
  box-shadow: 0 6px 14px rgba(10, 70, 150, .2);
}
.brand-lockup { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.brand-name {
  font-size: 19px; font-weight: 700; line-height: 1.1;
  color: var(--ink); letter-spacing: .26em; white-space: nowrap;
  margin-right: -.26em;   /* 抵消末字后的字距，保持与下方内容对齐 */
}
.brand-rule { height: 2px; border-radius: 2px; background: #005dc4; }
.brand-sub {
  display: flex; justify-content: space-between; gap: .1em;
  font-size: 10.5px; font-weight: 600; line-height: 1.15;
  color: #3b4a63; white-space: nowrap;
}
.brand-sub i { font-style: normal; }
.nav-links { display: flex; align-items: center; gap: 2px; margin-left: auto; }
.nav-links a {
  padding: 8px 14px; border-radius: 10px; color: var(--ink-2);
  font-size: .93rem; transition: color .16s, background .16s;
  flex: 0 0 auto; white-space: nowrap;
}
.nav-links a:hover { color: var(--brand); background: #f1f6ff; }
/* 用 .nav-links a.nav-cta 提高优先级，避免被 .nav-links a 的圆角/内边距覆盖 */
.nav-links a.nav-cta {
  margin-left: 12px; padding: 8px 20px;
  /* 白底蓝边描边按钮：与左上角的蓝色渐变徽标形成明显区分 */
  border-radius: 999px;
  background: #fff;
  border: 1.5px solid var(--brand);
  color: var(--brand) !important; font-weight: 600;
  box-shadow: none;
  transition: background .16s, color .16s, border-color .16s, box-shadow .16s;
}
/* 覆盖 .nav-links a:hover 的浅色背景，避免白字压在白底上看不清 */
.nav-links a.nav-cta:hover {
  background: var(--brand);
  color: #fff !important;
  border-color: var(--brand);
  box-shadow: 0 10px 22px rgba(29, 111, 232, .26);
}
.nav-toggle {
  display: none; margin-left: auto; width: 42px; height: 42px;
  border: 1px solid var(--line); border-radius: 12px; background: #fff;
  cursor: pointer; padding: 0; place-items: center; color: var(--ink);
}
.nav-toggle span { display: block; width: 18px; height: 2px; background: currentColor; border-radius: 2px; position: relative; }
.nav-toggle span::before, .nav-toggle span::after {
  content: ''; position: absolute; left: 0; width: 18px; height: 2px;
  background: currentColor; border-radius: 2px;
}
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }

/* ---------------- 首屏 ---------------- */
.hero {
  position: relative; overflow: hidden; color: #fff;
  /* 首屏：至少占满"视口高度 - 吸顶导航"，内容垂直居中，统计条也在一屏内 */
  display: flex; flex-direction: column; justify-content: center;
  min-height: calc(100vh - 73px);
  background:
    radial-gradient(900px 520px at 78% 8%, rgba(34, 176, 255, .30), transparent 62%),
    radial-gradient(700px 420px at 8% 92%, rgba(29, 111, 232, .34), transparent 66%),
    linear-gradient(150deg, #04101f 0%, #0a2750 52%, #0a3a7d 100%);
  padding: 64px 0 56px;
}
.hero > .wrap { width: 100%; }
.hero::before {
  content: ''; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, .045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .045) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(circle at 62% 30%, #000 12%, transparent 74%);
  -webkit-mask-image: radial-gradient(circle at 62% 30%, #000 12%, transparent 74%);
}
.hero-inner {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1.02fr 1.08fr;
  gap: 54px; align-items: center;
}
.hero-tag {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: 7px 16px; border-radius: 999px;
  background: rgba(34, 176, 255, .14); border: 1px solid rgba(34, 176, 255, .34);
  color: #86e5ff; font-size: .8rem; letter-spacing: .1em; font-weight: 600;
}
.hero h1 {
  margin: 20px 0 18px;
  font-size: clamp(1.76rem, 2.8vw, 2.42rem);
  line-height: 1.26; letter-spacing: .005em;
}
.hero h1 em { font-style: normal; color: #6fd8ff; }
.hero-h1-cyan { color: #6fd8ff; }   /* 第一行：青色 */
.hero-h1-green { color: #4ade80; }  /* 第二行：绿色 */
.hero-lead { color: #b6c9e4; font-size: 1.02rem; max-width: 560px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 32px; }
.btn-primary-lg, .btn-ghost-lg {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: 14px 28px; border-radius: 999px; font-size: .99rem; font-weight: 600;
  transition: transform .16s, box-shadow .16s, background .16s, border-color .16s;
}
.btn-primary-lg {
  background: linear-gradient(135deg, #2b86ff, #22c3ff); color: #fff;
  box-shadow: 0 14px 32px rgba(20, 130, 255, .42);
}
.btn-primary-lg:hover { transform: translateY(-2px); box-shadow: 0 18px 38px rgba(20, 130, 255, .5); }
.btn-ghost-lg { border: 1px solid rgba(255, 255, 255, .34); color: #fff; background: rgba(255, 255, 255, .04); }
.btn-ghost-lg:hover { background: rgba(255, 255, 255, .12); border-color: rgba(255, 255, 255, .5); }
.hero-points { display: flex; flex-wrap: wrap; gap: 10px 22px; margin-top: 28px; }
.hero-points li { display: flex; align-items: center; gap: .45rem; color: #cfe0f6; font-size: .89rem; }
.hero-points svg { flex: none; color: #45e0b0; }

