/* ===========================================================
   board.车载连接器.中国 — 独立设计系统 v1.0
   设计调性：高端科技 · 板端/域控连接器
   本文件为本站原创，禁止跨子域复用
   =========================================================== */

:root {
  --bg: #ffffff;
  --bg-alt: #f3f6fb;
  --bg-deep: #07112a;
  --bg-deep-2: #0c1c3e;
  --ink: #0f1f3a;
  --ink-soft: #41506b;
  --ink-faint: #7888a3;
  --brand: #0b3d91;
  --brand-2: #1450c4;
  --accent: #00c2a8;
  --accent-ink: #006b5c;
  --amber: #ff7a18;
  --line: #e4eaf3;
  --line-strong: #cdd8ea;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow-sm: 0 1px 2px rgba(13, 28, 62, .06), 0 4px 14px rgba(13, 28, 62, .06);
  --shadow-md: 0 8px 30px rgba(11, 61, 145, .12);
  --shadow-lg: 0 18px 50px rgba(7, 17, 42, .22);
  --maxw: 1180px;
  --h2-inset: 16px;
  --header-h: 68px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--brand-2); text-decoration: none; }
a:hover { color: var(--accent-ink); }
h1, h2, h3, h4 { color: var(--ink); line-height: 1.28; font-weight: 700; }

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

/* ---------- 顶部固定导航 ---------- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; height: var(--header-h);
  background: rgba(7, 17, 42, .82);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
  z-index: 1000;
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: var(--header-h); max-width: var(--maxw); margin: 0 auto; padding: 0 24px;
}
.brand { display: flex; align-items: center; gap: 11px; color: #fff; font-weight: 700; letter-spacing: .3px; }
.brand .logo-mark {
  width: 30px; height: 30px; border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--brand-2));
  display: grid; place-items: center; color: #fff; font-weight: 800; font-size: 15px;
  box-shadow: 0 0 16px rgba(0, 194, 168, .5);
}
.brand small { display: block; font-size: 11px; font-weight: 500; color: #9fb2d4; letter-spacing: 1px; }
.nav-links { display: flex; align-items: center; gap: 4px; list-style: none; margin: 0; padding: 0; }
.nav-links > li > a {
  color: #d6e0f2; padding: 9px 14px; border-radius: 8px; font-size: 14.5px; font-weight: 500;
  display: inline-flex; align-items: center; gap: 6px; transition: .18s;
}
.nav-links > li > a:hover { color: #fff; background: rgba(255, 255, 255, .08); }
.nav-links > li > a.active { color: #fff; background: rgba(0, 194, 168, .18); }
/* 下拉分类菜单 */
.has-menu { position: relative; }
.has-menu .submenu {
  position: absolute; top: calc(100% + 8px); left: 0; min-width: 220px;
  background: #0c1c3e; border: 1px solid rgba(255,255,255,.1); border-radius: 12px;
  padding: 8px; box-shadow: var(--shadow-lg); opacity: 0; visibility: hidden; transform: translateY(6px);
  transition: .18s; list-style: none; margin: 0;
}
.has-menu:hover .submenu { opacity: 1; visibility: visible; transform: translateY(0); }
.submenu li a { display: block; padding: 9px 12px; border-radius: 8px; color: #cdd8ea; font-size: 14px; }
.submenu li a:hover { background: rgba(0,194,168,.16); color: #fff; }
.nav-toggle { display: none; background: none; border: 0; color: #fff; font-size: 24px; cursor: pointer; }

