:root {
  --bg: #0c1116;
  --bg-soft: #11181f;
  --surface: #ffffff;
  --ink: #0f1a24;
  --ink-soft: #4a5a68;
  --line: #e3e8ed;
  --brand: #1f6feb;
  --brand-dark: #1858c2;
  --accent: #f5a623;
  --ok: #16834f;
  --err: #d23f3f;
  --radius: 14px;
  --shadow: 0 10px 40px rgba(15, 26, 36, 0.08);
  --max: 1180px;
  --font: "Inter", system-ui, -apple-system, Segoe UI, sans-serif;
}
html[lang="zh"] body { font-family: "Noto Sans SC", var(--font); }

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--surface);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
.container { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; font-weight: 600; font-size: 15px; cursor: pointer;
  padding: 13px 26px; border-radius: 999px; border: 1.5px solid transparent;
  transition: transform .15s ease, background .2s ease, color .2s ease, box-shadow .2s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-sm { padding: 9px 18px; font-size: 14px; }
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 8px 20px rgba(31,111,235,.28); }
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--ink); }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.86); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 70px; gap: 24px; }
.brand, .footer-brand { display: inline-flex; align-items: center; gap: 12px; font-weight: 800; font-size: 21px; }
.brand-mark {
  width: 52px; height: 52px; object-fit: contain; border-radius: 6px; display: block;
}
.brand-mark-light { background: #fff; padding: 5px; border-radius: 10px; }
.site-header .brand-mark { width: 46px; height: 46px; }
.main-nav { display: flex; gap: 30px; margin-left: auto; }
.main-nav a { font-weight: 500; color: var(--ink-soft); font-size: 15px; transition: color .2s; }
.main-nav a:hover { color: var(--brand); }

.header-actions { display: flex; align-items: center; gap: 14px; }
.lang-switch { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.lang-btn {
  border: none; background: transparent; cursor: pointer; padding: 7px 13px;
  font-size: 13px; font-weight: 600; color: var(--ink-soft); transition: all .2s;
}
.lang-btn.is-active { background: var(--brand); color: #fff; }

.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 6px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--ink); border-radius: 2px; transition: .25s; }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; color: #fff; }
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(1100px 520px at 78% -10%, rgba(31,111,235,.55), transparent 60%),
    radial-gradient(900px 480px at 8% 110%, rgba(245,166,35,.30), transparent 55%),
    linear-gradient(160deg, #0c1116, #16222f 70%);
}
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 46px 46px; mask-image: radial-gradient(80% 80% at 60% 30%, #000, transparent);
}
.hero-inner { position: relative; z-index: 1; padding: 120px 24px 130px; max-width: 920px; }
.hero-eyebrow {
  text-transform: uppercase; letter-spacing: 3px; font-size: 13px; font-weight: 600;
  color: var(--accent); margin-bottom: 22px;
}
.hero-title { font-size: clamp(30px, 5vw, 52px); line-height: 1.15; font-weight: 800; letter-spacing: -.5px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 40px; }
.hero-cta .btn-ghost { color: #fff; border-color: rgba(255,255,255,.4); }
.hero-cta .btn-ghost:hover { border-color: #fff; background: rgba(255,255,255,.08); }

/* ---------- Sections ---------- */
.section { padding: 96px 0; }
.section-tag {
  display: inline-block; text-transform: uppercase; letter-spacing: 2px; font-size: 12px;
  font-weight: 700; color: var(--brand); background: rgba(31,111,235,.08);
  padding: 6px 14px; border-radius: 999px; margin-bottom: 18px;
}
.section-title { font-size: clamp(26px, 3.5vw, 38px); font-weight: 800; letter-spacing: -.5px; margin-bottom: 44px; }

/* About */
.about-grid { display: grid; grid-template-columns: 1fr 1.4fr; gap: 28px; }
.about-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 36px; box-shadow: var(--shadow);
}
.about-heading {
  font-size: 13px; text-transform: uppercase; letter-spacing: 2px; color: var(--ink-soft);
  margin-bottom: 14px; font-weight: 700;
}
.about-card p { font-size: 17px; color: var(--ink); }
.about-card p + p { margin-top: 16px; }
.about-note {
  font-size: 14.5px !important; color: var(--ink-soft) !important;
  border-left: 3px solid var(--accent); padding-left: 16px;
}