/* 首屏产品截图（浏览器窗口拟物） */
.hero-visual { position: relative; }
.browser-frame {
  position: relative; border-radius: 16px; padding: 12px 12px 0;
  background: linear-gradient(180deg, #12233a, #0a1728);
  border: 1px solid rgba(255, 255, 255, .12);
  box-shadow: var(--shadow-lg);
}
.browser-frame::after {
  content: ''; position: absolute; inset: 0; border-radius: 16px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .16); pointer-events: none;
}
.browser-bar { display: flex; align-items: center; gap: 8px; padding: 0 4px 11px; }
.browser-bar i { width: 10px; height: 10px; border-radius: 50%; display: block; }
.browser-bar i:nth-child(1) { background: #ff5f57; }
.browser-bar i:nth-child(2) { background: #febc2e; }
.browser-bar i:nth-child(3) { background: #28c840; }
.browser-url {
  margin-left: 10px; flex: 1; height: 24px; border-radius: 999px;
  background: rgba(255, 255, 255, .08); color: #9fb8d8;
  font-size: .74rem; display: flex; align-items: center; padding: 0 12px;
  letter-spacing: .02em;
}
.browser-frame img { border-radius: 10px 10px 0 0; width: 100%; }
.hero-float {
  position: absolute; z-index: 2;
  display: flex; align-items: center; gap: .55rem;
  padding: 10px 16px; border-radius: 14px;
  background: rgba(9, 24, 45, .78); border: 1px solid rgba(255, 255, 255, .16);
  backdrop-filter: blur(8px); box-shadow: 0 16px 34px rgba(4, 16, 34, .45);
  font-size: .82rem; color: #dce9fb; white-space: nowrap;
}
.hero-float b { color: #fff; font-size: .95rem; }
.hero-float .dot { width: 8px; height: 8px; border-radius: 50%; background: #35e2a4; box-shadow: 0 0 0 4px rgba(53, 226, 164, .18); }
.hero-float-a { left: -26px; bottom: 84px; }
.hero-float-b { right: -18px; top: 56px; }

.hero-stats {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 20px; margin-top: 52px; padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, .14);
}
.hero-stats b { display: block; font-size: 1.72rem; letter-spacing: .01em; }
.hero-stats span { color: #9db6d6; font-size: .86rem; }