/* ---------- 首屏 Hero ---------- */
.hero {
  position: relative; margin-top: var(--header-h); padding: 96px 0 84px;
  background:
    radial-gradient(1200px 520px at 78% -10%, rgba(0,194,168,.20), transparent 60%),
    radial-gradient(900px 460px at 8% 0%, rgba(20,80,196,.30), transparent 55%),
    linear-gradient(160deg, var(--bg-deep), var(--bg-deep-2));
  color: #eaf1ff; overflow: hidden;
}
.hero::after {
  content: ""; position: absolute; inset: 0;
  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(70% 70% at 50% 30%, #000 30%, transparent 100%);
}
.hero .container { position: relative; z-index: 1; }
.hero .eyebrow {
  display: inline-block; font-size: 13px; letter-spacing: 2px; color: var(--accent);
  border: 1px solid rgba(0,194,168,.4); padding: 5px 14px; border-radius: 999px; margin-bottom: 22px;
}
.hero h1 { color: #fff; font-size: clamp(30px, 4.4vw, 50px); margin: 0 0 18px; letter-spacing: .3px; }
.hero h1 .hl { color: var(--accent); }
.hero p.lead { font-size: 17px; color: #b9c8e6; max-width: 660px; margin: 0 0 30px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 13px 24px; border-radius: 10px;
  font-weight: 600; font-size: 15px; cursor: pointer; border: 1px solid transparent; transition: .18s;
}
.btn-primary { background: linear-gradient(135deg, var(--accent), #06e0c2); color: #042; box-shadow: 0 10px 26px rgba(0,194,168,.34); }
.btn-primary:hover { color: #021; transform: translateY(-2px); }
.btn-ghost { background: rgba(255,255,255,.06); border-color: rgba(255,255,255,.2); color: #eaf1ff; }
.btn-ghost:hover { background: rgba(255,255,255,.14); color: #fff; }

.hero-stats { display: flex; gap: 38px; margin-top: 52px; flex-wrap: wrap; }
.hero-stats .stat .num { font-size: 30px; font-weight: 800; color: #fff; }
.hero-stats .stat .num span { color: var(--accent); }
.hero-stats .stat .lbl { font-size: 13px; color: #9fb2d4; }

/* ---------- 通用区块 ---------- */
.section { padding: 76px 0; }
.section.alt { background: var(--bg-alt); }
.section-head { max-width: 720px; margin: 0 auto 44px; text-align: center; }
.section-head .kicker { color: var(--accent-ink); font-weight: 700; letter-spacing: 1.5px; font-size: 13px; }
.section-head h2 { font-size: clamp(24px, 3vw, 34px); margin: 10px 0 12px; }
.section-head p { color: var(--ink-soft); margin: 0; }

.grid { display: grid; gap: 22px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow-sm); transition: .2s; position: relative; overflow: hidden;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--line-strong); }
.card .ico {
  width: 46px; height: 46px; border-radius: 12px; display: grid; place-items: center;
  background: linear-gradient(135deg, rgba(0,194,168,.16), rgba(20,80,196,.16));
  color: var(--brand); font-size: 22px; margin-bottom: 16px;
}
.card h3 { font-size: 18px; margin: 0 0 10px; }
.card p { color: var(--ink-soft); font-size: 14.5px; margin: 0; }
.card .tag { display: inline-block; margin-top: 14px; font-size: 12.5px; color: var(--accent-ink); font-weight: 600; }

/* 产品/文章列表卡片 */
.tile { background:#fff; border:1px solid var(--line); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); transition:.2s; display:flex; flex-direction:column; }
.tile:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.tile .thumb { height: 150px; background: linear-gradient(135deg, var(--bg-deep-2), var(--brand)); position: relative; }
.tile .thumb span { position:absolute; left:16px; bottom:14px; color:#fff; font-weight:700; font-size:13px; letter-spacing:1px; opacity:.85; }
.tile .body { padding: 20px; flex:1; display:flex; flex-direction:column; }
.tile .body h3 { font-size: 17px; margin: 0 0 8px; }
.tile .body p { color: var(--ink-soft); font-size: 14px; margin: 0 0 14px; flex:1; }
.tile .meta { font-size: 12.5px; color: var(--ink-faint); display:flex; gap:10px; align-items:center; }
.pill { font-size: 12px; padding: 3px 10px; border-radius: 999px; background: var(--bg-alt); color: var(--brand); font-weight: 600; }
.pill.accent { background: rgba(0,194,168,.14); color: var(--accent-ink); }

