:root {
  --blue: #0a4ea3;
  --blue-dark: #07366f;
  --blue-deep: #052a58;
  --blue-light: #1b6fd0;
  --fg: #2b2f36;
  --muted: #666d79;
  --line: #e5e8ee;
  --soft: #f5f6f8;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  color: var(--fg);
  background: #fff;
  line-height: 1.8;
}
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* language switch */
html[lang="en"] .zh { display: none !important; }
html[lang="zh"] .en { display: none !important; }

/* header */
header.site {
  position: sticky; top: 0; z-index: 50;
  background: linear-gradient(180deg, #f1f2f4, #e3e5e8);
  border-bottom: 1px solid #d9dce1;
}
header.site .wrap { display: flex; align-items: center; justify-content: space-between; height: 80px; }
.logo { display: flex; align-items: center; gap: 10px; color: var(--blue-dark); font-weight: 800; font-size: 24px; letter-spacing: 1px; }
.logo:hover { text-decoration: none; }
.logo svg { width: 40px; height: 40px; }
.logo img { height: 34px; width: auto; display: block; }
.logo small { display: block; font-size: 10px; font-weight: 600; letter-spacing: 2px; color: var(--muted); margin-top: -4px; }
nav.main { display: flex; align-items: center; gap: 36px; }
nav.main a { color: #22262d; font-weight: 700; font-size: 16px; padding: 6px 0; border-bottom: 2px solid transparent; }
nav.main a:hover, nav.main a.active { color: var(--blue); border-bottom-color: var(--blue); text-decoration: none; }
.lang-btn {
  border: 1px solid #bfc4cc; background: #fff; color: #22262d;
  padding: 5px 12px; border-radius: 4px; cursor: pointer; font-size: 14px;
}
.lang-btn:hover { background: var(--soft); }
.menu-btn { display: none; background: none; border: 0; font-size: 26px; cursor: pointer; color: #22262d; }

/* banner */
.banner {
  position: relative; overflow: hidden; color: #fff; text-align: center;
  background:
    radial-gradient(circle at 20% 30%, rgba(255,255,255,.10) 0, transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(255,255,255,.08) 0, transparent 45%),
    linear-gradient(135deg, #061f45 0%, #0a4ea3 55%, #1b6fd0 100%);
}
.banner::before {
  content: ""; position: absolute; inset: 0; opacity: .35;
  background-image: radial-gradient(rgba(255,255,255,.55) 1.2px, transparent 1.4px);
  background-size: 26px 26px;
  -webkit-mask-image: linear-gradient(180deg, transparent, #000 40%, transparent);
          mask-image: linear-gradient(180deg, transparent, #000 40%, transparent);
}
.banner .wrap { position: relative; }
.banner.inner { padding: 120px 0 110px; }
.banner.inner h1 { font-size: 48px; margin: 0 0 6px; letter-spacing: 2px; }
.banner.inner .sub { font-size: 20px; opacity: .92; }
.banner.home {
  padding: 52px 0 200px; min-height: 470px;
  background:
    linear-gradient(180deg, rgba(4,26,64,.80) 0%, rgba(4,26,64,.50) 45%, rgba(4,26,64,0) 75%),
    url('hero.jpg') center bottom / cover no-repeat,
    #0a2a5c;
}
.banner.home::before { display: none; }
.banner.home h1 { font-size: 40px; line-height: 1.3; margin: 0 0 14px; text-shadow: 0 2px 14px rgba(0,0,0,.45); }
.banner.home p { font-size: 18px; max-width: 680px; margin: 0 auto; opacity: .96; text-shadow: 0 1px 10px rgba(0,0,0,.5); }
.btn {
  display: inline-block; padding: 12px 30px; border-radius: 4px; font-size: 16px; font-weight: 600;
  background: #fff; color: var(--blue-dark); margin: 0 8px; border: 1px solid #fff;
}
.btn:hover { text-decoration: none; background: #e9f0fb; }
.btn.ghost { background: transparent; color: #fff; }
.btn.ghost:hover { background: rgba(255,255,255,.14); }

/* breadcrumb */
.crumb { background: var(--soft); border-bottom: 1px solid var(--line); font-size: 14px; color: var(--muted); }
.crumb .wrap { height: 74px; display: flex; align-items: center; justify-content: flex-end; }
.crumb a { color: var(--fg); }

/* sections */
section.block { padding: 64px 0; }
section.alt { background: var(--soft); }
.sec-title { text-align: center; margin-bottom: 40px; }
.sec-title h2 { font-size: 30px; margin: 0; font-weight: 600; }
.sec-title .line { width: 56px; height: 3px; background: var(--blue); margin: 14px auto 0; }
.sec-title p { color: var(--muted); margin: 14px 0 0; }
p { margin: 0 0 16px; }
.lead { text-indent: 2em; }
html[lang="en"] .lead { text-indent: 0; }
.text-block { max-width: 920px; margin: 0 auto; border-top: 1px solid var(--line); padding-top: 28px; color: #4a505b; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.card { background: #fff; border: 1px solid var(--line); border-radius: 6px; padding: 30px 26px; border-top: 3px solid var(--blue); }
.card h3 { margin: 0 0 10px; font-size: 19px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.ico { width: 44px; height: 44px; margin-bottom: 14px; color: var(--blue); }

dl.facts { display: grid; grid-template-columns: 200px 1fr; gap: 12px 24px; max-width: 920px; margin: 28px auto 0; padding: 22px 26px; background: #fff; border: 1px solid var(--line); border-radius: 6px; }
dl.facts dt { color: var(--muted); }
dl.facts dd { margin: 0; }

