:root {
  --bg: #0f172a;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --brand: #2563eb;
  --brand-2: #0ea5e9;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: "Segoe UI", "PingFang SC", sans-serif; color: var(--text); background: #f4f7fb; }
a { color: var(--brand); text-decoration: none; }
.container { width: min(1100px, calc(100% - 32px)); margin: 0 auto; }
.site-header { background: var(--bg); color: #fff; }
.nav { display: flex; justify-content: space-between; align-items: center; min-height: 64px; gap: 16px; }
.nav a, .nav .credits, .link-btn { color: #e2e8f0; }
.logo { font-weight: 800; font-size: 20px; color: #fff !important; }
.nav nav { display: flex; gap: 16px; align-items: center; flex-wrap: wrap; }
.btn { background: linear-gradient(90deg, var(--brand), var(--brand-2)); color: #fff; border: 0; border-radius: 10px; padding: 10px 18px; cursor: pointer; font-weight: 600; display: inline-block; }
.btn-sm { padding: 6px 10px; font-size: 13px; }
.btn-secondary { background: #fff; color: #2563eb; border: 1px solid #2563eb; }
.btn:disabled, .btn-secondary:disabled { opacity: .55; cursor: not-allowed; }
.hero { background: radial-gradient(circle at top, #1e3a8a, #0f172a); color: #fff; padding: 72px 0; }
.hero h1 { font-size: 40px; margin: 0 0 12px; }
.hero-form { display: flex; gap: 8px; margin-top: 24px; }
.hero-form input, input[type="text"], input[type="password"], select { flex: 1; padding: 12px 14px; border-radius: 10px; border: 1px solid #dbe3ef; font-size: 16px; }
.module-card { display: flex; align-items: flex-start; gap: 8px; }
.module-card input[type="checkbox"] { flex: none; width: auto; padding: 0; margin-top: 4px; }
.cards-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; padding: 32px 0; }
.card, .tool-card, .auth-box { background: var(--card); border-radius: 16px; padding: 24px; box-shadow: 0 10px 30px rgba(15, 23, 42, .06); }
.auth-box { width: min(420px, calc(100% - 32px)); margin: 48px auto; display: grid; gap: 12px; }
.auth-box form, .auth-box label { display: grid; gap: 8px; }
.captcha-row { display: flex; gap: 8px; align-items: center; }
.error { color: #b91c1c; }
.site-footer { padding: 32px 0; color: var(--muted); }
.inline { display: inline; }
.link-btn { background: none; border: 0; cursor: pointer; }
.hidden { display: none !important; }
.crumbs { color: #64748b; margin: 16px 0; }
.article-page { padding: 32px 0 64px; }
.article-body { line-height: 1.8; }
.article-body h2 { margin-top: 28px; }
.article-body img, .cover { max-width: 100%; border-radius: 12px; }
.faq dt { font-weight: 700; margin-top: 12px; }
.embed-tool { margin: 24px 0; padding: 16px; background: #f8fafc; border-radius: 12px; }
@media (max-width: 800px) {
  .cards-3, .hero-form { grid-template-columns: 1fr; display: grid; }
  .hero h1 { font-size: 28px; }
}