/* ============================================================
   诺信四站统一设计系统 v2.0
   风格：浅色大图工业集团风（对标申菱环境/宁德时代/美的集团）
   原则：白底大图、每屏一主题、大字留白、实拍为王、零占位残留
   ============================================================ */

:root {
  --ink: #0D2B4E;        /* 深工业蓝：大标题 */
  --brand: #0A5FBF;       /* 品牌蓝：链接/强调 */
  --deep: #0A3D7A;        /* 深蓝：CTA带/页脚底 */
  --accent: #F57C1F;      /* 橙：主CTA */
  --accent-hover: #E06A10;
  --bg: #FFFFFF;
  --soft: #F4F7FA;        /* 浅灰区块底 */
  --line: #E4EAF1;
  --text: #33475B;
  --muted: #74859A;
  --shadow: 0 10px 30px rgba(13, 43, 78, .08);
  --shadow-lg: 0 18px 50px rgba(13, 43, 78, .14);
  --radius: 10px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; transition: all .25s; }
ul { list-style: none; }
.wrap { width: min(1200px, 92%); margin: 0 auto; }

/* ---------- 顶部信息条 ---------- */
.topbar { background: var(--deep); color: rgba(255,255,255,.85); font-size: 13px; }
.topbar .wrap { display: flex; justify-content: space-between; align-items: center; height: 36px; }
.topbar span { letter-spacing: .5px; }
.topbar b { color: #fff; font-weight: 600; margin-left: 6px; }

/* ---------- 主导航 ---------- */
.site-header {
  background: rgba(255,255,255,.97);
  position: sticky; top: 0; z-index: 100;
  box-shadow: 0 2px 14px rgba(13,43,78,.07);
}
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 76px; }
.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark {
  width: 44px; height: 44px; border-radius: 8px;
  background: linear-gradient(135deg, var(--brand), var(--deep));
  color: #fff; font-weight: 800; font-size: 20px;
  display: flex; align-items: center; justify-content: center; letter-spacing: 1px;
}
.logo-name { line-height: 1.2; }
.logo-name .cn { font-size: 21px; font-weight: 700; color: var(--ink); letter-spacing: 2px; }
.logo-name .en { font-size: 11px; color: var(--muted); letter-spacing: 1.6px; text-transform: uppercase; }
.nav { display: flex; gap: 34px; align-items: center; }
.nav a { font-size: 16px; color: var(--ink); font-weight: 500; position: relative; padding: 6px 0; }
.nav a:hover, .nav a.on { color: var(--brand); }
.nav a:hover::after, .nav a.on::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -8px; height: 3px;
  background: var(--accent); border-radius: 2px;
}
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px; border-radius: 6px;
  font-size: 16px; font-weight: 600; cursor: pointer; border: none;
}
.btn-accent { background: var(--accent); color: #fff; box-shadow: 0 6px 18px rgba(245,124,31,.35); }
.btn-accent:hover { background: var(--accent-hover); transform: translateY(-2px); }
.btn-ghost { background: transparent; color: #fff; border: 1.5px solid rgba(255,255,255,.7); }
.btn-ghost:hover { background: rgba(255,255,255,.12); border-color: #fff; }
.btn-blue { background: var(--brand); color: #fff; }
.btn-blue:hover { background: #084C9B; transform: translateY(-2px); }
.btn-nav { padding: 10px 24px; font-size: 15px; }

/* ---------- Hero 全幅大图 ---------- */
.hero {
  position: relative; min-height: 640px;
  display: flex; align-items: center;
  background-size: cover; background-position: center;
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(8,32,62,.70) 0%, rgba(10,61,122,.42) 45%, rgba(10,61,122,.10) 100%);
}
.hero .wrap { position: relative; z-index: 2; padding: 110px 0 130px; }
.hero-tag {
  display: inline-block; padding: 7px 18px; margin-bottom: 26px;
  background: rgba(255,255,255,.14); border: 1px solid rgba(255,255,255,.35);
  color: #fff; font-size: 14px; letter-spacing: 3px; border-radius: 4px;
  backdrop-filter: blur(4px);
}
.hero h1 {
  color: #fff; font-size: 52px; line-height: 1.3; font-weight: 700;
  max-width: 720px; letter-spacing: 1px; margin-bottom: 22px;
}
.hero h1 em { font-style: normal; color: #FFB56B; }
.hero-sub {
  color: rgba(255,255,255,.88); font-size: 19px; max-width: 640px;
  margin-bottom: 42px; line-height: 1.9;
}
.hero-btns { display: flex; gap: 18px; flex-wrap: wrap; }

