:root {
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-text: #1e293b;
  --color-muted: #64748b;
  --color-accent: #2f5da8;
  --color-accent-hover: #244a87;
  --color-border: #e2e8f0;
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;
  --max-width: 720px;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.08);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  display: flex;
  flex-direction: column;
}

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

a:hover {
  text-decoration: underline;
}

.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 1.5rem;
}

.site-header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.site-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.02em;
}

.site-logo:hover {
  text-decoration: none;
  color: var(--color-accent-hover);
}

.site-nav {
  display: flex;
  gap: 1.25rem;
  font-size: 0.9375rem;
}

.site-nav a {
  color: var(--color-muted);
}

.site-nav a:hover {
  color: var(--color-accent);
}

main {
  flex: 1;
  padding: 2.5rem 1.5rem 3rem;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.hero {
  text-align: center;
  padding: 2rem 0 1rem;
}

.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(2rem, 5vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--color-text);
}

.hero .tagline {
  margin: 0;
  font-size: clamp(1.0625rem, 2.5vw, 1.25rem);
  color: var(--color-muted);
  max-width: 28ch;
  margin-inline: auto;
}

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

.card h2 {
  margin: 0 0 0.75rem;
  font-size: 1.25rem;
  font-weight: 600;
}

.card p {
  margin: 0 0 1rem;
  color: var(--color-muted);
}

.card p:last-child {
  margin-bottom: 0;
}

.page-title {
  margin: 0 0 0.5rem;
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.page-meta {
  margin: 0 0 2rem;
  font-size: 0.875rem;
  color: var(--color-muted);
}

.prose h2 {
  margin: 2rem 0 0.75rem;
  font-size: 1.125rem;
  font-weight: 600;
}

.prose h2:first-child {
  margin-top: 0;
}

.prose p,
.prose li {
  color: var(--color-muted);
}

.prose ul {
  padding-left: 1.25rem;
}

.prose li + li {
  margin-top: 0.35rem;
}

.notice {
  background: #eff6ff;
  border: 1px solid #d6e7ff;
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  font-size: 0.9375rem;
  color: var(--color-text);
}

.notice strong {
  color: var(--color-accent);
}

.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 1.5rem;
  text-align: center;
  font-size: 0.875rem;
  color: var(--color-muted);
}

.site-footer a {
  color: var(--color-muted);
}

.site-footer a:hover {
  color: var(--color-accent);
}

.site-footer__links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 0.5rem;
}

@media (max-width: 480px) {
  .site-header__inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-nav {
    flex-wrap: wrap;
    gap: 0.75rem 1.25rem;
  }

  main {
    padding-top: 1.75rem;
  }
}