/* ---------- 面包屑（左缘与正文 H2 严格对齐） ---------- */
.breadcrumb {
  font-size: 13.5px; color: var(--ink-faint); padding: 22px 0 6px;
  margin-left: var(--h2-inset);
}
.breadcrumb a { color: var(--ink-soft); }
.breadcrumb a:hover { color: var(--brand-2); }
.breadcrumb .sep { margin: 0 9px; color: var(--line-strong); }
.breadcrumb .cur { color: var(--ink); font-weight: 600; }

/* ---------- 文章/产品详情布局 ---------- */
.doc-layout { display: grid; grid-template-columns: minmax(0,1fr) 248px; gap: 44px; align-items: start; padding: 18px 0 80px; }
.doc-main { min-width: 0; max-width: 760px; }
.doc-main h1 { font-size: clamp(26px, 3.2vw, 36px); margin: 6px 0 18px; padding-left: var(--h2-inset); }
/* 摘要块 */
.abstract {
  margin: 0 0 22px; padding: 20px 22px; border-left: 4px solid var(--accent);
  background: linear-gradient(90deg, rgba(0,194,168,.08), rgba(20,80,196,.05));
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0; padding-left: calc(var(--h2-inset) + 22px);
}
.abstract p { margin: 0; color: var(--ink); font-size: 15.5px; }
/* 关键词行 */
.kw-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; padding-left: 0; margin-bottom: 26px; }
.kw { font-size: 12.5px; color: var(--brand); background: rgba(20,80,196,.08); border:1px solid rgba(20,80,196,.14); padding: 4px 11px; border-radius: 999px; }
.update-time { padding-left: var(--h2-inset); font-size: 13px; color: var(--ink-faint); margin-bottom: 26px; }

/* 正文 H2/H3 左缘对齐 */
.doc-main h2 { font-size: 23px; margin: 40px 0 16px; padding-left: var(--h2-inset); position: relative; }
.doc-main h2::before { content:""; position:absolute; left:0; top:6px; bottom:6px; width:4px; border-radius:3px; background: linear-gradient(var(--accent), var(--brand-2)); }
.doc-main h3 { font-size: 18px; margin: 26px 0 12px; padding-left: var(--h2-inset); }
.doc-main p { padding-left: var(--h2-inset); margin: 0 0 16px; color: var(--ink-soft); }
.doc-main ul, .doc-main ol { padding-left: calc(var(--h2-inset) + 22px); margin: 0 0 16px; color: var(--ink-soft); }
.doc-main li { margin-bottom: 8px; }

/* 参数 / 对比表 */
table.spec { width: 100%; border-collapse: collapse; margin: 8px 0 22px; font-size: 14.5px; }
table.spec th, table.spec td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--line); }
table.spec thead th { background: var(--bg-deep); color: #fff; font-weight: 600; }
table.spec tbody tr:nth-child(even) { background: var(--bg-alt); }
table.spec tbody tr:hover { background: rgba(0,194,168,.07); }
table.spec td:first-child { font-weight: 600; color: var(--ink); }

/* 结论块 */
.conclusion { margin: 18px 0 26px; padding: 18px 20px; background: var(--bg-alt); border:1px solid var(--line); border-radius: var(--radius-sm); padding-left: calc(var(--h2-inset) + 20px); }
.conclusion h4 { margin: 0 0 10px; font-size: 15px; color: var(--accent-ink); }
.conclusion ol { padding-left: 22px; margin: 0; }
.conclusion li { margin-bottom: 6px; color: var(--ink); }

/* 实践经验 callout */
.callout { margin: 18px 0; padding: 16px 18px; border:1px dashed var(--accent); background: rgba(0,194,168,.06); border-radius: var(--radius-sm); padding-left: calc(var(--h2-inset) + 18px); }
.callout strong { color: var(--accent-ink); }

