:root {
  --bg: #0b1220;
  --bg-soft: #101a2e;
  --panel: #14203a;
  --border: #22314f;
  --text: #e8eef8;
  --text-dim: #9db0cc;
  --accent: #2dd4bf;
  --accent-2: #38bdf8;
  --warn: #fbbf24;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }

.container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* ---------- language toggle ---------- */
body.lang-en .lang-zh { display: none; }
body.lang-zh .lang-en { display: none; }

/* ---------- header ---------- */
header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(11, 18, 32, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; }
.brand .mark { width: 30px; height: 30px; }
.brand small { color: var(--text-dim); font-weight: 500; font-size: 12px; display: block; line-height: 1.2; }

nav.main-nav { display: flex; gap: 4px; align-items: center; }
nav.main-nav a {
  padding: 8px 14px; border-radius: 8px;
  color: var(--text-dim); font-size: 15px; transition: all .2s;
}
nav.main-nav a:hover { color: var(--text); background: var(--bg-soft); }
nav.main-nav a.active { color: var(--accent); background: rgba(45, 212, 191, 0.08); }

.lang-switch {
  border: 1px solid var(--border); background: var(--bg-soft); color: var(--text-dim);
  border-radius: 999px; padding: 6px 14px; font-size: 13px; cursor: pointer;
  transition: all .2s;
}
.lang-switch:hover { color: var(--accent); border-color: var(--accent); }

/* ---------- hero ---------- */
.hero {
  padding: 96px 0 80px;
  background:
    radial-gradient(ellipse 60% 50% at 75% 20%, rgba(45, 212, 191, 0.10), transparent),
    radial-gradient(ellipse 50% 40% at 20% 80%, rgba(56, 189, 248, 0.08), transparent);
}
.hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  color: var(--accent); font-size: 13px; letter-spacing: 2px;
  border: 1px solid rgba(45, 212, 191, 0.3); border-radius: 999px;
  padding: 6px 16px; margin-bottom: 24px;
  text-transform: uppercase;
}
h1 { font-size: 44px; line-height: 1.25; font-weight: 800; letter-spacing: -0.5px; }
h1 .grad {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero p.lead { margin-top: 20px; color: var(--text-dim); font-size: 17px; max-width: 520px; }
.hero-cta { margin-top: 36px; display: flex; gap: 16px; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px; border-radius: 10px; font-size: 15px; font-weight: 600;
  transition: all .2s; cursor: pointer; border: none;
}
.btn-primary { background: var(--accent); color: #052e2a; }
.btn-primary:hover { background: #5eead4; transform: translateY(-1px); }
.btn-ghost { border: 1px solid var(--border); color: var(--text); background: transparent; }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

.hero-chart {
  background: var(--panel); border: 1px solid var(--border); border-radius: 16px;
  padding: 24px; box-shadow: 0 20px 60px rgba(0,0,0,0.35);
}
.hero-chart .chart-title { font-size: 13px; color: var(--text-dim); margin-bottom: 16px; }

/* ---------- sections ---------- */
section { padding: 80px 0; }
.section-alt { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.section-head { max-width: 640px; margin-bottom: 48px; }
.section-head h2 { font-size: 32px; font-weight: 700; margin-top: 12px; }
.section-head p { color: var(--text-dim); margin-top: 12px; }
.kicker { color: var(--accent); font-size: 13px; letter-spacing: 2px; text-transform: uppercase; }

/* stats */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.stat {
  background: var(--panel); border: 1px solid var(--border); border-radius: 14px;
  padding: 28px 24px; text-align: center;
}
.stat .num { font-size: 34px; font-weight: 800; color: var(--accent); }
.stat .lbl { color: var(--text-dim); font-size: 14px; margin-top: 6px; }

/* cards */
.cards-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.cards-grid.two { grid-template-columns: repeat(2, 1fr); }
.card {
  background: var(--panel); border: 1px solid var(--border); border-radius: 14px;
  padding: 28px; transition: all .25s;
}
.card:hover { border-color: var(--accent); transform: translateY(-3px); }
.card .icon {
  width: 44px; height: 44px; border-radius: 10px;
  background: rgba(45, 212, 191, 0.1); color: var(--accent);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px; font-size: 20px;
}
.card h3 { font-size: 18px; margin-bottom: 10px; }
.card p { color: var(--text-dim); font-size: 14px; }
.card ul { margin-top: 14px; list-style: none; }
.card ul li {
  color: var(--text-dim); font-size: 14px; padding: 5px 0 5px 20px; position: relative;
}
.card ul li::before {
  content: ""; position: absolute; left: 0; top: 13px;
  width: 8px; height: 2px; background: var(--accent); border-radius: 1px;
}

/* process */
.process-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; counter-reset: step; }
.step {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 22px 18px; position: relative;
}
.step .no { color: var(--accent); font-weight: 800; font-size: 13px; letter-spacing: 1px; }
.step h4 { font-size: 15px; margin: 8px 0 6px; }
.step p { color: var(--text-dim); font-size: 13px; }

/* cases */
.case-tag {
  display: inline-block; font-size: 12px; color: var(--accent-2);
  border: 1px solid rgba(56, 189, 248, 0.35); border-radius: 999px;
  padding: 3px 12px; margin-bottom: 14px;
}
.case-metric {
  margin-top: 16px; padding-top: 16px; border-top: 1px dashed var(--border);
  display: flex; gap: 24px;
}
.case-metric div b { color: var(--accent); font-size: 20px; display: block; }
.case-metric div span { color: var(--text-dim); font-size: 12px; }

/* page hero (sub pages) */
.page-hero { padding: 72px 0 56px; border-bottom: 1px solid var(--border); background: var(--bg-soft); }
.page-hero h1 { font-size: 36px; }
.page-hero p { color: var(--text-dim); margin-top: 14px; max-width: 640px; }

/* about */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
.about-grid h2 { font-size: 26px; margin-bottom: 16px; }
.about-grid p { color: var(--text-dim); margin-bottom: 14px; }
.value-list { list-style: none; }
.value-list li {
  padding: 14px 0; border-bottom: 1px solid var(--border);
  display: flex; gap: 14px; align-items: baseline;
}
.value-list li b { color: var(--accent); white-space: nowrap; }
.value-list li span { color: var(--text-dim); }

/* contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.contact-item { display: flex; gap: 16px; padding: 20px 0; border-bottom: 1px solid var(--border); }
.contact-item .ci-icon { color: var(--accent); font-size: 20px; width: 32px; }
.contact-item b { display: block; font-size: 15px; }
.contact-item span { color: var(--text-dim); font-size: 14px; }

form.contact-form { display: grid; gap: 16px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
input, textarea, select {
  background: var(--bg-soft); border: 1px solid var(--border); border-radius: 10px;
  padding: 12px 16px; color: var(--text); font-size: 14px; font-family: inherit;
  width: 100%;
}
input:focus, textarea:focus, select:focus { outline: none; border-color: var(--accent); }
textarea { min-height: 120px; resize: vertical; }
label { font-size: 13px; color: var(--text-dim); display: block; margin-bottom: 6px; }

/* footer */
footer {
  border-top: 1px solid var(--border); padding: 48px 0 32px; margin-top: 40px;
  color: var(--text-dim); font-size: 14px;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 40px; margin-bottom: 36px; }
footer h5 { color: var(--text); font-size: 15px; margin-bottom: 14px; }
footer ul { list-style: none; }
footer ul li { padding: 4px 0; }
footer a:hover { color: var(--accent); }
.copyright { border-top: 1px solid var(--border); padding-top: 24px; font-size: 13px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; }

/* CTA band */
.cta-band {
  background: linear-gradient(120deg, rgba(45,212,191,0.12), rgba(56,189,248,0.12));
  border: 1px solid var(--border); border-radius: 20px;
  padding: 56px 48px; text-align: center;
}
.cta-band h2 { font-size: 28px; margin-bottom: 12px; }
.cta-band p { color: var(--text-dim); margin-bottom: 28px; }

/* chips (data coverage) */
.chips { display: flex; flex-wrap: wrap; gap: 10px; }
.chip {
  background: var(--panel); border: 1px solid var(--border); border-radius: 999px;
  padding: 10px 18px; font-size: 14px; color: var(--text-dim);
  transition: all .2s;
}
.chip:hover { border-color: var(--accent); color: var(--text); }
.chip b { color: var(--accent); font-weight: 600; }

/* legal disclaimer */
.footer-reg {
  margin-top: 24px;
  font-size: 12px; color: #7d8ea8; line-height: 1.7;
}
.footer-disclaimer {
  margin-top: 24px; padding-top: 16px;
  border-top: 1px dashed var(--border);
  font-size: 12px; color: #7d8ea8; line-height: 1.7;
}

/* placeholder note */
.ph-note { color: var(--warn); font-size: 12px; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero-grid, .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .cards-grid, .cards-grid.two { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .process-grid { grid-template-columns: repeat(2, 1fr); }
  h1 { font-size: 32px; }
  nav.main-nav { display: none; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
}

/* --- 数据门户入口 --- */
.main-nav .nav-portal {
  color: var(--accent, #2dd4bf);
  font-weight: 600;
  border: 1px solid var(--accent, #2dd4bf);
  border-radius: 999px;
  padding: 6px 14px;
  margin-left: 8px;
  transition: background .2s, color .2s;
}
.main-nav .nav-portal:hover { background: var(--accent, #2dd4bf); color: var(--bg, #0b1220); }