/* hero 底部数字条 */
.hero-stats {
  position: absolute; left: 0; right: 0; bottom: 0; z-index: 3;
  background: rgba(255,255,255,.96);
  box-shadow: 0 -8px 30px rgba(8,32,62,.12);
}
.hero-stats .wrap { display: grid; grid-template-columns: repeat(4, 1fr); }
.hero-stats .item { text-align: center; padding: 26px 8px; border-right: 1px solid var(--line); }
.hero-stats .item:last-child { border-right: none; }
.hero-stats .num { font-size: 38px; font-weight: 800; color: var(--brand); font-family: Georgia, serif; }
.hero-stats .num i { font-style: normal; font-size: 20px; margin-left: 2px; }
.hero-stats .lab { font-size: 14px; color: var(--muted); margin-top: 4px; letter-spacing: 1px; }

/* ---------- 通用区块 ---------- */
.sec { padding: 96px 0; }
.sec.alt { background: var(--soft); }
.sec-head { text-align: center; max-width: 760px; margin: 0 auto 56px; }
.sec-no {
  font-size: 13px; color: var(--accent); letter-spacing: 4px;
  font-weight: 700; text-transform: uppercase; margin-bottom: 12px;
}
.sec-t { font-size: 36px; font-weight: 700; color: var(--ink); letter-spacing: 1px; line-height: 1.35; }
.sec-sub { font-size: 16.5px; color: var(--muted); margin-top: 14px; }
.sec-line { width: 56px; height: 4px; background: var(--accent); border-radius: 2px; margin: 22px auto 0; }

/* ---------- 产品卡网格 ---------- */
.grid { display: grid; gap: 28px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.card {
  background: #fff; border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow); transition: all .3s ease; border: 1px solid var(--line);
}
.card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); }
.card .pic { aspect-ratio: 4/3; overflow: hidden; background: #EEF2F7; }
.card .pic img { width: 100%; height: 100%; object-fit: cover; transition: transform .45s ease; }
.card:hover .pic img { transform: scale(1.06); }
.card .body { padding: 24px 24px 28px; }
.card .name { font-size: 19px; font-weight: 700; color: var(--ink); margin-bottom: 10px; }
.card .desc { font-size: 14.5px; color: var(--muted); line-height: 1.75; margin-bottom: 14px; min-height: 76px; }
.card .meta { font-size: 13.5px; color: var(--brand); font-weight: 600; display: flex; gap: 6px; align-items: center; }
.card .meta::after { content: "→"; margin-left: auto; transition: margin-left .25s; }
.card:hover .meta::after { margin-left: -2px; }

/* ---------- 场景大卡 ---------- */
.case-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.case {
  position: relative; border-radius: var(--radius); overflow: hidden;
  min-height: 300px; display: flex; align-items: flex-end;
  background-size: cover; background-position: center; box-shadow: var(--shadow);
  transition: all .3s ease;
}
.case:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.case::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(8,32,62,.88) 0%, rgba(8,32,62,.15) 55%, transparent 100%);
}
.case .info { position: relative; z-index: 2; padding: 26px; width: 100%; }
.case .info h3 { color: #fff; font-size: 20px; font-weight: 700; margin-bottom: 6px; }
.case .info p { color: rgba(255,255,255,.82); font-size: 14px; }
.case .badge {
  position: absolute; top: 18px; left: 18px; z-index: 2;
  background: var(--accent); color: #fff; font-size: 12.5px; font-weight: 600;
  padding: 5px 12px; border-radius: 4px; letter-spacing: 1px;
}

