:root {
  --blue-900: #0a1a3a;
  --blue-800: #0d2a5c;
  --blue-700: #14377a;
  --blue-600: #1a4ba3;
  --blue-500: #2563eb;
  --blue-400: #3b82f6;
  --blue-100: #dbeafe;
  --blue-50: #eff6ff;
  --cyan: #22d3ee;
  --ink: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #ffffff;
  --bg-alt: #f6f9ff;
  --radius: 16px;
  --shadow: 0 20px 45px -20px rgba(10, 26, 58, 0.35);
  --font: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
.container { width: min(1160px, 92%); margin: 0 auto; }

/* ===== 导航 ===== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(255, 255, 255, 0.82);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  transition: box-shadow .3s ease;
}
.nav.scrolled { box-shadow: 0 8px 30px -18px rgba(10, 26, 58, 0.4); }
.nav-inner {
  width: min(1160px, 92%); margin: 0 auto; height: 68px;
  display: flex; align-items: center; justify-content: space-between; gap: 20px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.brand-mark {
  display: inline-flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 11px;
  background: linear-gradient(135deg, var(--blue-500), var(--cyan));
  color: #fff; font-size: 15px; letter-spacing: .5px; font-weight: 800;
}
.brand-text { font-size: 18px; color: var(--blue-900); }
.menu { display: flex; gap: 28px; }
.menu a { font-size: 14.5px; color: var(--muted); font-weight: 500; transition: color .2s; }
.menu a:hover { color: var(--blue-500); }
.nav-right { display: flex; align-items: center; gap: 14px; }
.lang-switch { display: flex; border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.lang-switch button {
  border: none; background: transparent; padding: 6px 12px; cursor: pointer;
  font-size: 13px; font-weight: 600; color: var(--muted); transition: all .2s;
}
.lang-switch button.active { background: var(--blue-500); color: #fff; }
.nav-cta {
  border: none; cursor: pointer; padding: 9px 20px; border-radius: 999px;
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600));
  color: #fff; font-weight: 600; font-size: 14px; font-family: inherit;
  transition: transform .15s, box-shadow .2s;
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 10px 24px -10px rgba(37, 99, 235, .7); }
.menu-toggle { display: none; border: none; background: none; font-size: 22px; cursor: pointer; color: var(--blue-900); }

/* ===== Hero ===== */
.hero { position: relative; padding: 160px 0 90px; background: linear-gradient(160deg, #0a1a3a 0%, #0d2a5c 45%, #14377a 100%); color: #fff; overflow: hidden; }
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(600px 400px at 85% 15%, rgba(34, 211, 238, .25), transparent 60%),
    radial-gradient(500px 400px at 10% 80%, rgba(37, 99, 235, .35), transparent 60%);
  opacity: .9;
}
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background-image: radial-gradient(rgba(255,255,255,.10) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: radial-gradient(700px 500px at 50% 40%, #000, transparent);
}
.hero-inner { position: relative; z-index: 1; }
.hero-kicker {
  display: inline-block; padding: 6px 16px; border-radius: 999px;
  background: rgba(34, 211, 238, .12); border: 1px solid rgba(34, 211, 238, .35);
  color: #a5f3fc; font-size: 13.5px; font-weight: 600; margin-bottom: 22px;
}
.hero h1 { font-size: clamp(34px, 5.4vw, 58px); line-height: 1.16; font-weight: 800; letter-spacing: -1px; }
.hero-sub { margin-top: 20px; font-size: 18px; color: rgba(255,255,255,.82); max-width: 620px; }
.hero-actions { margin-top: 34px; display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 13px 28px; border-radius: 12px; font-size: 15px; font-weight: 600;
  cursor: pointer; border: none; font-family: inherit; transition: transform .15s, box-shadow .2s;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: linear-gradient(135deg, var(--blue-500), var(--blue-600)); color: #fff; box-shadow: 0 14px 30px -12px rgba(37,99,235,.8); }
.btn-ghost { background: rgba(255,255,255,.08); color: #fff; border: 1px solid rgba(255,255,255,.25); }
.btn-ghost:hover { background: rgba(255,255,255,.16); }
.hero-stats { margin-top: 54px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; max-width: 820px; }
.stat { padding: 18px 20px; border-radius: 14px; background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.12); }
.stat strong { display: block; font-size: 30px; font-weight: 800; color: #fff; }
.stat span { font-size: 13px; color: rgba(255,255,255,.68); }