/* 屏幕高度不足时逐级收紧，保证首屏（含统计条）不需要滚动 */
@media (min-width: 861px) and (max-height: 940px) {
  .hero { padding: 46px 0 40px; }
  .hero-stats { margin-top: 38px; padding-top: 24px; }
  .hero h1 { font-size: clamp(1.68rem, 2.35vw, 2.12rem); }
  .hero-actions { margin-top: 26px; }
  .hero-points { margin-top: 22px; }
}
@media (min-width: 861px) and (max-height: 840px) {
  .hero { padding: 32px 0 30px; }
  .hero h1 { margin: 14px 0 12px; font-size: clamp(1.55rem, 2.15vw, 1.9rem); }
  .hero-lead { font-size: .95rem; }
  .hero-actions { margin-top: 20px; }
  .hero-points { margin-top: 16px; }
  .hero-stats { margin-top: 26px; padding-top: 20px; }
  .hero-visual { max-width: 560px; margin-left: auto; width: 100%; }
}
@media (min-width: 861px) and (max-height: 730px) {
  .hero { padding: 22px 0 22px; }
  .hero-tag { padding: 5px 12px; font-size: .74rem; }
  .hero-points { display: none; }
  .hero-stats { margin-top: 18px; padding-top: 14px; }
  .hero-stats b { font-size: 1.4rem; }
  .hero-stats span { font-size: .8rem; }
  .hero-visual { max-width: 460px; }
}

/* ---------------- 通用区块 ---------------- */
.section { padding: 88px 0; }
/* 锚点跳转时避开吸顶导航：区块自带 88px 上内边距，这里只需少量偏移，
   否则「导航高度 + scroll-margin + 区块内边距」会叠出一大片留白 */
section[id], div[id] { scroll-margin-top: 16px; }
.section.alt { background: linear-gradient(180deg, #f7f9fd, #f1f6fc); }
.section.tight { padding: 72px 0; }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 52px; }
.section-head h2 { margin: 0 0 14px; font-size: clamp(1.55rem, 2.3vw, 2rem); }
.section-head p { color: var(--muted); font-size: 1rem; }
.kicker {
  color: var(--brand); font-size: .78rem; font-weight: 700;
  letter-spacing: .2em; text-transform: uppercase; margin-bottom: 12px;
}
.section-head .kicker { display: block; }

.grid { display: grid; gap: 22px; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(248px, 1fr)); }
/* 产品与服务：5 张卡片宽屏一行排开 */
.grid-5 { grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 16px; }
/* 一行 5 张时卡片更紧凑：内容已精简，保证一屏可读 */
.product-row .card { padding: 20px 18px; }
.product-row .card h3 { font-size: 1rem; margin-bottom: 7px; }
.product-row .card p { font-size: .85rem; line-height: 1.6; }
.product-row .ic-tile { width: 40px; height: 40px; border-radius: 12px; margin-bottom: 12px; }
.product-row .ic-tile svg { width: 20px; height: 20px; }
/* 窄屏逐级降列，避免卡片被压得过窄 */
@media (max-width: 1180px) { .grid-5 { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
@media (max-width: 820px)  { .grid-5 { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 560px)  { .grid-5 { grid-template-columns: 1fr; } }

.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px 26px;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #cfe0ff; }
.card h3 { margin: 0 0 8px; font-size: 1.06rem; }
.card p { color: var(--muted); font-size: .92rem; }
.ic-tile {
  width: 48px; height: 48px; border-radius: 14px; margin-bottom: 16px;
  background: linear-gradient(140deg, #e9f2ff, #dcecff);
  display: grid; place-items: center; color: var(--brand);
  border: 1px solid #d8e8ff;
}
.card:hover .ic-tile { background: linear-gradient(140deg, var(--brand), var(--brand-2)); color: #fff; border-color: transparent; }
/* 核心能力卡片：顶部配图（与产品/场景卡片同一套观感） */
/* 核心能力卡片：大图在上，文字（图标 + 标题 + 说明）配在图片下方 */
.card.feature {
  display: block;
  padding: 0;
  overflow: hidden;
}
.feature-photo {
  display: block; width: 100%; height: auto; aspect-ratio: 16 / 9;
  object-fit: cover; background: #eef3fb;
}
.feature-body { padding: 12px 16px 15px; }
.feature-head { display: flex; align-items: center; gap: 8px; margin-bottom: 6px; }
.feature-head .ic-tile {
  width: 28px; height: 28px; border-radius: 9px; margin-bottom: 0; flex: none;
}
.feature-head .ic-tile svg { width: 16px; height: 16px; }
.feature-head h3 { margin: 0; font-size: 1rem; }
.feature-body p { margin: 0; font-size: .85rem; line-height: 1.6; }
/* 核心能力：只压紧「6 张能力卡片」这一块（图片 + 图标标题 + 说明一屏可看全），
   下面的「平台界面」与「接入方式」保持原有排版，不做压缩。 */
#features .section-head { margin-bottom: 20px; }