/* 选型建议高亮卡片 */
.selection-tip {
  margin: 18px 0 26px; padding: 18px 22px;
  background: linear-gradient(135deg, rgba(0,194,168,.10), rgba(20,80,196,.06));
  border: 1px solid rgba(0,194,168,.25); border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}
.selection-tip h2 { margin: 0 0 10px; padding-left: 0; font-size: 20px; }
.selection-tip h2::before { display: none; }
.selection-tip p { padding-left: 0; margin: 0; color: var(--ink); font-size: 15px; }

/* FAQ */
.faq details { border: 1px solid var(--line); border-radius: var(--radius-sm); margin-bottom: 12px; background: #fff; overflow: hidden; }
.faq summary { cursor: pointer; padding: 15px 18px; font-weight: 600; color: var(--ink); list-style: none; display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-size: 22px; color: var(--brand); transition: .2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details .ans { padding: 0 18px 16px; color: var(--ink-soft); font-size: 14.5px; }

/* 相关阅读 */
.related { margin-top: 34px; padding-top: 26px; border-top: 1px solid var(--line); }
.related h3 { padding-left: var(--h2-inset); font-size: 18px; margin: 0 0 16px; }
.related ul { list-style: none; padding: 0 0 0 var(--h2-inset); margin: 0; }
.related li { padding: 12px 0; border-bottom: 1px dashed var(--line); }
.related li a { font-weight: 600; }
.related li span { display: block; color: var(--ink-faint); font-size: 13px; margin-top: 3px; }

/* ---------- 右侧 TOC 悬浮 ---------- */
.toc-aside { position: sticky; top: calc(var(--header-h) + 18px); max-height: calc(100vh - 110px); overflow-y: auto; }
.toc-aside .toc-title { font-size: 13px; font-weight: 700; color: var(--ink-faint); letter-spacing: 1px; text-transform: uppercase; margin-bottom: 12px; }
.toc-aside ul { list-style: none; margin: 0; padding: 0; border-left: 2px solid var(--line); }
.toc-aside li a { display: block; padding: 7px 14px; font-size: 13.5px; color: var(--ink-soft); border-left: 2px solid transparent; margin-left: -2px; transition: .15s; }
.toc-aside li a:hover, .toc-aside li a.active { color: var(--brand); border-color: var(--accent); font-weight: 600; }

/* ---------- 列表页（左侧分类 + 右侧内容） ---------- */
.list-layout { display: grid; grid-template-columns: 234px minmax(0,1fr); gap: 40px; padding: 18px 0 80px; align-items: start; }
.cat-side { position: sticky; top: calc(var(--header-h) + 18px); }
.cat-side h3 { font-size: 14px; color: var(--ink-faint); letter-spacing: 1px; text-transform: uppercase; margin: 0 0 12px; }
ul.category-list { list-style: none; margin: 0; padding: 0; }
ul.category-list li a {
  display: block; padding: 11px 14px; border-radius: 9px; color: var(--ink-soft); font-weight: 500; font-size: 14.5px; transition: .15s;
}
ul.category-list li a:hover { background: var(--bg-alt); color: var(--brand); }
ul.category-list li a.active { background: rgba(0,194,168,.14); color: var(--accent-ink); font-weight: 700; }
.cat-content h1 { font-size: clamp(24px,3vw,32px); margin: 4px 0 8px; }
.cat-content .cat-desc { color: var(--ink-soft); margin: 0 0 28px; }

/* ---------- 悬浮工具胶囊 ---------- */
.float-capsule {
  position: fixed; right: 18px; top: 50%; transform: translateY(-50%);
  display: flex; flex-direction: column; gap: 12px; z-index: 900;
}
.capsule-btn {
  width: 56px; height: 56px; border-radius: 999px; border: 0; cursor: pointer;
  background: linear-gradient(135deg, var(--brand-2), var(--accent));
  color: #fff; display: grid; place-items: center; box-shadow: 0 8px 22px rgba(11,61,145,.4);
  transition: .2s; position: relative;
}
.capsule-btn:hover { transform: scale(1.07); box-shadow: 0 12px 28px rgba(0,194,168,.5); }
.capsule-btn svg { width: 24px; height: 24px; }
.capsule-label { position: absolute; right: 64px; white-space: nowrap; background: var(--bg-deep); color: #fff; font-size: 12.5px; padding: 6px 12px; border-radius: 8px; opacity: 0; pointer-events: none; transition: .2s; }
.capsule-btn:hover .capsule-label { opacity: 1; }

/* 名片弹窗 */
.wechat-modal { position: fixed; inset: 0; background: rgba(7,17,42,.55); display: none; align-items: center; justify-content: center; z-index: 1100; padding: 20px; }
.wechat-modal.open { display: flex; }
.wechat-modal .card-box { background: #fff; border-radius: 16px; padding: 14px; box-shadow: var(--shadow-lg); width: 300px; }
.wechat-modal .card-box img { width: 300px; height: 500px; object-fit: contain; border-radius: 10px; background: #f6f8fc; }
.wechat-modal .close { display:block; text-align:center; margin-top:10px; color: var(--ink-soft); font-size: 14px; cursor:pointer; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--bg-deep); color: #b9c8e6; padding: 56px 0 28px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 32px; }
.site-footer h4 { color: #fff; font-size: 15px; margin: 0 0 16px; }
.site-footer a { color: #b9c8e6; display: block; padding: 5px 0; font-size: 14px; }
.site-footer a:hover { color: var(--accent); }
.site-footer .about p { font-size: 14px; color: #9fb2d4; max-width: 320px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); margin-top: 38px; padding-top: 20px; font-size: 13px; color: #7e90b3; display:flex; justify-content: center; flex-wrap: wrap; gap: 10px; }

/* ---------- 关于/通用单栏页面 ---------- */
.doc-single { max-width: 880px; padding: 18px 0 80px; }
.doc-single h1 { font-size: clamp(26px, 3.2vw, 34px); margin: 6px 0 18px; padding-left: var(--h2-inset); }
.doc-single h2 { font-size: 22px; margin: 36px 0 14px; padding-left: var(--h2-inset); position: relative; }
.doc-single h2::before { content:""; position:absolute; left:0; top:6px; bottom:6px; width:4px; border-radius:3px; background: linear-gradient(var(--accent), var(--brand-2)); }
.doc-single p { padding-left: var(--h2-inset); margin: 0 0 16px; color: var(--ink-soft); }
.doc-single ul { padding-left: calc(var(--h2-inset) + 22px); margin: 0 0 16px; color: var(--ink-soft); }
.doc-single li { margin-bottom: 8px; }
.doc-single .abstract { margin: 0 0 22px; padding: 20px 22px; border-left: 4px solid var(--accent); background: linear-gradient(90deg, rgba(0,194,168,.08), rgba(20,80,196,.05)); border-radius: 0 var(--radius-sm) var(--radius-sm) 0; padding-left: calc(var(--h2-inset) + 22px); }
.doc-single .abstract p { padding-left: 0; margin: 0; color: var(--ink); }

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .doc-layout { grid-template-columns: 1fr; }
  .toc-aside { display: none; }
  .list-layout { grid-template-columns: 1fr; }
  .cat-side { position: static; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .nav-links { display: none; position: absolute; top: var(--header-h); left: 0; right: 0; flex-direction: column; background: var(--bg-deep-2); padding: 14px; gap: 4px; border-bottom: 1px solid rgba(255,255,255,.1); }
  .nav-links.open { display: flex; }
  .nav-links > li > a { width: 100%; }
  .has-menu .submenu { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; background: transparent; border: 0; padding-left: 12px; }
  .nav-toggle { display: block; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 56px; }
  .hero-stats { gap: 24px; }
  .footer-grid { grid-template-columns: 1fr; }
  .breadcrumb, .kw-row, .update-time, .doc-main h1, .doc-main h2, .doc-main h3, .doc-main p,
  .abstract, .conclusion, .callout, .related h3, .related ul, .page-wrap h2, .page-wrap p, .page-wrap ul { padding-left: 8px; }
  .float-capsule { right: 10px; }
}