/* ===== Section 通用 ===== */
.section { padding: 90px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 54px; }
.section-head h2 { font-size: clamp(28px, 3.6vw, 40px); color: var(--blue-900); font-weight: 800; letter-spacing: -.5px; }
.section-head p { margin-top: 12px; font-size: 17px; color: var(--muted); }

/* ===== 卡片 ===== */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 28px; transition: transform .25s, box-shadow .25s;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: var(--blue-100); }
.card-icon { font-size: 34px; margin-bottom: 16px; }
.card h3 { font-size: 21px; color: var(--blue-900); margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; }
.card ul { margin-top: 18px; display: flex; flex-direction: column; gap: 9px; }
.card ul li { position: relative; padding-left: 22px; font-size: 14.5px; color: var(--ink); }
.card ul li::before { content: "✓"; position: absolute; left: 0; color: var(--blue-500); font-weight: 700; }

/* ===== 快照 ===== */
.snapshot-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.snap { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.snap h4 { font-size: 16px; color: var(--blue-600); margin-bottom: 8px; }
.snap p { color: var(--muted); font-size: 15px; }

/* ===== 热门线路 chips ===== */
.chips { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.chip {
  padding: 12px 22px; border-radius: 999px; background: #fff;
  border: 1px solid var(--line); font-size: 15px; font-weight: 600; color: var(--blue-800);
  transition: all .2s; cursor: default;
}
.chip:hover { border-color: var(--blue-400); color: var(--blue-500); transform: translateY(-2px); }

/* ===== 覆盖 ===== */
.coverage-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; max-width: 820px; margin: 0 auto; }
.cov-item {
  display: flex; align-items: center; gap: 12px; padding: 22px 24px; border-radius: 14px;
  background: #fff; border: 1px solid var(--line); font-size: 16px; font-weight: 600; color: var(--blue-900);
}
.cov-item em { margin-left: auto; font-style: normal; font-size: 12px; color: var(--blue-500); background: var(--blue-50); padding: 3px 10px; border-radius: 999px; }
.coverage-note { text-align: center; margin-top: 22px; font-size: 13px; color: var(--muted); }

/* ===== 优势 ===== */
.why-cards { grid-template-columns: repeat(4, 1fr); }
.why-cards .card h3 { font-size: 17px; }

/* ===== 流程 ===== */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.step { position: relative; background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 24px; }
.step-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; border-radius: 12px; font-weight: 800; font-size: 17px;
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600)); color: #fff; margin-bottom: 16px;
}
.step h4 { font-size: 17px; color: var(--blue-900); margin-bottom: 8px; }
.step p { color: var(--muted); font-size: 14.5px; }

/* ===== 联系 ===== */
.contact-inner { max-width: 640px; }
.contact-form { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 34px; box-shadow: var(--shadow); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.contact-form input, .contact-form select, .contact-form textarea {
  width: 100%; padding: 13px 15px; border: 1px solid var(--line); border-radius: 10px;
  font-size: 15px; font-family: inherit; color: var(--ink); background: var(--bg);
  margin-bottom: 14px; transition: border-color .2s, box-shadow .2s;
}
.contact-form input:focus, .contact-form select:focus, .contact-form textarea:focus {
  outline: none; border-color: var(--blue-400); box-shadow: 0 0 0 3px rgba(59, 130, 246, .15);
}
.contact-form textarea { resize: vertical; }
.contact-form .btn { width: 100%; }
.form-tip { margin-top: 12px; font-size: 14px; color: var(--blue-600); text-align: center; min-height: 20px; }

/* ===== 页脚 ===== */
.footer { background: var(--blue-900); color: rgba(255,255,255,.75); padding: 44px 0; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-size: 16px; font-weight: 600; color: #fff; margin-bottom: 10px; }
.footer-note { font-size: 13px; }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .menu { position: fixed; top: 68px; left: 0; right: 0; flex-direction: column; gap: 0;
    background: #fff; border-bottom: 1px solid var(--line); padding: 10px 5%; transform: translateY(-130%); transition: transform .3s; }
  .menu.open { transform: translateY(0); }
  .menu a { padding: 14px 0; border-bottom: 1px solid var(--line); }
  .menu-toggle { display: block; }
  .nav-cta { display: none; }
  .cards, .why-cards { grid-template-columns: 1fr; }
  .snapshot-grid { grid-template-columns: 1fr; }
  .coverage-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 520px) {
  .coverage-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .hero { padding: 130px 0 60px; }
}