/* 第五纪信息科技官网 — 全局样式 */

:root {
  --ink: #0e1a2b;
  --ink-2: #334966;
  --ink-3: #6b7f96;
  --line: #e3e9f0;
  --bg: #ffffff;
  --bg-2: #f6f9fc;
  --brand: #1668dc;
  --brand-dark: #0f4fa8;
  --brand-soft: #e8f1fe;
  --teal: #129e8f;
  --amber: #d98613;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(14, 26, 43, .04), 0 8px 24px rgba(14, 26, 43, .06);
  --shadow-lg: 0 2px 4px rgba(14, 26, 43, .05), 0 16px 48px rgba(14, 26, 43, .10);
  --maxw: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  color: var(--ink);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: var(--brand); text-decoration: none; }
a:hover { color: var(--brand-dark); }

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

/* ---------- 顶栏 ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .88);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav-in { display: flex; align-items: center; gap: 32px; height: 66px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--ink); letter-spacing: .5px; }
.brand:hover { color: var(--ink); }
.brand .mark {
  width: 30px; height: 30px; border-radius: 8px; flex: none;
  background: linear-gradient(135deg, var(--brand), var(--teal));
  color: #fff; font-size: 15px; font-weight: 800;
  display: grid; place-items: center;
}
.nav-links { display: flex; gap: 28px; margin-left: auto; align-items: center; }
.nav-links a { color: var(--ink-2); font-size: 15px; font-weight: 500; }
.nav-links a:hover, .nav-links a.on { color: var(--brand); }
.nav-cta {
  background: var(--brand); color: #fff !important; padding: 8px 18px;
  border-radius: 999px; font-size: 14px !important;
}
.nav-cta:hover { background: var(--brand-dark); }
.nav-toggle { display: none; margin-left: auto; background: none; border: 0; font-size: 24px; color: var(--ink-2); cursor: pointer; }

/* ---------- 通用区块 ---------- */
.section { padding: 84px 0; }
.section.alt { background: var(--bg-2); }
.eyebrow {
  font-size: 13px; font-weight: 700; letter-spacing: 2px; text-transform: uppercase;
  color: var(--brand); margin: 0 0 12px;
}
h1, h2, h3, h4 { line-height: 1.35; margin: 0 0 16px; letter-spacing: -.2px; }
h1 { font-size: 44px; font-weight: 800; }
h2 { font-size: 32px; font-weight: 750; }
h3 { font-size: 19px; font-weight: 700; }
.lead { font-size: 17px; color: var(--ink-2); max-width: 760px; }
.muted { color: var(--ink-3); }
.center { text-align: center; }
.center .lead { margin-left: auto; margin-right: auto; }

.btn {
  display: inline-block; padding: 12px 26px; border-radius: 999px;
  font-weight: 600; font-size: 15px; border: 1px solid transparent;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 6px 18px rgba(22, 104, 220, .28); }
.btn-primary:hover { background: var(--brand-dark); color: #fff; }
.btn-ghost { border-color: var(--line); color: var(--ink-2); background: #fff; }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }
.btn-row { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 28px; }

/* ---------- Hero ---------- */
.hero {
  padding: 96px 0 88px;
  background:
    radial-gradient(900px 420px at 88% -10%, #e3efff 0%, rgba(227, 239, 255, 0) 70%),
    radial-gradient(700px 380px at 4% 8%, #e6f7f4 0%, rgba(230, 247, 244, 0) 70%);
  border-bottom: 1px solid var(--line);
}
.hero h1 { max-width: 15em; }
.hero .lead { font-size: 18px; margin-top: 6px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; }
.tag {
  font-size: 13px; padding: 5px 14px; border-radius: 999px;
  background: #fff; border: 1px solid var(--line); color: var(--ink-2);
}

/* ---------- 卡片网格 ---------- */
.grid { display: grid; gap: 20px; }
.g2 { grid-template-columns: repeat(2, 1fr); }
.g3 { grid-template-columns: repeat(3, 1fr); }
.g4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow);
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: #d3e0ee; }
.card h3 { margin-bottom: 8px; }
.card p { margin: 0; color: var(--ink-2); font-size: 15px; }
.card .kicker { font-size: 12px; font-weight: 700; letter-spacing: 1.4px; color: var(--teal); text-transform: uppercase; margin-bottom: 10px; }
.card ul { margin: 14px 0 0; padding-left: 18px; color: var(--ink-2); font-size: 14.5px; }
.card ul li { margin-bottom: 5px; }