/* ---------- 双栏图文 ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.split .pic-box { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-lg); }
.split .pic-box img { width: 100%; height: 100%; object-fit: cover; }
.split h3 { font-size: 30px; color: var(--ink); font-weight: 700; margin-bottom: 18px; line-height: 1.4; }
.split p { color: var(--muted); margin-bottom: 16px; font-size: 15.5px; }
.check-list li {
  position: relative; padding-left: 34px; margin-bottom: 14px;
  font-size: 15.5px; color: var(--text);
}
.check-list li::before {
  content: "✓"; position: absolute; left: 0; top: 1px;
  width: 22px; height: 22px; border-radius: 50%;
  background: rgba(10,95,191,.1); color: var(--brand);
  font-size: 13px; font-weight: 800; display: flex; align-items: center; justify-content: center;
}

/* ---------- 业务板块卡（实物图版） ---------- */
.biz-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; }
.biz {
  background: #fff; border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--line); transition: all .3s ease; text-align: center;
}
.biz:hover { border-color: transparent; box-shadow: var(--shadow-lg); transform: translateY(-6px); }
.biz .pic { height: 148px; overflow: hidden; }
.biz .pic img { width: 100%; height: 100%; object-fit: cover; transition: transform .45s ease; }
.biz:hover .pic img { transform: scale(1.06); }
.biz .body { padding: 20px 18px 24px; }
.biz h3 { font-size: 17px; color: var(--ink); font-weight: 700; margin-bottom: 8px; line-height: 1.45; }
.biz p { font-size: 13px; color: var(--muted); line-height: 1.7; }

/* ---------- 基地分布 ---------- */
.base-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; }
.base {
  background: #fff; border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--line); transition: all .3s;
}
.base:hover { box-shadow: var(--shadow-lg); transform: translateY(-5px); }
.base .pic { height: 170px; background-size: cover; background-position: center; }
.base .body { padding: 20px 22px; }
.base .loc { font-size: 11px; color: var(--accent); letter-spacing: 2px; font-weight: 700; }
.base h3 { font-size: 18px; color: var(--ink); margin: 4px 0 6px; }
.base p { font-size: 13px; color: var(--muted); }

/* ---------- 资质墙 ---------- */
.cert-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 34px; }
.cert {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px; box-shadow: var(--shadow); transition: all .3s;
}
.cert:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.cert img { width: 100%; border-radius: 6px; aspect-ratio: 210/297; object-fit: contain; background: #FAFBFD; }
.cert p { text-align: center; font-size: 14.5px; color: var(--ink); font-weight: 600; margin-top: 14px; }

/* ---------- 流程步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(5, 1fr); gap: 0; counter-reset: step; }
.step { position: relative; text-align: center; padding: 0 14px; }
.step .no {
  width: 64px; height: 64px; margin: 0 auto 18px; border-radius: 50%;
  background: #fff; border: 2.5px solid var(--brand); color: var(--brand);
  font-size: 24px; font-weight: 800; display: flex; align-items: center; justify-content: center;
  box-shadow: 0 6px 18px rgba(10,95,191,.16);
}
.step:not(:last-child)::after {
  content: ""; position: absolute; top: 31px; left: calc(50% + 42px); right: calc(-50% + 42px);
  height: 2.5px; background: repeating-linear-gradient(to right, var(--brand) 0 8px, transparent 8px 14px);
}
.step h3 { font-size: 17px; color: var(--ink); font-weight: 700; margin-bottom: 8px; }
.step p { font-size: 13.5px; color: var(--muted); line-height: 1.7; }

/* ---------- 常见问题 ---------- */
.faq { max-width: 860px; margin: 0 auto; }
.faq details {
  background: #fff; border: 1px solid var(--line); border-radius: 8px;
  margin-bottom: 16px; overflow: hidden; transition: all .25s;
}
.faq details[open] { box-shadow: var(--shadow); border-color: rgba(10,95,191,.35); }
.faq summary {
  cursor: pointer; padding: 20px 26px; font-size: 16.5px; font-weight: 600; color: var(--ink);
  list-style: none; display: flex; align-items: center; justify-content: space-between;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--brand); font-size: 22px; font-weight: 700; }
.faq details[open] summary::after { content: "−"; }
.faq .a { padding: 0 26px 22px; color: var(--muted); font-size: 15px; line-height: 1.9; }

