:root {
  --bg: #ffffff;
  --surface: #f8fafc;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --ptl: #4f46e5;
  --qr: #2563eb;
  --accent: var(--ptl);
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1020;
    --surface: #131a2e;
    --text: #f1f5f9;
    --muted: #94a3b8;
    --border: #243049;
    --ptl: #818cf8;
    --qr: #3b82f6;
  }
}

body.qr {
  --accent: var(--qr);
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.65;
}

.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

header.site {
  border-bottom: 1px solid var(--border);
}

header.site .wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding-top: 1rem;
  padding-bottom: 1rem;
}

.brand {
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
}

nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

main.wrap {
  padding-top: 2.5rem;
  padding-bottom: 3rem;
}

h1,
h2,
h3 {
  line-height: 1.25;
  margin: 0;
}

h1 {
  font-size: 2rem;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

h2 {
  font-size: 1.35rem;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

h3 {
  font-size: 1.1rem;
  margin-top: 1.75rem;
  margin-bottom: 0.5rem;
}

p,
ul,
ol,
dl {
  margin: 0 0 1rem;
}

ul,
ol {
  padding-left: 1.4rem;
}

li {
  margin-bottom: 0.4rem;
}

a {
  color: var(--accent);
  text-underline-offset: 0.18em;
}

a:hover {
  text-decoration-thickness: 2px;
}

a:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.05em 0.35em;
  overflow-wrap: anywhere;
}

.lead {
  font-size: 1.2rem;
  color: var(--muted);
}

.meta {
  color: var(--muted);
  font-size: 0.95rem;
}

.summary {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  padding: 1rem 1.25rem 0.5rem;
  margin: 1.5rem 0 0;
}

.summary h2 {
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
  padding: 0;
  border: 0;
}

.cards {
  display: grid;
  gap: 1.25rem;
  margin-top: 2rem;
}

@media (min-width: 640px) {
  .cards {
    grid-template-columns: 1fr 1fr;
  }
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: 4px solid var(--accent);
  border-radius: 8px;
  padding: 1.25rem;
}

.card.ptl,
.faq.ptl {
  --accent: var(--ptl);
}

.card.qr,
.faq.qr {
  --accent: var(--qr);
}

.card h2 {
  font-size: 1.3rem;
  margin: 0 0 0.5rem;
  padding: 0;
  border: 0;
  color: var(--accent);
}

.card ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.faq h3 {
  margin-top: 1.5rem;
}

footer.site {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.95rem;
}

footer.site .wrap {
  padding-top: 1.5rem;
  padding-bottom: 2rem;
}

footer.site p {
  margin-bottom: 0.4rem;
}

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

@media (max-width: 480px) {
  h1 {
    font-size: 1.65rem;
  }

  main.wrap {
    padding-top: 1.75rem;
  }
}