/* 特性小列表（卡片内） */
.ticks { margin-top: 14px; display: grid; gap: 7px; }
.ticks li { display: flex; gap: .5rem; color: var(--ink-2); font-size: .88rem; }
.ticks svg { flex: none; margin-top: 5px; color: var(--brand); }

/* ---------------- 平台预览（图文交错） ---------------- */
.split {
  display: grid; grid-template-columns: .92fr 1.08fr;
  gap: 56px; align-items: center;
}
.split + .split { margin-top: 76px; }
.split.rev .split-copy { order: 2; }
.split-copy h3 { margin: 0 0 14px; font-size: clamp(1.35rem, 1.9vw, 1.7rem); }
.split-copy > p { color: var(--muted); }
.shot {
  border-radius: 16px; overflow: hidden; border: 1px solid rgba(12, 38, 80, .1);
  box-shadow: var(--shadow-lg); background: #0a1728;
}
.shot img { width: 100%; }

/* ---------------- 接入拓扑 ---------------- */
.flow { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.flow-step {
  position: relative; background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px 24px;
}
.flow-step:not(:last-child)::after {
  content: ''; position: absolute; top: 39px; right: -22px; width: 22px; height: 2px;
  background: linear-gradient(90deg, #c8daf7, #e6eefb);
}
.flow-head { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.flow-head .step-no { margin-bottom: 0; }
.flow-head h4 { margin: 0; }
.flow-step .step-no {
  display: inline-flex; align-items: center; justify-content: center;
  width: 26px; height: 26px; border-radius: 8px; margin-bottom: 14px;
  background: #eaf2ff; color: var(--brand); font-size: .78rem; font-weight: 700;
}
.flow-step h4 { margin: 0 0 8px; font-size: 1rem; }
.flow-step p { color: var(--muted); font-size: .88rem; }
.flow-step .chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 12px; }
.flow-step .chips span {
  padding: 3px 10px; border-radius: 999px; background: var(--soft);
  border: 1px solid var(--line); color: var(--ink-2); font-size: .76rem;
}
/* 与核心能力合并后的紧凑版接入流程 */
.flow-compact .flow-step { padding: 20px 20px; }
.flow-compact .flow-step p { font-size: .86rem; }
.flow-compact .flow-step:not(:last-child)::after { top: 32px; }

/* ---------------- 应用场景 ---------------- */
.scene {
  display: block; padding: 0; overflow: hidden;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  transition: border-color .2s, transform .2s, box-shadow .2s;
}
.scene:hover { transform: translateY(-3px); border-color: #cfe0ff; box-shadow: var(--shadow-sm); }
.scene-photo {
  display: block; width: 100%; height: auto; aspect-ratio: 16 / 9;
  object-fit: cover; background: #eef3fb;
}
.scene-body { display: flex; gap: 16px; align-items: flex-start; padding: 22px 22px 24px; }
.scene .ic-tile { margin-bottom: 0; flex: none; }
.scene h3 { margin: 0 0 6px; font-size: 1.02rem; }
.scene p { color: var(--muted); font-size: .9rem; }

/* ---------------- 产业布局 ---------------- */
.plant { display: flex; flex-direction: column; }
.plant-tag {
  align-self: flex-start;
  padding: 3px 11px; border-radius: 999px; margin-bottom: 13px;
  background: #eaf3ff; border: 1px solid #d7e7ff;
  color: var(--brand); font-size: .74rem; font-weight: 600; letter-spacing: .04em;
}
.plant h3 { margin: 0 0 5px; font-size: 1rem; line-height: 1.45; }
.plant .plant-role { color: var(--brand); font-size: .84rem; font-weight: 600; margin-bottom: 14px; }
.plant .ticks { margin-top: auto; }
.plant-addr {
  margin-top: 13px; padding-top: 11px;
  border-top: 1px dashed var(--line);
  color: var(--muted); font-size: .79rem;
}