/* ---------- CTA 横带 ---------- */
.cta-band {
  background: linear-gradient(115deg, var(--deep) 0%, #0A5FBF 100%);
  padding: 78px 0; position: relative; overflow: hidden;
}
.cta-band::before {
  content: ""; position: absolute; right: -120px; top: -160px; width: 460px; height: 460px;
  border-radius: 50%; background: rgba(255,255,255,.06);
}
.cta-band::after {
  content: ""; position: absolute; left: -80px; bottom: -200px; width: 380px; height: 380px;
  border-radius: 50%; background: rgba(245,124,31,.14);
}
.cta-band .wrap { position: relative; z-index: 2; display: flex; align-items: center; justify-content: space-between; gap: 40px; flex-wrap: wrap; }
.cta-band h2 { color: #fff; font-size: 32px; font-weight: 700; letter-spacing: 1px; }
.cta-band p { color: rgba(255,255,255,.82); font-size: 16px; margin-top: 10px; }

/* ---------- 页脚 ---------- */
.site-footer { background: #0A1F3C; color: rgba(255,255,255,.72); padding: 66px 0 0; }
.foot-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.4fr; gap: 44px; padding-bottom: 46px; }
.foot-grid h4 { color: #fff; font-size: 16px; font-weight: 600; margin-bottom: 18px; letter-spacing: 1px; }
.foot-grid p, .foot-grid li { font-size: 14px; line-height: 2.1; }
.foot-grid a:hover { color: #fff; }
.foot-brand .logo-name .cn { color: #fff; }
.foot-brand .logo-name .en { color: rgba(255,255,255,.5); }
.foot-brand p { margin-top: 16px; font-size: 13.5px; color: rgba(255,255,255,.55); }
.foot-contact li { display: flex; gap: 10px; align-items: baseline; }
.foot-contact .ic { color: var(--accent); font-weight: 700; }
.foot-bottom {
  border-top: 1px solid rgba(255,255,255,.1); padding: 22px 0;
  display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
  font-size: 12.5px; color: rgba(255,255,255,.42);
}
.foot-sister { display: flex; gap: 22px; align-items: center; }
.foot-sister a { color: rgba(255,255,255,.55); font-size: 12.5px; }
.foot-sister a:hover { color: #fff; }

/* ---------- 视频容器（固定16:9，防跳动） ---------- */
.video-box {
  position: relative; width: 100%; aspect-ratio: 16 / 9;
  background: #0A1F3C; border-radius: 12px; overflow: hidden; box-shadow: var(--shadow-lg);
}
.video-box video { width: 100%; height: 100%; object-fit: cover; display: block; }
.video-box.video-plain { box-shadow: none; border-radius: 0; }

/* ---------- 浮动咨询 ---------- */
.float-cta {
  position: fixed; right: 26px; bottom: 30px; z-index: 90;
  display: flex; flex-direction: column; gap: 12px;
}
.float-cta a {
  width: 56px; height: 56px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font-size: 24px;
  color: #fff; box-shadow: 0 8px 22px rgba(13,43,78,.25);
}
.float-cta .tel { background: var(--accent); }
.float-cta .top { background: var(--deep); }

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .grid-4, .biz-grid, .base-grid, .steps { grid-template-columns: repeat(2, 1fr); gap: 30px 20px; }
  .case-grid { grid-template-columns: repeat(2, 1fr); }
  .hero h1 { font-size: 40px; }
  .split { grid-template-columns: 1fr; gap: 36px; }
}
@media (max-width: 720px) {
  .nav { display: none; }
  .grid-3, .grid-4, .case-grid, .cert-grid, .biz-grid, .base-grid, .steps { grid-template-columns: 1fr; }
  .step:not(:last-child)::after { display: none; }
  .hero { min-height: 520px; }
  .hero h1 { font-size: 32px; }
  .hero-stats .wrap { grid-template-columns: repeat(2, 1fr); }
  .hero-stats .item { border-bottom: 1px solid var(--line); }
  .sec { padding: 64px 0; }
  .sec-t { font-size: 27px; }
  .foot-grid { grid-template-columns: 1fr; gap: 30px; }
}