:root {
  color-scheme: light dark;
  --bg-surface: #f4f6f8;
  --bg-section: #ffffff;
  --bg-dark: #0f172a;
  --fg-primary: #0b1120;
  --fg-secondary: #334155;
  --fg-muted: #475569;
  --accent: #2563eb;
  --accent-contrast: #f8fafc;
  --radius: 16px;
  --max-width: 960px;
  --shadow: 0 12px 40px rgba(15, 23, 42, 0.12);
  --transition: 200ms ease;
  font-family: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-surface: #020617;
    --bg-section: rgba(15, 23, 42, 0.72);
    --fg-primary: #e2e8f0;
    --fg-secondary: #cbd5f5;
    --fg-muted: #a5b4fc;
    --shadow: 0 12px 36px rgba(15, 23, 42, 0.45);
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg-surface);
  color: var(--fg-primary);
}

body {
  line-height: 1.6;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover,
a:focus {
  text-decoration: underline;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 16px;
  padding: 8px 16px;
  background: var(--accent);
  color: var(--accent-contrast);
  border-radius: 999px;
  transition: top var(--transition);
  z-index: 10;
}

.skip-link:focus {
  top: 16px;
}

.shell {
  width: min(100%, var(--max-width));
  margin: 0 auto;
  padding: 0 24px;
}

.site-header {
  background: var(--bg-dark);
  color: var(--accent-contrast);
  padding: 64px 0;
  position: relative;
  overflow: hidden;
}

.site-header::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top right, rgba(37, 99, 235, 0.35), transparent 55%),
    radial-gradient(circle at bottom left, rgba(59, 130, 246, 0.25), transparent 60%);
  pointer-events: none;
}

.branding {
  position: relative;
  z-index: 1;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 0.8rem;
  margin: 0 0 16px;
  color: rgba(248, 250, 252, 0.72);
}

.site-header h1 {
  margin: 0;
  font-size: clamp(2.5rem, 4vw, 3.25rem);
  letter-spacing: -0.03em;
}

.lede {
  margin-top: 16px;
  max-width: 640px;
  color: rgba(241, 245, 249, 0.82);
}

.copy-button {
  position: relative;
  z-index: 1;
  margin-top: 32px;
  padding: 12px 24px;
  border: 0;
  border-radius: 999px;
  background: var(--accent);
  color: var(--accent-contrast);
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}

.copy-button:hover,
.copy-button:focus {
  transform: translateY(-2px);
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.28);
}

.copy-button:active {
  transform: translateY(0);
}

.site-main {
  padding: 56px 0 88px;
}

.notice {
  margin-bottom: 32px;
}

.notice:last-of-type {
  margin-bottom: 0;
}

.notice .shell {
  background: var(--bg-section);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.notice h2 {
  margin-top: 0;
  margin-bottom: 16px;
  font-size: 1.5rem;
  color: var(--fg-secondary);
}

.notice p {
  margin: 0;
  color: var(--fg-muted);
}

.site-footer {
  background: var(--bg-dark);
  color: rgba(248, 250, 252, 0.72);
  padding: 32px 0;
}

.site-footer p {
  margin: 0;
  text-align: center;
}

@media (max-width: 640px) {
  .site-header {
    padding: 48px 0;
  }

  .copy-button {
    width: 100%;
  }

  .notice .shell {
    padding: 24px;
    border-radius: 12px;
  }
}