.cap-strip {
  margin-top: 24px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
  padding: 26px 30px; border-radius: var(--radius); color: #fff;
  background:
    radial-gradient(560px 260px at 88% 8%, rgba(34, 176, 255, .34), transparent 62%),
    linear-gradient(135deg, #07213f, #0c3d80 72%, #0a52a8);
  box-shadow: var(--shadow);
}
.cap-strip b { display: block; font-size: 1.5rem; letter-spacing: .01em; }
.cap-strip span { color: #b8cce7; font-size: .82rem; }

/* ---------------- 企业简介 ---------------- */
.about-grid { display: grid; grid-template-columns: 1.12fr 1fr; gap: 48px; align-items: stretch; }
.about-grid p { color: var(--ink-2); margin: 0 0 14px; }
.about-stats { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; margin-top: 24px; }
/* 与最下方图片底边对齐：数据框吸到左列底部 */
.about-copy .about-stats { margin-top: auto; padding-top: 24px; }
.about-stats div {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: 16px 18px; box-shadow: var(--shadow-sm);
}
.about-stats b { display: block; font-size: 1.42rem; color: var(--brand); letter-spacing: .01em; }
.about-stats span { color: var(--muted); font-size: .81rem; }

/* 软硬件实力图片拼图 */
.about-media { display: grid; gap: 14px; grid-template-rows: auto auto 1fr; }
.about-media-shot {
  position: relative; margin: 0; overflow: hidden;
  border-radius: 16px; background: #0a1728;
  box-shadow: var(--shadow); border: 1px solid rgba(12, 38, 80, .08);
  min-height: 0;   /* 允许按容器高度压缩，避免把整列撑高 */
}
.about-media-shot img {
  position: absolute; inset: 0;
  width: 100%; height: 100%; object-fit: cover; display: block;
}
.about-media-item1 { aspect-ratio: 931 / 275; }
.about-media-item2 { aspect-ratio: 984 / 314; }
/* 桌面端由最后一行（1fr）决定高度，让底边精确对齐左侧数据框；
   单列堆叠时再按原图比例显示 */
.about-media-wide { aspect-ratio: auto; }

/* 左侧文字列改为纵向弹性布局，让数据框贴住列底，与最下方图片底边齐平 */
.about-copy { display: flex; flex-direction: column; }
.about-media-shot figcaption {
  position: absolute; left: 0; right: 0; bottom: 0;
  padding: 26px 14px 11px; font-size: .78rem; color: #eaf3ff;
  background: linear-gradient(180deg, rgba(6, 20, 38, 0), rgba(6, 20, 38, .88));
}

/* ---------------- 联系我们 ---------------- */
.contact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 22px; }
.contact-grid .card h3 { font-size: .96rem; color: var(--muted); font-weight: 600; }
.contact-grid .card p { color: var(--ink); font-size: .96rem; margin-top: 4px; }
.contact-grid .card a { color: var(--brand); font-weight: 600; }
.contact-grid .card a:hover { text-decoration: underline; }

