:root {
  --bg: #f3f7f8;
  --ink: #14242b;
  --muted: #5b6f78;
  --line: rgba(20, 36, 43, 0.1);
  --brand: #0f6e64;
  --brand-deep: #0a4f48;
  --surface: #fff;
  --shadow: 0 18px 50px rgba(15, 40, 45, 0.08);
  --header-h: 72px;
  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  font-family: var(--sans);
  background:
    radial-gradient(900px 420px at 0% 0%, rgba(15, 110, 100, 0.08), transparent 60%),
    radial-gradient(700px 380px at 100% 10%, rgba(196, 92, 38, 0.05), transparent 55%),
    var(--bg);
  line-height: 1.7;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
.container { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  backdrop-filter: blur(14px);
  background: rgba(243, 247, 248, 0.88);
  border-bottom: 1px solid transparent;
  transition: border-color .25s ease, background .25s ease;
}
.site-header.is-scrolled {
  border-bottom-color: var(--line);
  background: rgba(255, 255, 255, 0.94);
}
.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 36px; height: 36px; border-radius: 10px;
  background: linear-gradient(145deg, var(--brand), #1aa392);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-text strong { font-family: var(--serif); font-size: 18px; letter-spacing: .04em; }
.brand-text small { color: var(--muted); font-size: 12px; }
.site-nav { display: flex; gap: 22px; }
.site-nav a {
  color: var(--muted); font-size: 14px; font-weight: 500; padding: 6px 0; position: relative;
}
.site-nav a::after {
  content: ""; position: absolute; left: 0; bottom: 0; width: 0; height: 2px;
  background: var(--brand); transition: width .25s ease;
}
.site-nav a:hover, .site-nav a.is-active { color: var(--brand-deep); }
.site-nav a:hover::after, .site-nav a.is-active::after { width: 100%; }
.nav-toggle {
  display: none; width: 42px; height: 42px; border: 1px solid var(--line);
  border-radius: 10px; background: var(--surface); cursor: pointer; padding: 10px;
}
.nav-toggle span { display: block; height: 2px; margin: 5px 0; background: var(--ink); }

.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  display: grid;
  align-items: end;
  color: #f7fffe;
  overflow: hidden;
}
.hero-media { position: absolute; inset: 0; }
.hero-media img {
  width: 100%; height: 100%; object-fit: cover;
  animation: heroZoom 18s ease-in-out infinite alternate;
}
.hero-shade {
  position: absolute; inset: 0;
  background:
    linear-gradient(90deg, rgba(8, 28, 30, .78) 12%, rgba(8, 28, 30, .4) 60%, rgba(8, 28, 30, .22)),
    linear-gradient(180deg, rgba(8, 28, 30, .12), rgba(8, 28, 30, .72));
}
.hero-content {
  position: relative; z-index: 1;
  width: min(760px, calc(100% - 40px));
  margin: 0 auto 0 max(20px, calc((100% - 1120px) / 2));
  padding: 72px 0 88px;
  animation: riseIn .85s ease both;
}
.hero-brand {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  letter-spacing: .06em;
}
.hero h1 {
  margin: 0 0 14px;
  font-family: var(--serif);
  font-size: clamp(28px, 4.2vw, 46px);
  line-height: 1.25;
}
.hero-lead { margin: 0 0 26px; color: rgba(247, 255, 254, .86); max-width: 34em; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 46px; padding: 0 20px; border-radius: 999px;
  font-size: 14px; font-weight: 700; transition: transform .2s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: #effaf7; color: var(--brand-deep); }
.btn-ghost { border: 1px solid rgba(255,255,255,.45); color: #fff; background: rgba(255,255,255,.06); }