/* 产品详情大卡 */
.prod {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 36px; box-shadow: var(--shadow); margin-bottom: 22px;
}
.prod-head { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; margin-bottom: 6px; }
.prod-head h3 { font-size: 23px; margin: 0; }
.prod-head .en { font-size: 13px; color: var(--ink-3); letter-spacing: 1px; }
.badge {
  font-size: 12px; font-weight: 600; padding: 3px 11px; border-radius: 999px;
  background: var(--brand-soft); color: var(--brand-dark);
}
.badge.teal { background: #e2f6f3; color: #0b7d71; }
.badge.amber { background: #fdf1de; color: #a8650a; }
.prod .desc { color: var(--ink-2); margin: 10px 0 20px; }
.feat { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px 26px; }
.feat div { font-size: 14.5px; color: var(--ink-2); padding-left: 18px; position: relative; }
.feat div::before {
  content: ""; position: absolute; left: 0; top: 11px;
  width: 6px; height: 6px; border-radius: 50%; background: var(--brand);
}

/* ---------- 数据条 ---------- */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; text-align: center; }
.stat .n { font-size: 40px; font-weight: 800; color: var(--brand); line-height: 1.2; }
.stat .t { font-size: 14px; color: var(--ink-3); }

/* ---------- 时间线 ---------- */
.timeline { border-left: 2px solid var(--line); padding-left: 30px; margin-left: 6px; }
.tl-item { position: relative; padding-bottom: 34px; }
.tl-item::before {
  content: ""; position: absolute; left: -37px; top: 8px;
  width: 12px; height: 12px; border-radius: 50%;
  background: #fff; border: 3px solid var(--brand);
}
.tl-item .en { font-size: 12px; letter-spacing: 2px; text-transform: uppercase; color: var(--teal); font-weight: 700; }
.tl-item h3 { margin: 2px 0 8px; }
.tl-item p { margin: 0; color: var(--ink-2); font-size: 15px; }

/* ---------- 定价 ---------- */
.price-wrap { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; max-width: 780px; margin: 0 auto; }
.price {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px; text-align: center; position: relative;
}
.price.hot { border-color: var(--brand); box-shadow: 0 10px 40px rgba(22, 104, 220, .14); }
.price .flag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--brand); color: #fff; font-size: 12px; font-weight: 600;
  padding: 4px 16px; border-radius: 999px; white-space: nowrap;
}
.price .name { font-size: 16px; font-weight: 700; }
.price .amount { font-size: 46px; font-weight: 800; color: var(--ink); margin: 10px 0 2px; }
.price .amount small { font-size: 17px; font-weight: 600; color: var(--ink-3); }
.price .unit { font-size: 14px; color: var(--ink-3); }
.price .note { font-size: 13.5px; color: var(--ink-3); margin-top: 14px; }

/* ---------- 联系 / 二维码 ---------- */
.qr-card { text-align: center; }
.qr-card img {
  width: 210px; height: 210px; object-fit: contain; margin: 0 auto 14px;
  border: 1px solid var(--line); border-radius: 12px; padding: 8px; background: #fff;
}
.contact-list { list-style: none; padding: 0; margin: 0; }
.contact-list li { display: flex; gap: 14px; padding: 14px 0; border-bottom: 1px dashed var(--line); font-size: 15px; }
.contact-list li:last-child { border-bottom: 0; }
.contact-list .k { color: var(--ink-3); width: 92px; flex: none; }
.contact-list .v { color: var(--ink); font-weight: 500; }

/* ---------- 页脚 ---------- */
.footer { background: #0e1a2b; color: #93a6bd; padding: 56px 0 28px; font-size: 14.5px; }
.footer a { color: #93a6bd; }
.footer a:hover { color: #fff; }
.footer h4 { color: #fff; font-size: 15px; margin: 0 0 14px; }
.foot-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 36px; }
.foot-grid p { margin: 0 0 8px; }
.foot-links { list-style: none; margin: 0; padding: 0; }
.foot-links li { margin-bottom: 8px; }
.foot-bottom {
  margin-top: 42px; padding-top: 22px; border-top: 1px solid #1e2f46;
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 13.5px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .g3, .g4, .stats, .feat, .price-wrap, .foot-grid { grid-template-columns: repeat(2, 1fr); }
  h1 { font-size: 34px; }
  h2 { font-size: 26px; }
  .section { padding: 60px 0; }
  .hero { padding: 64px 0 56px; }
}
@media (max-width: 640px) {
  .nav-links {
    display: none; position: absolute; top: 66px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    flex-direction: column; gap: 0; padding: 8px 24px 18px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 11px 0; width: 100%; }
  .nav-toggle { display: block; }
  .g2, .g3, .g4, .stats, .feat, .price-wrap, .foot-grid { grid-template-columns: 1fr; }
  h1 { font-size: 28px; }
  .prod { padding: 24px; }
}