:root {
  --bg: #060b18;
  --bg-soft: #0b1426;
  --card: #101c33;
  --line: rgba(120, 200, 255, 0.14);
  --fg: #eaf2ff;
  --muted: #97a9c4;
  --brand: #17c9ff;
  --brand-2: #2f6bff;
  --radius: 16px;
  --wrap: 1160px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
.link { color: var(--brand); text-decoration: underline; text-underline-offset: 3px; }
.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 20px; }
.muted { color: var(--muted); font-size: 14px; }

/* header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(6, 11, 24, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; gap: 24px; height: 68px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 19px; letter-spacing: 0.2px; }
.logo img { width: 34px; height: 34px; }
.nav { display: flex; gap: 22px; flex: 1; font-size: 15px; color: var(--muted); flex-wrap: wrap; }
.nav a:hover, .nav a.active { color: var(--fg); }
.header-actions { display: flex; align-items: center; gap: 14px; }
.lang { font-size: 14px; color: var(--muted); border: 1px solid var(--line); border-radius: 999px; padding: 4px 12px; }
.lang:hover { color: var(--fg); }

/* buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 20px; border-radius: 999px; font-weight: 600; font-size: 15px;
  border: 1px solid transparent; transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.2s ease;
  white-space: nowrap;
}
.btn-primary { background: linear-gradient(120deg, var(--brand), var(--brand-2)); color: #01111f; box-shadow: 0 10px 30px rgba(23, 201, 255, 0.25); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 14px 34px rgba(23, 201, 255, 0.35); }
.btn-ghost { border-color: var(--line); color: var(--fg); }
.btn-ghost:hover { background: rgba(120, 200, 255, 0.08); }
.btn-lg { padding: 13px 28px; font-size: 16px; }

/* hero */
.hero {
  padding: 84px 0 64px;
  background:
    radial-gradient(900px 420px at 12% -10%, rgba(23, 201, 255, 0.22), transparent 60%),
    radial-gradient(700px 400px at 90% 0%, rgba(47, 107, 255, 0.22), transparent 60%),
    var(--bg);
  border-bottom: 1px solid var(--line);
}
.hero-inner { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 48px; align-items: center; }
.hero-copy { max-width: 640px; }
.eyebrow { color: var(--brand); font-size: 14px; letter-spacing: 2px; margin: 0 0 12px; text-transform: uppercase; }
h1 { font-size: clamp(30px, 4.4vw, 50px); line-height: 1.18; margin: 0 0 16px; letter-spacing: -0.5px; }
.lead { color: var(--muted); font-size: 17px; margin: 0 0 26px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-media img { border-radius: 22px; border: 1px solid var(--line); box-shadow: 0 30px 70px rgba(0, 0, 0, 0.5); }
.stats { list-style: none; display: flex; gap: 34px; padding: 34px 0 0; margin: 0; flex-wrap: wrap; }
.stats strong { display: block; font-size: 26px; color: var(--brand); }
.stats span { font-size: 14px; color: var(--muted); }

/* sections */
.section { padding: 72px 0; border-bottom: 1px solid var(--line); }
.section.alt { background: var(--bg-soft); }
.section h2 { font-size: clamp(24px, 3vw, 34px); margin: 0 0 12px; }
.section .lead { max-width: 760px; }

.grid { display: grid; gap: 20px; margin-top: 30px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; transition: transform 0.18s ease, border-color 0.18s ease;
}
.card:hover { transform: translateY(-3px); border-color: rgba(23, 201, 255, 0.4); }
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

.media-card img { border-radius: 22px; border: 1px solid var(--line); margin-top: 28px; }

.plan {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; display: flex; flex-direction: column; gap: 14px;
}
.plan h3 { margin: 0; font-size: 22px; }
.plan p { margin: 0; color: var(--muted); font-size: 15px; }
.plan ul { margin: 0; padding-left: 18px; color: var(--muted); font-size: 15px; }
.plan .btn { margin-top: auto; align-self: flex-start; }

.faq { border: 1px solid var(--line); border-radius: 12px; padding: 14px 18px; margin-top: 12px; background: var(--card); }
.faq summary { cursor: pointer; font-weight: 600; }
.faq p { color: var(--muted); margin: 10px 0 0; }

.section h3 { margin: 26px 0 6px; font-size: 18px; }
.section p { color: var(--muted); }

.cta-band {
  padding: 68px 0; text-align: center;
  background: linear-gradient(120deg, rgba(23, 201, 255, 0.16), rgba(47, 107, 255, 0.16));
  border-bottom: 1px solid var(--line);
}
.cta-band h2 { margin: 0 0 10px; font-size: clamp(22px, 3vw, 32px); }
.cta-band p { color: var(--muted); margin: 0 0 24px; }

/* footer */
.site-footer { background: #04080f; padding: 56px 0 26px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 32px; }
.footer-brand p { color: var(--muted); font-size: 14px; margin: 14px 0 0; max-width: 320px; }
.footer-col h3 { font-size: 15px; margin: 0 0 12px; }
.footer-col a { display: block; color: var(--muted); font-size: 14px; padding: 4px 0; }
.footer-col a:hover { color: var(--brand); }
.footer-bottom { border-top: 1px solid var(--line); margin-top: 34px; padding-top: 20px; color: var(--muted); font-size: 13px; }

@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; }
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .nav { display: none; }
  .hero { padding: 56px 0 44px; }
}