:root {
  --ink: #101a20;
  --muted: #5b6b7a;
  --line: #e3e8ed;
  --bg: #ffffff;
  --soft: #f5f8fa;
  --brand: #0e7c6b;
  --brand-dark: #0a5a4e;
  --radius: 12px;
  --wrap: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 400 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

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

img, svg { max-width: 100%; display: block; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.88);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s;
}
.nav.is-stuck { border-bottom-color: var(--line); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }

.brand { display: flex; align-items: center; gap: 10px; }
.brand-mark {
  width: 38px; height: 38px; border-radius: 10px;
  background: var(--brand); color: #fff;
  font-size: 15px; font-weight: 600; letter-spacing: .02em;
  display: grid; place-items: center;
}
.brand-text { font-size: 15px; font-weight: 500; letter-spacing: .01em; }

.nav-links { display: flex; gap: 32px; }
.nav-links a { font-size: 14px; color: var(--muted); transition: color .18s; }
.nav-links a:hover { color: var(--ink); }

.nav-toggle { display: none; background: none; border: 0; padding: 8px; cursor: pointer; }
.nav-toggle span { display: block; width: 20px; height: 1.5px; background: var(--ink); margin: 4px 0; }

/* ---------- hero ---------- */
.hero {
  padding: 96px 0 72px;
  background:
    radial-gradient(680px 320px at 88% -8%, rgba(14,124,107,.09), transparent 70%),
    linear-gradient(180deg, #ffffff 0%, var(--soft) 100%);
  border-bottom: 1px solid var(--line);
}
.eyebrow {
  margin: 0 0 16px; font-size: 13px; letter-spacing: .14em;
  text-transform: uppercase; color: var(--brand);
}
.hero h1 {
  margin: 0 0 24px; font-size: 52px; line-height: 1.2;
  font-weight: 500; letter-spacing: -.01em;
}
.lead { max-width: 620px; margin: 0 0 32px; font-size: 17px; color: var(--muted); }

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; height: 46px; padding: 0 26px;
  border-radius: 999px; font-size: 15px; font-weight: 500;
  transition: background .18s, color .18s, border-color .18s;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost { border: 1px solid var(--line); color: var(--ink); }
.btn-ghost:hover { border-color: var(--ink); }

.stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
  margin: 64px 0 0; padding: 28px 0 0; border-top: 1px solid var(--line);
}
.stats dt { font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.stats dd { margin: 0; font-size: 17px; font-weight: 500; }

/* ---------- sections ---------- */
.section { padding: 88px 0; }
.section-soft { background: var(--soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-head { margin-bottom: 44px; max-width: 680px; }
.section-head h2 { margin: 0; font-size: 32px; line-height: 1.35; font-weight: 500; letter-spacing: -.01em; }

.two-col { display: grid; grid-template-columns: 1.35fr 1fr; gap: 56px; align-items: start; }
.two-col p { margin: 0 0 20px; color: #33484f; }

.info-card {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 28px;
}
.info-card h3 { margin: 0 0 20px; font-size: 15px; font-weight: 500; }
.info-card dl { margin: 0; }
.info-card dl > div { display: grid; grid-template-columns: 108px 1fr; gap: 12px; padding: 12px 0; border-top: 1px solid var(--line); }
.info-card dl > div:first-child { border-top: 0; padding-top: 0; }
.info-card dt { font-size: 13px; color: var(--muted); }
.info-card dd { margin: 0; font-size: 14px; }

/* ---------- cards ---------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 32px 28px;
  transition: border-color .2s, transform .2s;
}
.card:hover { border-color: #cfd8de; transform: translateY(-2px); }
.card-icon { width: 44px; height: 44px; margin-bottom: 20px; }
.card-icon svg { width: 100%; height: 100%; fill: none; stroke: var(--brand); stroke-width: 1.8; stroke-linejoin: round; }
.card h3 { margin: 0 0 12px; font-size: 18px; font-weight: 500; }
.card p { margin: 0; font-size: 14px; color: var(--muted); line-height: 1.7; }

/* ---------- tech ---------- */
.tech-list { display: grid; gap: 28px; }
.tech-item {
  display: grid; grid-template-columns: 1.25fr 1fr; gap: 48px; align-items: center;
  padding: 36px; border: 1px solid var(--line); border-radius: var(--radius);
}
.tech-item:nth-child(even) { background: var(--bg); }
.tech-no { display: block; font-size: 13px; color: var(--brand); letter-spacing: .1em; margin-bottom: 12px; }
.tech-text h3 { margin: 0 0 14px; font-size: 20px; font-weight: 500; }
.tech-text p { margin: 0 0 20px; font-size: 14.5px; color: #33484f; line-height: 1.8; }
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; margin: 0; padding: 0; list-style: none; }
.tag-list li {
  font-size: 12.5px; color: var(--brand);
  background: rgba(14,124,107,.07); border-radius: 999px; padding: 5px 13px;
}
.tech-fig { background: var(--soft); border-radius: 10px; padding: 16px; }
.tech-fig svg { width: 100%; height: auto; }

/* ---------- contact ---------- */
.contact-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.contact-card { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.contact-card h3 { margin: 0 0 12px; font-size: 13px; font-weight: 500; color: var(--muted); }
.contact-card p { margin: 0; font-size: 15px; line-height: 1.7; }
.contact-card a { color: var(--brand); }
.contact-card a:hover { text-decoration: underline; }

/* ---------- footer ---------- */
.footer { padding: 56px 0 40px; border-top: 1px solid var(--line); background: var(--bg); }
.footer-inner { display: flex; justify-content: space-between; gap: 40px; flex-wrap: wrap; }
.footer-brand { margin: 0 0 8px; font-size: 16px; font-weight: 500; }
.footer-sub { margin: 0; font-size: 13.5px; color: var(--muted); }
.footer-meta { text-align: right; font-size: 13.5px; color: var(--muted); }
.footer-meta p { margin: 0 0 6px; }
.footer-meta a { color: var(--muted); }
.footer-meta a:hover { color: var(--ink); }
.footer-copy { color: #8d9aa5; }

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-in { opacity: 1; transform: none; }

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .hero h1 { font-size: 38px; }
  .two-col, .tech-item { grid-template-columns: 1fr; gap: 32px; }
  .cards, .contact-grid { grid-template-columns: 1fr 1fr; }
  .stats { grid-template-columns: 1fr 1fr; gap: 20px; }
  .section { padding: 64px 0; }
  .hero { padding: 64px 0 56px; }
  .section-head h2 { font-size: 26px; }
}

@media (max-width: 640px) {
  .nav-links {
    display: none; position: absolute; left: 0; right: 0; top: 68px;
    flex-direction: column; gap: 0; background: #fff;
    border-bottom: 1px solid var(--line); padding: 8px 24px 16px;
  }
  .nav-links.is-open { display: flex; }
  .nav-links a { padding: 12px 0; border-bottom: 1px solid var(--line); font-size: 15px; }
  .nav-links a:last-child { border-bottom: 0; }
  .nav-toggle { display: block; }
  .hero h1 { font-size: 30px; }
  .lead { font-size: 15.5px; }
  .cards, .contact-grid, .stats { grid-template-columns: 1fr; }
  .tech-item { padding: 24px 20px; }
  .footer-meta { text-align: left; }
}