/* Areas */
.section-areas { background: var(--bg-soft); color: #eef3f7; }
.section-areas .section-tag { color: var(--accent); background: rgba(245,166,35,.12); }
.areas-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.area-card {
  background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.09);
  border-radius: var(--radius); padding: 28px; transition: transform .2s ease, border-color .2s ease, background .2s ease;
}
.area-card:hover { transform: translateY(-4px); border-color: rgba(31,111,235,.6); background: rgba(255,255,255,.06); }
.area-icon {
  display: grid; place-items: center; width: 46px; height: 46px; border-radius: 11px;
  background: linear-gradient(135deg, var(--brand), #3b8bff); color: #fff; margin-bottom: 18px; font-size: 22px;
}
.area-title { font-size: 19px; font-weight: 700; margin-bottom: 10px; }
.area-desc { font-size: 14.5px; color: #aebccb; }

/* Contact */
.section-contact { background: var(--surface); }
.contact-grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 56px; align-items: start; }
.contact-details { list-style: none; margin-top: 28px; display: grid; gap: 22px; }
.contact-details li { display: grid; gap: 5px; }
.contact-label { font-size: 12px; text-transform: uppercase; letter-spacing: 1.5px; color: var(--brand); font-weight: 700; }
.contact-details a { color: var(--ink); font-weight: 600; }
.contact-details a:hover { color: var(--brand); }

.contact-form {
  background: var(--bg-soft); color: #fff; border-radius: 18px; padding: 36px;
  box-shadow: var(--shadow);
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { display: flex; flex-direction: column; gap: 7px; margin-bottom: 18px; }
.field label { font-size: 13.5px; font-weight: 600; color: #c4d0db; }
.field input, .field textarea {
  font-family: inherit; font-size: 15px; color: #fff;
  background: rgba(255,255,255,.05); border: 1.5px solid rgba(255,255,255,.13);
  border-radius: 10px; padding: 12px 14px; transition: border-color .2s, background .2s;
  resize: vertical;
}
.field input:focus, .field textarea:focus {
  outline: none; border-color: var(--brand); background: rgba(31,111,235,.08);
}
.field input.invalid, .field textarea.invalid { border-color: var(--err); }
.error { color: #ff9a9a; font-size: 12.5px; min-height: 0; }
.form-actions { display: flex; gap: 12px; margin-top: 6px; }
.form-actions .btn-ghost { color: #fff; border-color: rgba(255,255,255,.3); }
.form-actions .btn-ghost:hover { border-color: #fff; }
.form-status { margin-top: 16px; font-size: 14px; font-weight: 600; min-height: 20px; }
.form-status.ok { color: #7ee2af; }
.form-status.err { color: #ff9a9a; }

/* Footer */
.site-footer { background: var(--bg); color: #aebccb; padding: 50px 0; }
.footer-inner { display: flex; flex-direction: column; gap: 14px; align-items: flex-start; }
.footer-brand { color: #fff; }
.footer-address { max-width: 560px; font-size: 14.5px; }
.footer-copy { font-size: 13px; color: #6c7d8d; }

/* Cookie banner */
.cookie-banner {
  position: fixed; left: 50%; bottom: 22px; transform: translateX(-50%);
  width: min(960px, calc(100% - 32px)); z-index: 80;
  display: flex; align-items: center; gap: 22px;
  background: #fff; border: 1px solid var(--line); border-radius: 14px;
  padding: 18px 22px; box-shadow: 0 16px 50px rgba(15,26,36,.22);
}
.cookie-banner p { font-size: 13.5px; color: var(--ink-soft); }
.cookie-banner[hidden] { display: none; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .areas-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 720px) {
  .main-nav {
    position: absolute; top: 70px; left: 0; right: 0; flex-direction: column; gap: 0;
    background: #fff; border-bottom: 1px solid var(--line); padding: 8px 0;
    transform: translateY(-12px); opacity: 0; pointer-events: none; transition: .22s;
  }
  .main-nav.open { transform: none; opacity: 1; pointer-events: auto; }
  .main-nav a { padding: 13px 24px; }
  .nav-toggle { display: flex; }
  .areas-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .hero-inner { padding: 84px 24px 90px; }
  .section { padding: 70px 0; }
  .cookie-banner { flex-direction: column; align-items: stretch; text-align: left; }
}