:root {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-soft: #f1f5f9;
  --text: #0f172a;
  --text-muted: #475569;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --border: #e2e8f0;
}

html {
  font-size: 16px;
  min-height: 100%;
}

body {
  color: var(--text);
  background: radial-gradient(circle at top right, #e0ecff 0%, var(--bg) 35%);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main {
  flex: 1;
}

.site-nav {
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.navbar-brand {
  letter-spacing: 0.2px;
  color: var(--text);
}

.nav-link {
  color: var(--text-muted);
  font-weight: 500;
  border-radius: 999px;
  padding: 0.45rem 0.9rem;
}

.nav-link:hover,
.nav-link:focus {
  color: var(--text);
  background: var(--surface-soft);
}

.skip-link {
  position: absolute;
  left: -9999px;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
  background: #111827;
  color: #fff;
  padding: 0.5rem 0.75rem;
  border-radius: 0.4rem;
  z-index: 1000;
}

.hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 55%, #2563eb 100%);
  color: #fff;
  border-radius: 1rem;
  padding: 3rem 2rem;
  box-shadow: 0 24px 44px rgba(15, 23, 42, 0.18);
}

.section-title {
  font-size: 2rem;
  margin-bottom: 0.75rem;
}

.lead-copy {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 70ch;
}

.hero .lead-copy {
  color: rgba(255, 255, 255, 0.88);
}

.surface-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.9rem;
  padding: 1.5rem;
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.06);
}

.btn-primary {
  background-color: var(--primary);
  border-color: var(--primary);
}

.btn-primary:hover,
.btn-primary:focus {
  background-color: var(--primary-dark);
  border-color: var(--primary-dark);
}

.footer {
  border-top: 1px solid var(--border);
  margin-top: 2rem;
  padding: 1.2rem 0;
  background: rgba(255, 255, 255, 0.8);
}

.btn:focus,
.btn:active:focus,
.btn-link.nav-link:focus,
.form-control:focus,
.form-check-input:focus {
  box-shadow: 0 0 0 0.2rem rgba(37, 99, 235, 0.25);
}