/* 联系方式：左侧信息卡 + 右侧微信二维码 */
.contact-layout { display: grid; grid-template-columns: 1.4fr .8fr; gap: 24px; align-items: stretch; }
/* 卡片行等分列高，让最下排卡片的底边与右侧二维码卡片底边齐平 */
.contact-list {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(258px, 1fr));
  gap: 18px; align-content: stretch; grid-auto-rows: 1fr;
}
.contact-item {
  display: flex; gap: 14px; align-items: flex-start;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 20px;
}
.contact-item .ic-tile { margin-bottom: 0; width: 42px; height: 42px; border-radius: 12px; flex: none; }
.contact-item h3 { margin: 0 0 4px; font-size: .86rem; color: var(--muted); font-weight: 600; }
.contact-item p { color: var(--ink); font-size: .95rem; word-break: break-word; }
.contact-item p { line-height: 1.5; }
.contact-item a { color: var(--brand); font-weight: 600; }
.contact-item a:hover { text-decoration: underline; }
.contact-qr {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  /* 高度略小于左侧信息卡列表：外层网格是 align-items:stretch，
     这样二维码卡片会被拉成与左侧等高，两块底部自动齐平。 */
  text-align: center; gap: 4px; padding: 18px 20px;
}
.contact-qr img {
  width: 100%; max-width: 190px; height: auto; border-radius: 12px;
  border: 1px solid var(--line); background: #fff;
}
.contact-qr h3 { margin: 12px 0 2px; font-size: .98rem; }
.contact-qr p { color: var(--muted); font-size: .84rem; }

/* 联系我们区块收紧：减少与上方区块之间的留白、以及标题与卡片之间的间距 */
#contact { padding-top: 24px; }
#contact .section-head { margin-bottom: 32px; }

/* ---------------- CTA 横幅 ---------------- */
.cta-wrap { padding: 0 0 88px; }
.cta-band {
  position: relative; overflow: hidden;
  border-radius: 26px; padding: 50px 54px; color: #fff;
  background:
    radial-gradient(600px 300px at 88% 10%, rgba(34, 176, 255, .38), transparent 62%),
    linear-gradient(135deg, #07213f, #0c3d80 72%, #0a52a8);
  display: flex; flex-wrap: wrap; gap: 28px; align-items: center; justify-content: space-between;
  box-shadow: var(--shadow-lg);
}
.cta-band::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: 40px 40px;
  mask-image: radial-gradient(circle at 80% 20%, #000 10%, transparent 70%);
  -webkit-mask-image: radial-gradient(circle at 80% 20%, #000 10%, transparent 70%);
}
.cta-band > * { position: relative; z-index: 1; }
.cta-copy h2 { margin: 0 0 10px; font-size: clamp(1.4rem, 2.1vw, 1.85rem); }
.cta-copy p { color: #b8cce7; }
.cta-actions { display: flex; flex-wrap: wrap; gap: 14px; }

/* ---------------- 页脚 ---------------- */
.site-footer { background: #061120; color: #92a6c1; padding: 58px 0 28px; font-size: .88rem; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 34px; }
.footer-brand {
  display: flex; align-items: center; gap: 10px;
  color: #fff; font-weight: 700; font-size: 1.04rem; margin-bottom: 10px;
}
.footer-brand .brand-badge {
  --badge-size: 30px;
  box-shadow: none;
}
.footer-about { max-width: 320px; color: #7f93ad; }
.footer-col h4 { color: #fff; font-size: .9rem; margin: 0 0 14px; letter-spacing: .04em; }
.footer-col a, .footer-col li { color: #92a6c1; display: block; padding: 4px 0; }
.footer-col a:hover { color: #fff; }
.footer-col li.nowrap { white-space: nowrap; }
/* 列表项里的链接必须行内显示，否则 block 会让号码另起一行 */
.footer-col li a { display: inline; padding: 0; }
.footer-bottom {
  margin-top: 40px; padding-top: 20px;
  /* 底部分割线 + 版权居中 */
  border-top: 1px solid rgba(255, 255, 255, .14);
  display: flex; flex-wrap: wrap; gap: 12px; justify-content: center;
  text-align: center;
  color: #6b7f9b; font-size: .82rem;
}
.footer-bottom a { color: #6b7f9b; text-decoration: none; }
.footer-bottom a:hover { color: #fff; text-decoration: underline; }

/* ---------------- 下载页 ---------------- */
.dl-hero {
  position: relative; overflow: hidden; color: #fff; padding: 72px 0 76px;
  background:
    radial-gradient(700px 380px at 80% 0%, rgba(34, 176, 255, .3), transparent 60%),
    linear-gradient(150deg, #04101f, #0a2a5e 70%, #0b3f86);
}
.dl-hero h1 { margin: 0 0 12px; font-size: clamp(1.6rem, 2.6vw, 2.1rem); }
.dl-hero p { color: #b6c9e4; max-width: 680px; }
.dl-hero .hero-tag { margin-bottom: 18px; }
/* 卡片上浮压住页首横幅：需要提升层级，否则会被 .dl-hero 盖住顶部 */
.dl-body { position: relative; z-index: 2; margin-top: -42px; }
.dl-card {
  background: #fff; border: 1px solid var(--line); border-radius: 20px;
  padding: 34px 32px; box-shadow: var(--shadow);
  display: flex; flex-wrap: wrap; gap: 26px; align-items: center; justify-content: space-between;
}
.dl-meta { min-width: 280px; flex: 1 1 420px; }
.dl-meta h3 { margin: 0 0 8px; font-size: 1.2rem; }
.dl-meta .tag {
  display: inline-block; padding: 3px 12px; border-radius: 999px;
  background: #eaf3ff; color: var(--brand); font-size: .74rem;
  margin-left: 10px; vertical-align: middle; font-weight: 600;
}
.dl-version { color: var(--muted); font-size: .86rem; }
.dl-list { margin-top: 16px; display: grid; gap: 9px; }
.dl-list li { display: flex; gap: .55rem; color: var(--ink-2); font-size: .92rem; }
.dl-list svg { flex: none; margin-top: 5px; color: #17b26a; }
.dl-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.btn-download {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: 14px 28px; border-radius: 12px; font-weight: 600; color: #fff;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  box-shadow: 0 12px 26px rgba(29, 111, 232, .3);
  transition: transform .16s, box-shadow .16s;
}
.btn-download:hover { transform: translateY(-2px); box-shadow: 0 16px 32px rgba(29, 111, 232, .38); }
.btn-secondary {
  display: inline-flex; align-items: center; padding: 14px 24px; border-radius: 12px;
  border: 1px solid #d7e2f0; color: var(--ink-2); font-weight: 600; background: #fff;
  transition: border-color .16s, color .16s;
}
.btn-secondary:hover { border-color: var(--brand); color: var(--brand); }
.step-card { position: relative; padding-top: 30px; }
.step-card .step-no {
  position: absolute; top: 22px; right: 24px;
  font-size: 2.1rem; font-weight: 800; color: #eef4ff; line-height: 1;
}
.note-list { color: var(--muted); font-size: .92rem; display: grid; gap: 10px; }

/* ---------------- 滚动进场动画 ---------------- */
/* 仅在 JS 可用时隐藏待进场元素，脚本被禁用时内容照常可见 */
html.js .reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s cubic-bezier(.2, .7, .3, 1); }
html.js .reveal.in { opacity: 1; transform: none; }

/* ---------------- 响应式 ---------------- */
@media (max-width: 1080px) {
  .hero-float { display: none; }
  .split { grid-template-columns: 1fr; gap: 32px; }
  .split.rev .split-copy { order: 0; }
  .flow { grid-template-columns: repeat(2, 1fr); }
  .flow-step:nth-child(2)::after { display: none; }
  .about-grid { grid-template-columns: 1fr; gap: 34px; }
  /* 单列堆叠时图片按自身比例显示（此时没有左列高度可对齐） */
  .about-media { grid-template-rows: auto auto auto; }
  .about-media-wide { aspect-ratio: 2030 / 974; }
  .about-copy .about-stats { margin-top: 24px; padding-top: 0; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 28px; }
  .contact-layout { grid-template-columns: 1fr; }
}

/* 导航项较多：中等宽度下收紧间距，避免文字换行或被挤压 */
@media (max-width: 1200px) {
  .nav-links a { padding: 7px 9px; font-size: .87rem; }
  .nav-cta { padding: 9px 15px !important; margin-left: 4px; font-size: .87rem; }
}

/* 首屏保持双列到 980px：更窄的窗口才会堆叠，避免中等宽度下首屏被拉长 */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; gap: 42px; }
  .hero-visual { max-width: 720px; margin: 0 auto; width: 100%; }
}

