:root {
  --bg: #070b17;
  --bg-soft: #0f1730;
  --card: rgba(255, 255, 255, 0.04);
  --text: #e9eefc;
  --muted: #9fb0d9;
  --line: rgba(126, 156, 255, 0.28);
  --brand: #7c8cff;
  --brand-2: #42d7ff;
}

/* Light theme (daytime readability) */
:root[data-theme="light"] {
  --bg: #f6f8ff;
  --bg-soft: #ffffff;
  --card: rgba(20, 28, 58, 0.04);
  --text: #0b1633;
  --muted: rgba(11, 22, 51, 0.62);
  --line: rgba(20, 28, 58, 0.14);
  --brand: #3753ff;
  --brand-2: #1fa8ff;
}

/* Follow system by default (user override via data-theme) */
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --bg: #f6f8ff;
    --bg-soft: #ffffff;
    --card: rgba(20, 28, 58, 0.04);
    --text: #0b1633;
    --muted: rgba(11, 22, 51, 0.62);
    --line: rgba(20, 28, 58, 0.14);
    --brand: #3753ff;
    --brand-2: #1fa8ff;
  }
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: radial-gradient(circle at 20% -10%, #21367d 0%, var(--bg) 45%);
  color: var(--text);
}

:root[data-theme="light"] body,
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) body {
    background: radial-gradient(circle at 20% -10%, rgba(55, 83, 255, 0.16) 0%, var(--bg) 45%);
  }
}
a { color: inherit; text-decoration: none; }
.container { width: min(1120px, 92%); margin: 0 auto; }
.nav {
  position: sticky; top: 0; z-index: 20;
  background: rgba(7, 11, 23, 0.88); backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
:root[data-theme="light"] .nav {
  background: rgba(255, 255, 255, 0.85);
}
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) .nav {
    background: rgba(255, 255, 255, 0.85);
  }
}

:root[data-theme="light"] .card {
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 14px 40px rgba(11, 22, 51, 0.06);
}
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) .card {
    background: rgba(255, 255, 255, 0.92);
    box-shadow: 0 14px 40px rgba(11, 22, 51, 0.06);
  }
}

:root[data-theme="light"] .footer {
  background: rgba(255, 255, 255, 0.92);
}
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) .footer {
    background: rgba(255, 255, 255, 0.92);
  }
}
.nav .inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 0; gap: 18px; }
.logo { font-weight: 700; letter-spacing: 0.3px; }
.links { display: flex; gap: 14px; flex-wrap: wrap; color: var(--muted); font-size: 14px; }
.links a:hover { color: var(--text); }
.lang { border: 1px solid var(--line); border-radius: 999px; padding: 6px 10px; font-size: 13px; color: var(--muted); }

.hero { padding: 64px 0 24px; }
.badge { display: inline-block; border: 1px solid var(--line); border-radius: 999px; padding: 6px 12px; color: var(--muted); font-size: 12px; }
h1 { font-size: clamp(30px, 4vw, 48px); margin: 16px 0 12px; line-height: 1.12; }
.lead { color: var(--muted); font-size: 17px; max-width: 760px; line-height: 1.6; }
.cta { margin-top: 20px; display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  border-radius: 12px; padding: 11px 16px; font-weight: 600; font-size: 14px;
  border: 1px solid var(--line);
}
.btn.primary {
  background: linear-gradient(90deg, var(--brand), var(--brand-2));
  border: none; color: #091329;
}

.section { padding: 26px 0; }
.section h2 { margin: 0 0 12px; font-size: 24px; }
.section p { color: var(--muted); margin: 0 0 14px; line-height: 1.7; }
.grid {
  display: grid; gap: 12px;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
}
.card {
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--card);
  padding: 14px;
}
.card h3 { margin: 0 0 8px; font-size: 16px; }
.card p { margin: 0; font-size: 13px; color: var(--muted); line-height: 1.55; }
.card:hover { border-color: rgba(124, 140, 255, 0.58); transform: translateY(-1px); }

.faq { margin-top: 10px; display: grid; gap: 10px; }
.faq-item { border: 1px solid var(--line); border-radius: 12px; padding: 12px; }
.faq-item h4 { margin: 0 0 6px; font-size: 14px; }
.faq-item p { margin: 0; font-size: 13px; color: var(--muted); }

.footer {
  margin-top: 40px; border-top: 1px solid var(--line); color: var(--muted);
  padding: 24px 0 34px; font-size: 13px;
}
.footer-links { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 10px; }

@media (max-width: 760px) {
  .nav .inner { align-items: flex-start; flex-direction: column; }
  h1 { font-size: clamp(26px, 8vw, 34px); line-height: 1.18; }
  .lead { font-size: 15px; line-height: 1.6; }
  .hero { padding: 42px 0 18px; }
  .cta { width: 100%; gap: 10px; }
  .btn { width: 100%; justify-content: center; }
  .grid { grid-template-columns: 1fr; }
  .section { padding: 22px 0; }
  .section h2 { font-size: 21px; }
}