/* 芯海智控官网主题 corp
   版式取向：细导航 + 整幅下拉面板、居中大标题、暗色大卡片横带、浅灰分区。
   只用黑白灰 + 一个蓝，靠留白和卡片图像做深浅对比，不靠边框和分割线。 */

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--c-light);
  color: var(--c-dark);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img, svg { max-width: 100%; display: block; }
h1, h2, h3, h4 { font-family: var(--font-display); line-height: 1.25; margin: 0; letter-spacing: -0.01em; }
p { margin: 0; }
.wrap { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 32px; }

/* ---------- 顶部细导航（通栏、加高，左导航 + 右功能入口） ---------- */
.topbar {
  position: sticky; top: 0; z-index: 60;
  background: rgba(255,255,255,.94);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--c-line);
}
.nav-in { display: flex; align-items: center; gap: 30px; height: 72px; max-width: none; padding: 0 24px; }
.brand { display: flex; align-items: center; gap: 9px; font-weight: 600; font-size: 16px; white-space: nowrap; }
.brand-mark {
  width: 26px; height: 26px; border-radius: 7px; background: var(--c-dark);
  color: #fff; display: grid; place-items: center; font-size: 12px; font-weight: 700; letter-spacing: .02em;
}
.brand-sub { color: #6b7280; font-weight: 400; font-size: 13px; }

.nav { display: flex; align-items: center; gap: 2px; margin-left: 10px; }
.nav-item { position: relative; }
.nav-item > a, .nav-item > button {
  display: inline-flex; align-items: center; gap: 5px;
  font: inherit; font-size: 15px; color: #3c4043; background: none; border: 0;
  padding: 9px 13px; border-radius: 8px; cursor: pointer; white-space: nowrap;
}
.nav-item > a:hover, .nav-item > button:hover { background: var(--c-muted-bg, #f6f7f9); color: var(--c-dark); }
.nav-item.active > a, .nav-item.active > button { color: var(--c-dark); font-weight: 500; }
.caret { width: 8px; height: 8px; border-right: 1.5px solid currentColor; border-bottom: 1.5px solid currentColor; transform: rotate(45deg) translateY(-1px); opacity: .55; transition: transform .18s; }
.nav-item.open .caret { transform: rotate(-135deg) translateY(-1px); }

.nav-right { margin-left: auto; display: flex; align-items: center; gap: 22px; }
.nav-link-quiet { font-size: 15px; color: #3c4043; display: inline-flex; align-items: center; gap: 6px; }
.nav-link-quiet:hover { color: var(--c-accent); }

/* ---------- 整幅下拉面板 ---------- */
.panel {
  position: fixed; left: 0; right: 0; top: 72px;
  background: #fff; border-bottom: 1px solid var(--c-line);
  box-shadow: 0 24px 48px -24px rgba(11,13,18,.18);
  opacity: 0; visibility: hidden; transform: translateY(-6px);
  transition: opacity .18s ease, transform .18s ease, visibility .18s;
  z-index: 55;
}
.nav-item.open .panel { opacity: 1; visibility: visible; transform: translateY(0); }
.panel-in { display: grid; grid-template-columns: 300px 1fr; gap: 0; padding: 34px 0 40px; }
.panel-rail { border-right: 1px solid var(--c-line); padding-right: 28px; }
.panel-rail-title { font-size: 13px; color: #80868b; margin-bottom: 14px; letter-spacing: .04em; }
.rail-list { display: flex; flex-direction: column; gap: 2px; }
.rail-list a { padding: 9px 14px; border-radius: 999px; font-size: 14.5px; color: #3c4043; }
.rail-list a:hover { background: var(--c-muted-bg, #f6f7f9); }
.rail-list a.on { background: #eef1f5; color: var(--c-dark); font-weight: 500; }
.panel-body { padding-left: 40px; }
.panel-head { display: flex; align-items: baseline; justify-content: space-between; gap: 20px; margin-bottom: 22px; }
.panel-head h3 { font-size: 20px; font-weight: 600; }
.panel-head h3 a:hover { color: var(--c-accent); }
.panel-head p { font-size: 13.5px; color: #6b7280; margin-top: 6px; }
.panel-grid { display: grid; grid-template-columns: repeat(4, minmax(0,1fr)); gap: 26px 30px; }
.panel-grid.cols-3 { grid-template-columns: repeat(3, minmax(0,1fr)); }
.p-item { display: block; }
.p-item .p-ico {
  width: 26px; height: 26px; border-radius: 7px; background: var(--c-muted-bg, #f6f7f9);
  display: grid; place-items: center; margin-bottom: 10px; font-size: 14px;
}
.p-item strong { display: block; font-size: 14.5px; font-weight: 500; margin-bottom: 4px; }
.p-item span { display: block; font-size: 13px; color: #6b7280; line-height: 1.55; }
.p-item:hover strong { color: var(--c-accent); }
.panel-cta { display: inline-flex; align-items: center; gap: 8px; margin-top: 26px; font-size: 14px; color: var(--c-accent); font-weight: 500; }
.panel-close { position: absolute; right: 28px; top: 16px; border: 0; background: none; font-size: 22px; color: #9aa0a6; cursor: pointer; line-height: 1; }

