:root {
  --navy: #0f2740;
  --navy-deep: #081a2c;
  --teal: #16a394;
  --teal-bright: #36c6b6;
  --ink: #1c2b3a;
  --muted: #5b6b7c;
  --line: #e2e8ee;
  --bg: #ffffff;
  --bg-alt: #f5f8fa;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(15, 39, 64, 0.08);
}

* { 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", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

.container {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
  gap: 16px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark { width: 36px; height: 36px; flex: 0 0 auto; }
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-text strong { font-size: 16px; color: var(--navy); letter-spacing: 0.5px; }
.brand-text em {
  font-style: normal;
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0.6px;
}
.site-nav { display: flex; gap: 26px; }
.site-nav a {
  font-size: 15px;
  color: var(--ink);
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: color .2s, border-color .2s;
}
.site-nav a:hover { color: var(--teal); border-color: var(--teal); }

/* ---------- hero ---------- */
.hero {
  background: radial-gradient(1200px 500px at 80% -10%, #1d4b74 0%, var(--navy) 45%, var(--navy-deep) 100%);
  color: #fff;
  padding: 96px 0 104px;
}
.hero-eyebrow {
  margin: 0 0 18px;
  font-size: 13px;
  letter-spacing: 3px;
  color: var(--teal-bright);
  text-transform: uppercase;
}
.hero h1 {
  margin: 0 0 22px;
  font-size: clamp(30px, 5.4vw, 52px);
  line-height: 1.25;
  letter-spacing: 1px;
  font-weight: 700;
}
.hero-lead {
  margin: 0 0 36px;
  max-width: 620px;
  font-size: clamp(15px, 2.1vw, 18px);
  color: #c8d6e4;
}
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-block;
  padding: 13px 30px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  transition: transform .15s, background .2s, border-color .2s, color .2s;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--teal-bright); color: #05231f; }
.btn-primary:hover { background: #4ad7c7; }
.btn-ghost { border: 1px solid rgba(255, 255, 255, 0.42); color: #fff; }
.btn-ghost:hover { border-color: #fff; background: rgba(255, 255, 255, 0.08); }

/* ---------- sections ---------- */
.section { padding: 84px 0; }
.section-alt { background: var(--bg-alt); }
.section-title {
  margin: 0 0 18px;
  font-size: clamp(22px, 3.4vw, 30px);
  color: var(--navy);
  letter-spacing: 1px;
  position: relative;
  padding-left: 16px;
}
.section-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 5px;
  border-radius: 3px;
  background: var(--teal-bright);
}
.section-sub { margin: 0 0 40px; color: var(--muted); max-width: 720px; }

.about-text p { margin: 0 0 18px; color: #33465a; font-size: 16px; }
.about-text strong { color: var(--navy); }

.stats {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.stats li {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  box-shadow: var(--shadow);
}
.stat-num { display: block; font-size: 30px; font-weight: 700; color: var(--teal); letter-spacing: 1px; }
.stat-label { display: block; margin-top: 6px; font-size: 14px; color: var(--muted); }

/* ---------- product cards ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow);
  transition: transform .18s, border-color .18s, box-shadow .18s;
}
.card:hover {
  transform: translateY(-4px);
  border-color: var(--teal-bright);
  box-shadow: 0 16px 40px rgba(22, 163, 148, 0.16);
}
.card h3 {
  margin: 0 0 12px;
  font-size: 18px;
  color: var(--navy);
}
.card h3::after {
  content: "";
  display: block;
  width: 32px;
  height: 3px;
  margin-top: 10px;
  border-radius: 2px;
  background: var(--teal-bright);
}
.card p { margin: 0; font-size: 14.5px; color: var(--muted); }

/* ---------- tech tags ---------- */
.tags {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.tags li {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 10px 20px;
  font-size: 14.5px;
  color: var(--navy);
  box-shadow: 0 4px 14px rgba(15, 39, 64, 0.05);
}

/* ---------- contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.contact-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.contact-label { font-size: 13px; letter-spacing: 2px; color: var(--teal); text-transform: uppercase; }
.contact-value { font-size: 16px; color: var(--ink); word-break: break-word; }
a.contact-value:hover { color: var(--teal); }

/* ---------- footer ---------- */
.site-footer {
  background: var(--navy-deep);
  color: #a9bacb;
  padding: 40px 0;
  text-align: center;
}
.footer-inner p { margin: 4px 0; font-size: 14px; }
.footer-company { color: #e6eef6; font-size: 15px; letter-spacing: 1px; }
.footer-copy { color: #7d8fa3; font-size: 13px; }
.footer-beian a { color: #a9bacb; font-size: 13px; border-bottom: 1px solid transparent; }
.footer-beian a:hover { color: var(--teal-bright); border-color: var(--teal-bright); }

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .cards, .contact-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 680px) {
  .site-nav { display: none; }
  .hero { padding: 64px 0 72px; }
  .section { padding: 60px 0; }
  .stats, .cards, .contact-grid { grid-template-columns: 1fr; }
  .brand-text em { display: none; }
}