@media (max-width: 860px) {
  .nav-toggle { display: grid; }
  .nav-links {
    position: absolute; left: 0; right: 0; top: 72px;
    flex-direction: column; align-items: stretch; gap: 4px;
    background: #fff; border-bottom: 1px solid var(--line);
    padding: 12px 18px 18px; box-shadow: 0 18px 30px rgba(12, 38, 80, .1);
    display: none;
  }
  .site-header.nav-open .nav-links { display: flex; }
  .nav-links a { padding: 12px 14px; font-size: .93rem; }
  .nav-links a.nav-cta { margin-left: 0; text-align: center; }
  .hero { padding: 62px 0 56px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 22px 18px; margin-top: 48px; }
  .section { padding: 66px 0; }
  .section-head { margin-bottom: 38px; }
  .cta-band { padding: 36px 30px; border-radius: 20px; }
  .cta-wrap { padding-bottom: 66px; }
  .dl-card { padding: 26px 24px; }
  .dl-body { margin-top: -30px; }
  .cap-strip { grid-template-columns: repeat(2, 1fr); gap: 16px; padding: 22px 22px; }
  .cap-strip b { font-size: 1.3rem; }
  .brand { gap: 12px; }
  .site-nav .brand-badge { --badge-size: 40px; }
  .brand-name { font-size: 17px; }
  .brand-sub { font-size: 9.5px; }
}

@media (max-width: 620px) {
  body { font-size: 15.5px; }
  .wrap { padding: 0 18px; }
  .flow { grid-template-columns: 1fr; }
  .flow-step::after { display: none; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-actions .btn-primary-lg, .hero-actions .btn-ghost-lg { width: 100%; justify-content: center; }
  .cta-actions { width: 100%; }
  .cta-actions a { flex: 1 1 auto; justify-content: center; }
  .about-stats { grid-template-columns: 1fr 1fr; }
  .contact-qr img { max-width: 200px; }
  .site-nav .brand-badge { --badge-size: 36px; }
  .brand-name { font-size: 16px; }
  .brand-sub { font-size: 9px; }
  .brand-lockup { gap: 3px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  html.js .reveal { opacity: 1; transform: none; transition: none; }
  * { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

/* ============================================================
   产品与服务：BMS 保护板实拍滚动（右 → 左匀速，鼠标悬停暂停）
   缩略图统一 520x390 框内等比缩放（不裁切、不放大），
   卡片用 object-fit: contain 保证不同长宽比的板子都完整清晰。
   ============================================================ */
.board-marquee {
  position: relative;
  margin: 1.5rem 0 2.4rem;
  overflow: hidden;
  /* 两侧渐隐，避免卡片被硬边切断 */
  -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 5%, #000 95%, transparent 100%);
  mask-image: linear-gradient(90deg, transparent 0, #000 5%, #000 95%, transparent 100%);
}
.board-track {
  display: flex;
  width: max-content;
  /* 18 张卡片（9 张 × 2 份），单张宽 300 + 间距 14 = 314px；
     translateX(-50%) 正好等于 9 张卡的宽度 → 无缝循环；
     60s / 9 张 ≈ 6.7s 过一张，与原先速度一致 */
  animation: board-scroll 60s linear infinite;
  will-change: transform;
}
.board-track:hover { animation-play-state: paused; }
.board-card {
  flex: none;
  width: 300px;
  margin: 0 14px 0 0;
  background: #fff;
  border: 1px solid rgba(15, 42, 92, .10);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 6px 18px rgba(16, 42, 90, .07);
}
.board-card img {
  display: block;
  width: 100%;
  height: 200px;
  padding: 8px;
  box-sizing: border-box;
  object-fit: contain;      /* 完整显示整块板，不裁切 */
  background: #f7f9fc;
}
.board-card figcaption {
  padding: 8px 12px 10px;
  font-size: 12.5px;
  line-height: 1.4;
  color: var(--ink-2);
  text-align: center;
  white-space: nowrap;
}
@keyframes board-scroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}
@media (max-width: 720px) {
  .board-card { width: 220px; }
  .board-card img { height: 150px; }
  .board-card figcaption { font-size: 11.5px; }
}