:root {
  color-scheme: light;
  --text: #0f172a;
  --text-secondary: #334155;
  --muted: #64748b;
  --bg: #f1f5f9;
  --bg-accent: #e2e8f0;
  --surface: #ffffff;
  --border: #e2e8f0;
  --link: #1d4ed8;
  --link-hover: #1e40af;
  --brand: #1e3a8a;
  --brand-light: #2563eb;
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.08), 0 8px 24px rgba(15, 23, 42, 0.06);
  --radius: 12px;
  --radius-lg: 16px;
  --max-width: 44rem;
  --header-height: 4rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --text: #f8fafc;
    --text-secondary: #cbd5e1;
    --muted: #94a3b8;
    --bg: #0f172a;
    --bg-accent: #1e293b;
    --surface: #1e293b;
    --border: #334155;
    --link: #60a5fa;
    --link-hover: #93c5fd;
    --brand: #dbeafe;
    --brand-light: #60a5fa;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 8px 24px rgba(0, 0, 0, 0.25);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text-secondary);
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(37, 99, 235, 0.12), transparent),
    linear-gradient(180deg, var(--bg-accent) 0%, var(--bg) 24rem);
}

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--link-hover);
  text-decoration: underline;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

@media (prefers-color-scheme: dark) {
  .site-header {
    background: rgba(15, 23, 42, 0.9);
  }
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  max-width: 56rem;
  margin: 0 auto;
  padding: 0 1.5rem;
  min-height: var(--header-height);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--brand);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.brand:hover {
  text-decoration: none;
  color: var(--brand-light);
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: 8px;
  background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 100%);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.site-header nav {
  display: flex;
  gap: 0.375rem;
}

.site-header nav a {
  padding: 0.5rem 0.875rem;
  border-radius: 999px;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
}

.site-header nav a:hover {
  color: var(--text);
  background: var(--bg-accent);
  text-decoration: none;
}

.site-header nav a[aria-current="page"] {
  color: #fff;
  background: var(--brand-light);
  font-weight: 600;
}

.site-header nav a[aria-current="page"]:hover {
  color: #fff;
  background: #1d4ed8;
}

/* Layout */
.page-shell {
  flex: 1;
  width: 100%;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem 1.5rem 2rem;
}

.container-wide {
  max-width: 56rem;
}

/* Hero (home) */
.hero {
  margin-bottom: 2rem;
}

.hero-eyebrow {
  display: inline-block;
  margin: 0 0 0.75rem;
  padding: 0.25rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--brand-light);
  background: rgba(37, 99, 235, 0.1);
  border-radius: 999px;
}

h1 {
  margin: 0 0 1rem;
  font-size: clamp(1.875rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--text);
}

.lead {
  margin: 0;
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--text-secondary);
  max-width: 38rem;
}

/* Cards */
.card-grid {
  display: grid;
  gap: 1rem;
  margin-top: 2rem;
}

@media (min-width: 36rem) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.card {
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.card h2 {
  margin: 0 0 0.75rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}

.card p {
  margin: 0;
}

.card ul {
  margin: 0;
  padding-left: 1.125rem;
}

.card li + li {
  margin-top: 0.375rem;
}

.card a {
  font-weight: 500;
}

.content-card {
  padding: 2rem 1.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.content-card > :first-child {
  margin-top: 0;
}

.content-card h2 {
  margin: 2rem 0 0.75rem;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text);
  padding-top: 0.25rem;
  border-top: 1px solid var(--border);
}

.content-card h2:first-of-type {
  margin-top: 1.5rem;
  border-top: none;
  padding-top: 0;
}

.content-card p {
  margin: 0 0 1rem;
}

.content-card ul {
  margin: 0 0 1rem;
  padding-left: 1.25rem;
}

.content-card li + li {
  margin-top: 0.5rem;
}

.content-card li {
  padding-left: 0.25rem;
}

.page-intro {
  margin: 0 0 0;
  font-size: 1.0625rem;
}

.last-updated {
  margin: 0.5rem 0 1.5rem;
  color: var(--muted);
  font-size: 0.875rem;
}

.disclaimer-banner {
  margin-top: 2rem;
  padding: 1rem 1.25rem;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  background: rgba(37, 99, 235, 0.06);
  border: 1px solid rgba(37, 99, 235, 0.15);
  border-radius: var(--radius);
}

@media (prefers-color-scheme: dark) {
  .disclaimer-banner {
    background: rgba(37, 99, 235, 0.12);
    border-color: rgba(96, 165, 250, 0.2);
  }
}

/* Footer */
.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.5);
}

@media (prefers-color-scheme: dark) {
  .site-footer {
    background: rgba(15, 23, 42, 0.5);
  }
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  max-width: 56rem;
  margin: 0 auto;
  padding: 1.5rem;
  font-size: 0.875rem;
  color: var(--muted);
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}

.footer-links a {
  color: var(--muted);
  font-weight: 500;
}

.footer-links a:hover {
  color: var(--link);
}