/* ---------- 按钮 ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; height: 44px; padding: 0 22px; border-radius: 999px; font-size: 15px; font-weight: 500; transition: .18s; border: 1px solid transparent; }
.btn-primary { background: var(--c-accent); color: #fff; }
.btn-primary:hover { filter: brightness(1.08); }
.btn-ghost { background: #fff; color: var(--c-dark); border-color: #d5d9e0; }
.btn-ghost:hover { background: var(--c-muted-bg, #f6f7f9); }
.btn-dark { background: var(--c-dark); color: #fff; }
.btn-sm { height: 36px; padding: 0 16px; font-size: 14px; }

/* ---------- Hero ---------- */
.hero { padding: 96px 0 72px; text-align: center; }
.hero-eyebrow { font-size: 13.5px; color: #80868b; letter-spacing: .06em; margin-bottom: 22px; }
.hero h1 { font-size: clamp(38px, 5.4vw, 68px); font-weight: 700; letter-spacing: -0.03em; }
.hero-sub { max-width: 720px; margin: 24px auto 0; font-size: clamp(15px, 1.4vw, 18px); color: #5f6368; line-height: 1.75; }
.hero-cta { display: flex; gap: 12px; justify-content: center; margin-top: 36px; flex-wrap: wrap; }
.hero-note { margin-top: 26px; font-size: 13px; color: #9aa0a6; }

/* ---------- 暗色卡片横带 ---------- */
.cardband { padding: 8px 0 72px; }
.band-track {
  display: grid; grid-auto-flow: column; grid-auto-columns: minmax(300px, 1fr);
  gap: 16px; overflow-x: auto; scroll-snap-type: x mandatory;
  padding: 4px 32px 18px; margin: 0 auto; max-width: var(--container);
  scrollbar-width: thin;
}
.band-track::-webkit-scrollbar { height: 6px; }
.band-track::-webkit-scrollbar-thumb { background: #d7dbe2; border-radius: 99px; }
/* 桌面端四张卡刚好铺满整幅，不做横向滚动；窄屏退回可横滑 */
@media (min-width: 1100px) {
  .band-track { grid-auto-flow: row; grid-template-columns: repeat(4, minmax(0, 1fr)); overflow: visible; }
}
.card {
  position: relative; display: flex; flex-direction: column; justify-content: flex-end;
  min-height: 340px; padding: 26px; border-radius: var(--radius); overflow: hidden;
  background: #0b0d12; color: #fff; scroll-snap-align: start; isolation: isolate;
}
.card img.card-art { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; z-index: -2; opacity: .95; }
.card::after { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(180deg, rgba(11,13,18,0) 34%, rgba(11,13,18,.82) 100%); }
.card .kicker { font-size: 12.5px; color: rgba(255,255,255,.72); letter-spacing: .05em; margin-bottom: 8px; }
.card h3 { font-size: 21px; font-weight: 600; letter-spacing: -0.01em; }
.card p { margin-top: 8px; font-size: 13.5px; color: rgba(255,255,255,.72); line-height: 1.6; }
.card:hover img.card-art { transform: scale(1.03); }
.card img.card-art { transition: transform .5s ease; }

/* ---------- 通用分区 ---------- */
.section { padding: 88px 0; }
.section.tint { background: var(--c-muted-bg, #f6f7f9); }
.section-head { max-width: 760px; margin-bottom: 48px; }
.section-head h2 { font-size: clamp(26px, 2.9vw, 38px); font-weight: 700; letter-spacing: -0.02em; }
.section-head p { margin-top: 14px; color: #5f6368; font-size: 16px; }
.eyebrow { font-size: 13px; color: var(--c-accent); font-weight: 500; letter-spacing: .05em; margin-bottom: 12px; }

/* 事实块（三点） */
.facts { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 28px; }
.fact { padding-top: 22px; border-top: 1px solid var(--c-line); }
.fact .num { font-size: 30px; font-weight: 700; letter-spacing: -0.02em; }
.fact h3 { font-size: 16px; font-weight: 600; margin: 8px 0 8px; }
.fact p { font-size: 14px; color: #5f6368; line-height: 1.7; }

/* 产品网格 */
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 20px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 20px; }
.tile { background: #fff; border: 1px solid var(--c-line); border-radius: 16px; padding: 26px; transition: .18s; }
.tile:hover { border-color: #cfd4dc; box-shadow: 0 12px 28px -18px rgba(11,13,18,.28); }
.tile .tag { display: inline-block; font-size: 12px; color: #5f6368; background: var(--c-muted-bg, #f6f7f9); border-radius: 999px; padding: 3px 10px; margin-bottom: 14px; }
.tile h3 { font-size: 18px; font-weight: 600; margin-bottom: 8px; }
.tile p { font-size: 14px; color: #5f6368; }
.tile .meta { margin-top: 16px; font-size: 13px; color: #80868b; }

/* 案例带 */
.case-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.case { display: grid; grid-template-columns: 64px 1fr; gap: 20px; padding: 26px; border-radius: 16px; background: #fff; border: 1px solid var(--c-line); }
.case .badge { width: 44px; height: 44px; border-radius: 12px; background: var(--c-dark); color: #fff; display: grid; place-items: center; font-size: 13px; font-weight: 600; }
.case h3 { font-size: 17px; font-weight: 600; margin-bottom: 6px; }
.case p { font-size: 14px; color: #5f6368; }
.case .outcome { margin-top: 12px; font-size: 13px; color: #80868b; }

/* CTA 区 */
.cta-band { padding: 80px 0; }
.cta-box { background: var(--c-dark); color: #fff; border-radius: 24px; padding: 64px 56px; display: flex; align-items: center; justify-content: space-between; gap: 32px; flex-wrap: wrap; }
.cta-box h2 { font-size: clamp(24px, 2.6vw, 34px); font-weight: 700; letter-spacing: -0.02em; }
.cta-box p { margin-top: 12px; color: rgba(255,255,255,.7); font-size: 15px; max-width: 620px; }
.cta-box .btn-ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,.35); }
.cta-box .btn-ghost:hover { background: rgba(255,255,255,.08); }

/* ---------- 内页 ---------- */
.page-hero { padding: 72px 0 40px; border-bottom: 1px solid var(--c-line); }
.page-hero h1 { font-size: clamp(30px, 3.6vw, 46px); font-weight: 700; letter-spacing: -0.025em; }
.page-hero p { margin-top: 16px; color: #5f6368; font-size: 16px; max-width: 760px; }
.breadcrumb { font-size: 13px; color: #9aa0a6; margin-bottom: 18px; }
.breadcrumb a:hover { color: var(--c-accent); }

.detail { display: grid; grid-template-columns: 240px 1fr; gap: 48px; padding: 56px 0; border-bottom: 1px solid var(--c-line); }
.detail:last-child { border-bottom: 0; }
.detail-aside h2 { font-size: 20px; font-weight: 600; }
.detail-aside .kicker { font-size: 12.5px; color: #80868b; letter-spacing: .05em; margin-bottom: 10px; }
.detail-body h3 { font-size: 15px; font-weight: 600; margin: 26px 0 8px; color: #202124; }
.detail-body h3:first-child { margin-top: 0; }
.detail-body p { font-size: 15px; color: #4a4f55; line-height: 1.8; }
.detail-body ul { margin: 8px 0 0; padding-left: 20px; color: #4a4f55; font-size: 15px; line-height: 1.9; }

.prose { max-width: 800px; }
.prose h2 { font-size: 24px; font-weight: 700; margin: 44px 0 14px; }
.prose h3 { font-size: 17px; font-weight: 600; margin: 28px 0 10px; }
.prose p { margin: 12px 0; font-size: 15.5px; color: #3c4043; line-height: 1.85; }
.prose ul, .prose ol { padding-left: 22px; color: #3c4043; line-height: 1.9; }
.prose table { width: 100%; border-collapse: collapse; margin: 20px 0; font-size: 14.5px; }
.prose th, .prose td { border-bottom: 1px solid var(--c-line); padding: 10px 12px; text-align: left; vertical-align: top; }
.prose th { font-weight: 600; background: var(--c-muted-bg, #f6f7f9); }
.prose blockquote { margin: 20px 0; padding: 14px 20px; border-left: 3px solid var(--c-accent); background: var(--c-muted-bg, #f6f7f9); color: #3c4043; }

/* 白皮书列表 */
.paper-list { display: grid; gap: 16px; }
.paper { display: grid; grid-template-columns: 1fr auto; gap: 24px; align-items: center; padding: 24px 26px; border: 1px solid var(--c-line); border-radius: 14px; transition: .18s; }
.paper:hover { border-color: #cfd4dc; box-shadow: 0 12px 28px -18px rgba(11,13,18,.28); }
.paper h3 { font-size: 17px; font-weight: 600; }
.paper p { margin-top: 6px; font-size: 14px; color: #5f6368; }
.paper .meta { font-size: 12.5px; color: #80868b; margin-top: 10px; }
.paper .go { font-size: 14px; color: var(--c-accent); font-weight: 500; white-space: nowrap; }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--c-line); padding: 56px 0 40px; margin-top: 40px; }
.footer-cols { display: grid; grid-template-columns: 1.6fr repeat(3, 1fr); gap: 40px; }
.footer h4 { font-size: 13px; color: #80868b; font-weight: 500; margin-bottom: 14px; letter-spacing: .04em; }
.footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 9px; }
.footer ul a { font-size: 14px; color: #3c4043; }
.footer ul a:hover { color: var(--c-accent); }
.footer-brand p { font-size: 13.5px; color: #6b7280; margin-top: 14px; max-width: 320px; line-height: 1.7; }
.footer-bottom { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; justify-content: space-between; margin-top: 28px; padding-top: 22px; border-top: 1px solid var(--c-line); font-size: 13px; color: #80868b; }
.footer-bottom .links { display: flex; gap: 16px; flex-wrap: wrap; }

/* 法律条：关于 / 隐私权 / 网站条款 / 订阅简报 + 语言选择（对标 Google 的页脚条） */
.footer-legal { display: flex; flex-wrap: wrap; gap: 18px 40px; align-items: center; justify-content: space-between; margin-top: 40px; font-size: 13.5px; color: #5f6368; }
.legal-links { display: flex; flex-wrap: wrap; gap: 26px; }
.legal-links a:hover { color: var(--c-accent); }
.lang-pick { position: relative; }
.lang-pick summary { list-style: none; cursor: pointer; display: inline-flex; align-items: center; gap: 7px; color: #5f6368; }
.lang-pick summary::-webkit-details-marker { display: none; }
.lang-pick summary::after { content: ""; width: 6px; height: 6px; border-right: 1.4px solid currentColor; border-bottom: 1.4px solid currentColor; transform: rotate(45deg) translateY(-1px); }
.lang-pick[open] summary::after { transform: rotate(-135deg) translateY(-1px); }
.lang-menu { position: absolute; right: 0; bottom: 28px; min-width: 190px; background: #fff; border: 1px solid var(--c-line); border-radius: 10px; box-shadow: 0 16px 32px -18px rgba(11,13,18,.3); padding: 6px; display: grid; gap: 2px; z-index: 5; }
.lang-menu a { padding: 8px 12px; border-radius: 6px; font-size: 13.5px; color: #3c4043; }
.lang-menu a:hover { background: var(--c-muted-bg, #f6f7f9); }

.nav-toggle { display: none; border: 0; background: none; font-size: 20px; cursor: pointer; color: var(--c-dark); margin-left: auto; }
/* 导航项多的时候，次要项在中等屏收起（避免挤压右侧功能入口） */
@media (max-width: 1320px) { .nav-optional { display: none; } }

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .panel-in { grid-template-columns: 1fr; }
  .panel-rail { border-right: 0; border-bottom: 1px solid var(--c-line); padding: 0 0 16px; margin-bottom: 20px; }
  .panel-body { padding-left: 0; }
  .panel-grid, .panel-grid.cols-3 { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .footer-cols { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 860px) {
  .wrap { padding: 0 20px; }
  .nav { display: none; }
  .nav.mobile-open { display: flex; position: fixed; left: 0; right: 0; top: 64px; background: #fff; flex-direction: column; align-items: stretch; padding: 12px 20px 24px; border-bottom: 1px solid var(--c-line); gap: 2px; max-height: calc(100vh - 64px); overflow: auto; }
  .nav.mobile-open .panel { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; border: 0; display: none; }
  .nav.mobile-open .nav-item.open .panel { display: block; }
  .nav.mobile-open .panel-in { padding: 12px 0 18px; }
  /* 手机端顶栏只留品牌 + 汉堡 + 主 CTA，其余挤不下 */
  .nav-in { height: 64px; gap: 12px; padding: 0 20px; }
  .brand-sub, .nav-link-quiet { display: none; }
  .nav-right { gap: 8px; }
  .nav-toggle { display: inline-flex; }
  .hero h1 { font-size: clamp(30px, 8.4vw, 40px); }
  .facts, .grid-3, .grid-2, .case-row { grid-template-columns: 1fr; }
  .detail { grid-template-columns: 1fr; gap: 18px; }
  .hero { padding: 64px 0 48px; }
  .section { padding: 60px 0; }
  .cta-box { padding: 40px 28px; }
  .paper { grid-template-columns: 1fr; }
  .footer-cols { grid-template-columns: 1fr; }
}