.section { padding: 88px 0; }
.section-soft { background: linear-gradient(180deg, rgba(231, 241, 240, .7), transparent); }
.section-head { max-width: 720px; margin-bottom: 36px; }
.eyebrow {
  margin: 0 0 10px; color: var(--brand); font-size: 13px; font-weight: 700; letter-spacing: .12em;
}
h2 {
  margin: 0 0 12px; font-family: var(--serif); font-size: clamp(26px, 3vw, 36px); line-height: 1.3;
}
.section-desc, .about-only > p { margin: 0; color: var(--muted); max-width: 46em; }
.about-only { max-width: 760px; }
.plain-list { margin: 20px 0 0; padding: 0; list-style: none; }
.plain-list li { position: relative; padding-left: 18px; margin: 10px 0; }
.plain-list li::before {
  content: ""; position: absolute; left: 0; top: .65em; width: 8px; height: 8px;
  border-radius: 50%; background: var(--brand);
}

.feature-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
}
.feature-grid article { border-top: 2px solid var(--brand); padding-top: 14px; }
.feature-grid h3 { margin: 0 0 8px; font-family: var(--serif); font-size: 18px; }
.feature-grid p { margin: 0; color: var(--muted); font-size: 14px; }

.adv-list { display: grid; gap: 0; }
.adv-list article {
  display: grid; grid-template-columns: 72px 1fr; gap: 16px;
  padding: 24px 0; border-bottom: 1px solid var(--line);
}
.adv-list article:first-child { border-top: 1px solid var(--line); }
.adv-list span { font-family: var(--serif); font-size: 28px; color: var(--brand); line-height: 1; }
.adv-list h3 { margin: 0 0 6px; font-family: var(--serif); font-size: 20px; }
.adv-list p { margin: 0; color: var(--muted); }

.contact-box {
  display: grid; grid-template-columns: 1.1fr .9fr; gap: 28px;
  padding: 32px; background: var(--surface); border: 1px solid var(--line);
  border-radius: 12px; box-shadow: var(--shadow);
}
.contact-box dl { margin: 0; display: grid; gap: 14px; }
.contact-box dt { margin: 0 0 4px; color: var(--muted); font-size: 12px; letter-spacing: .08em; }
.contact-box dd { margin: 0; font-weight: 500; }
.contact-box a { color: var(--brand-deep); text-decoration: underline; text-underline-offset: 3px; }

.site-footer { padding: 36px 0 48px; border-top: 1px solid var(--line); background: #ecf3f2; }
.footer-inner { display: grid; grid-template-columns: 1.2fr 1fr 1fr; gap: 18px; }
.site-footer strong { font-family: var(--serif); font-size: 18px; }
.site-footer p { margin: 8px 0 0; color: var(--muted); font-size: 13px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 14px; }
.footer-links a, .footer-meta a { color: var(--muted); }
.footer-links a:hover, .footer-meta a:hover { color: var(--brand-deep); }
.beian-gongan a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.beian-gongan img {
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
}
.beian-gongan a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.beian-gongan img {
  width: 16px;
  height: 16px;
}

.back-top {
  position: fixed; right: 18px; bottom: 18px; width: 42px; height: 42px;
  border-radius: 50%; display: grid; place-items: center; background: var(--brand); color: #fff;
  opacity: 0; pointer-events: none; transform: translateY(8px); transition: .25s ease; z-index: 40;
}
.back-top.is-show { opacity: 1; pointer-events: auto; transform: none; }

.reveal { opacity: 0; transform: translateY(16px); transition: opacity .7s ease, transform .7s ease; }
.reveal.is-in { opacity: 1; transform: none; }

@keyframes heroZoom { from { transform: scale(1.02); } to { transform: scale(1.08); } }
@keyframes riseIn { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }

@media (max-width: 960px) {
  .feature-grid, .contact-box, .footer-inner { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .nav-toggle { display: inline-block; }
  .site-nav {
    display: none; position: absolute; top: var(--header-h); left: 20px; right: 20px;
    flex-direction: column; gap: 0; padding: 10px; background: #fff;
    border: 1px solid var(--line); border-radius: 12px; box-shadow: var(--shadow);
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 12px 10px; }
  .hero-content { margin-left: 20px; }
}
@media (max-width: 640px) {
  .feature-grid { grid-template-columns: 1fr; }
  .section { padding: 64px 0; }
}