:root {
  --bg: #f7f9fc;
  --surface: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --primary: #4f46e5;
  --primary-600: #4338ca;
  --ring: rgba(79,70,229,0.35);
  --radius: 16px;
  --shadow: 0 10px 25px rgba(0,0,0,0.06);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: 'Poppins', system-ui, -apple-system, Segoe UI, Roboto, 'Helvetica Neue', Arial, 'Noto Sans', 'Apple Color Emoji','Segoe UI Emoji', 'Segoe UI Symbol', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

img { max-width: 100%; height: auto; }

.container { max-width: 1100px; margin: 0 auto; padding: 0 16px; }
.narrow { max-width: 800px; }

/* Accessibility */
.skip-link {
  position: absolute; left: -999px; top: auto;
  width: 1px; height: 1px; overflow: hidden;
}
.skip-link:focus { left: 16px; top: 16px; width: auto; height: auto; padding: 8px 12px; background: #000; color: #fff; border-radius: 8px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: saturate(180%) blur(8px);
  background: rgba(255,255,255,0.75);
  border-bottom: 1px solid rgba(0,0,0,0.05);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 64px; }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: inherit; }
.brand-text { font-weight: 700; letter-spacing: 0.2px; }

.menu-toggle { display: none; border: none; background: transparent; font-size: 24px; }
.site-nav { display: flex; gap: 20px; }

.nav-link { text-decoration: none; color: var(--text); font-weight: 500; padding: 10px 12px; border-radius: 10px; }
.nav-link[aria-current="page"], .nav-link:hover { background: rgba(79,70,229,0.08); color: var(--primary); }

@media (max-width: 800px) {
  .menu-toggle { display: inline-flex; }
  .site-nav { 
    position: absolute; right: 16px; top: 64px; 
    background: var(--surface); box-shadow: var(--shadow); border-radius: var(--radius);
    padding: 10px; display: none; flex-direction: column; min-width: 220px;
  }
  .site-nav.open { display: flex; }
}

/* Hero */
.hero {
  background: radial-gradient(1200px 400px at 20% -10%, #dbeafe, transparent 60%),
              radial-gradient(1200px 400px at 80% -10%, #ede9fe, transparent 60%);
  padding: 64px 0 40px;
}
.hero-inner { text-align: center; }
.hero h1 { font-size: 44px; line-height: 1.15; margin: 0 0 12px; }
.lead { color: var(--muted); font-size: 18px; }

.cta-row { display: inline-flex; gap: 12px; margin-top: 16px; flex-wrap: wrap; }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 18px; border-radius: 12px; text-decoration: none; cursor: pointer; border: 1px solid transparent;
  font-weight: 600; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-600); }
.btn-secondary { background: #111827; color: #fff; }
.btn-ghost { background: transparent; border-color: rgba(0,0,0,0.12); color: var(--text); }
.btn-ghost:hover { background: rgba(0,0,0,0.04); }

/* Cards & Layouts */
.card { background: var(--surface); box-shadow: var(--shadow); border-radius: var(--radius); padding: 20px; }
.panel { background: #f3f4f6; border: 1px solid #e5e7eb; border-radius: var(--radius); padding: 16px; }
.tiny { font-size: 12px; }
.muted { color: var(--muted); }
.mt-4 { margin-top: 16px; }
.mt-6 { margin-top: 24px; }

.grid-3 { display: grid; grid-template-columns: repeat(3,1fr); gap: 16px; }
@media (max-width: 900px) { .grid-3 { grid-template-columns: 1fr; } }

.two-col { display: grid; grid-template-columns: 1.4fr 1fr; gap: 28px; align-items: center; }
@media (max-width: 900px) { .two-col { grid-template-columns: 1fr; } }

.featured { padding: 24px 0 48px; }
.illus { position: relative; }
.blob {
  position: absolute; inset: -20px -10px -20px -10px; border-radius: 40px;
  background: radial-gradient(500px 200px at 20% 10%, rgba(79,70,229,0.20), transparent 70%),
              radial-gradient(600px 220px at 80% 10%, rgba(99,102,241,0.20), transparent 70%);
  filter: blur(6px);
}
.hero-graphic { position: relative; border-radius: 20px; border: 1px solid rgba(0,0,0,0.06); }

.page-hero { padding: 36px 0; background: linear-gradient(180deg, #eef2ff, #fff 60%); border-bottom: 1px solid #e5e7eb; }
.page-hero h1 { margin: 0 0 8px; }

/* Footer */
.site-footer { margin-top: 48px; padding: 36px 0 16px; background: #0b1022; color: #d1d5db; }
.site-footer a { color: #e0e7ff; text-decoration: none; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 20px; }
.footer-title { margin: 0 0 8px; }
.footer-links { list-style: none; padding: 0; margin: 8px 0 0; }
.footer-links li { margin: 8px 0; }
.footer-bottom { margin-top: 20px; padding-top: 12px; border-top: 1px solid rgba(255,255,255,0.15); }
@media (max-width: 900px) { .footer-grid { grid-template-columns: 1fr; } }

/* Forms */
.form .form-row { display: grid; gap: 8px; margin: 12px 0; }
input, textarea {
  width: 100%; padding: 12px 14px; border-radius: 12px; border: 1px solid #d1d5db; background: #fff;
  outline: none; transition: box-shadow 0.2s ease, border-color 0.2s ease;
}
input:focus, textarea:focus { border-color: var(--primary); box-shadow: 0 0 0 4px var(--ring); }

/* Typography & Prose */
.prose h2 { margin-top: 8px; }
.prose h3 { margin-top: 24px; }
.pull { font-size: 18px; font-weight: 600; padding: 12px 16px; border-left: 4px solid var(--primary); background: #eef2ff; border-radius: 8px; }
.checklist { list-style: none; padding: 0; }
.checklist li::before { content: "✓"; margin-right: 8px; color: var(--primary); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }