:root {
  --bg: #0b0f1a;
  --bg-alt: #0f1524;
  --card: #121a2e;
  --text: #e6eefc;
  --muted: #9bb0d4;
  --brand: #2d6cff;
  --brand-2: #00d4ff;
  --okx: #00b277;
  --border: #223054;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--text); font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif; line-height: 1.6; }
img { max-width: 100%; display: block; }
.a11y-hide { position: absolute; left: -9999px; }
.container { max-width: 1100px; margin: 0 auto; padding: 0 16px; }

.site-header { position: sticky; top: 0; z-index: 1000; background: rgba(11,15,26,0.85); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-weight: 700; letter-spacing: 0.5px; }
.nav a { color: var(--muted); margin: 0 12px; text-decoration: none; }
.nav a:hover { color: var(--text); }
.cta .btn { margin-left: 10px; }

.hero { background: radial-gradient(1000px 400px at 20% 0%, rgba(45,108,255,0.25), transparent), radial-gradient(800px 400px at 80% 0%, rgba(0,212,255,0.18), transparent), var(--bg-alt); padding: 72px 0 48px; border-bottom: 1px solid var(--border); }
.hero-inner { text-align: center; }
.hero h1 { font-size: 28px; margin: 0 0 12px; }
.subtitle { color: var(--muted); margin: 0 auto 20px; max-width: 760px; }
.trust { list-style: none; padding: 0; margin: 18px 0 0; color: var(--muted); }

.section { padding: 56px 0; }
.section.alt { background: #0c1323; }
.grid { display: grid; gap: 16px; }
.features-grid { grid-template-columns: repeat(4, 1fr); }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 18px; }
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0 0 8px; color: var(--muted); }

.btn { display: inline-block; padding: 10px 16px; border-radius: 10px; text-decoration: none; color: #fff; border: 1px solid transparent; transition: transform .05s ease, background .2s ease, color .2s ease; }
.btn:hover { transform: translateY(-1px); }
.btn.primary { background: linear-gradient(135deg, var(--brand), var(--brand-2)); }
.btn.secondary { background: #1b2a4a; border-color: #2a3a60; }
.btn.outline { background: transparent; border-color: #2a3a60; color: var(--text); }
.btn.lg { padding: 12px 18px; font-size: 16px; }
.btn.xl { padding: 14px 22px; font-size: 18px; }
.text-link { color: #8ab3ff; text-decoration: none; }
.text-link:hover { text-decoration: underline; }

.cta-row { display: flex; gap: 12px; flex-wrap: wrap; }
.footer-nav a { color: var(--muted); text-decoration: none; margin-right: 12px; }
.footer-nav a:hover { color: var(--text); }
.site-footer { border-top: 1px solid var(--border); background: var(--bg-alt); padding: 24px 0; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }

.bullets { color: var(--muted); }
.steps { padding-left: 18px; }
.faq details { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; margin-bottom: 10px; }
.faq summary { cursor: pointer; }

/* Mobile fixed bar */
.mobile-fixed-bar { position: fixed; left: 0; right: 0; bottom: 0; display: none; background: rgba(12,19,35,0.9); backdrop-filter: blur(8px); border-top: 1px solid var(--border); z-index: 1001; padding: 10px 12px; }
.mobile-fixed-bar .bar-btn { display: inline-block; flex: 1; margin: 0 6px; text-align: center; padding: 12px 0; border-radius: 10px; font-weight: 600; text-decoration: none; color: #fff; }
.mobile-fixed-bar .register { background: linear-gradient(135deg, var(--brand), var(--brand-2)); }
.mobile-fixed-bar .download { background: #1b2a4a; border: 1px solid #2a3a60; }

/* Responsive */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .header-inner { height: 56px; }
  .nav { display: none; }
  .hero { padding: 56px 0 32px; }
  .hero h1 { font-size: 22px; }
  .features-grid { grid-template-columns: 1fr; }
  .cta-row { justify-content: center; }
  body { padding-bottom: 72px; }
  .mobile-fixed-bar { display: flex; gap: 8px; }
}