/* contact */
.contact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; margin-bottom: 8px; }
.info { background: #fff; border: 1px solid var(--line); border-radius: 6px; padding: 26px; text-align: center; }
.info h3 { margin: 10px 0 6px; font-size: 17px; }
.info p { margin: 0; color: var(--muted); font-size: 15px; word-break: break-word; }

form.msg { max-width: 1000px; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
form.msg input, form.msg textarea {
  width: 100%; border: 1px solid var(--line); background: #fafbfc; padding: 13px 16px; font: inherit; font-size: 15px; border-radius: 3px;
}
form.msg input:focus, form.msg textarea:focus { outline: 2px solid rgba(10,78,163,.35); background: #fff; }
form.msg .full { grid-column: 1 / -1; }
form.msg textarea { min-height: 130px; resize: vertical; }
form.msg button {
  grid-column: 1 / -1; background: var(--blue); color: #fff; border: 0; padding: 14px; font-size: 15px; cursor: pointer; border-radius: 3px;
}
form.msg button:hover { background: var(--blue-dark); }
form.msg button[disabled] { opacity: .6; cursor: default; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; opacity: 0; }
#formStatus { grid-column: 1 / -1; text-align: center; font-size: 15px; min-height: 22px; }
#formStatus.ok { color: #1a7f37; }
#formStatus.err { color: #b42318; }

/* footer */
.wave { display: block; width: 100%; height: 90px; margin-bottom: -1px; }
footer.site { background: var(--blue); color: #fff; }
footer.site .top { padding: 44px 0 36px; display: grid; grid-template-columns: 1.6fr 1fr 1fr; gap: 32px; }
footer.site h4 { margin: 0 0 14px; font-size: 18px; }
footer.site a { color: #fff; opacity: .88; }
footer.site a:hover { opacity: 1; }
footer.site .col a { display: block; margin-bottom: 6px; }
footer.site .contact p { margin: 0 0 6px; opacity: .92; }
footer.site .logo { color: #fff; margin-bottom: 18px; }
footer.site .logo small { color: rgba(255,255,255,.7); }
footer.site .copy { background: var(--blue-deep); text-align: center; padding: 16px 20px; font-size: 14px; color: rgba(255,255,255,.7); }

/* floating side buttons */
.side { position: fixed; right: 0; top: 46%; z-index: 60; display: flex; flex-direction: column; }
.side a, .side button {
  width: 64px; padding: 12px 0 10px; background: var(--blue); color: #fff; border: 0; border-bottom: 1px solid rgba(255,255,255,.25);
  text-align: center; font-size: 12px; cursor: pointer; line-height: 1.3;
}
.side a:hover, .side button:hover { background: var(--blue-dark); text-decoration: none; }
.side svg { width: 24px; height: 24px; display: block; margin: 0 auto 4px; }
#toTop { display: none; }

/* legal pages */
.doc { padding: 56px 0 72px; max-width: 880px; margin: 0 auto; }
.doc h2 { font-size: 20px; margin: 30px 0 8px; }
.doc ul { padding-left: 22px; margin: 0 0 14px; }
.doc .updated { color: var(--muted); font-size: 14px; }

@media (max-width: 860px) {
  .menu-btn { display: block; }
  nav.main {
    display: none; position: absolute; top: 80px; left: 0; right: 0; background: #f1f2f4;
    flex-direction: column; align-items: flex-start; gap: 0; padding: 8px 24px 16px; border-bottom: 1px solid #d9dce1;
  }
  nav.main.open { display: flex; }
  nav.main a { padding: 12px 0; width: 100%; border-bottom: 1px solid var(--line); }
  .banner.inner { padding: 80px 0 70px; }
  .banner.inner h1 { font-size: 34px; }
  .banner.home {
    padding: 52px 0 150px; min-height: 440px;
    background:
      linear-gradient(180deg, #0a2a5c 0%, #0a2a5c 62%, rgba(10,42,92,0) 82%),
      url('hero.jpg') center bottom / 155% auto no-repeat,
      #0a2a5c;
  }
  .banner.home h1 { font-size: 30px; }
  .banner.home p { font-size: 16px; padding: 0 8px; }
  .logo img { height: 26px; max-width: 70vw; }
  .banner.home h1 { font-size: 32px; }
  .crumb .wrap { height: 54px; }
  dl.facts { grid-template-columns: 1fr; gap: 2px; }
  dl.facts dd { margin-bottom: 12px; }
  form.msg { grid-template-columns: 1fr; }
  footer.site .top { grid-template-columns: 1fr; }
  .side a, .side button { width: 52px; }
}