:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-muted: #55555f;
  --color-border: #d9d9e0;
  --color-accent: #2451c4;
  --color-card-bg: #f7f7fa;
  --focus-ring: #2451c4;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #121216;
    --color-text: #f2f2f5;
    --color-muted: #b5b5c0;
    --color-border: #33333c;
    --color-accent: #7fa4ff;
    --color-card-bg: #1c1c22;
    --focus-ring: #7fa4ff;
  }
}

* {
  box-sizing: border-box;
}

html {
  font-size: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--color-accent);
  color: #fff;
  padding: 0.75rem 1rem;
  z-index: 100;
}

.skip-link:focus {
  left: 0.5rem;
  top: 0.5rem;
}

.site-header {
  padding: 2.5rem 1.5rem 1rem;
  max-width: 40rem;
  margin: 0 auto;
  width: 100%;
}

.site-header h1 {
  font-size: 1.75rem;
  margin: 0;
}

main {
  flex: 1;
  max-width: 40rem;
  margin: 0 auto;
  padding: 0 1.5rem 2.5rem;
  width: 100%;
}

.intro {
  color: var(--color-muted);
  margin-top: 0;
}

.card-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

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

.card {
  border: 1px solid var(--color-border);
  border-radius: 0.75rem;
  background: var(--color-card-bg);
}

.card-link {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  height: 100%;
  padding: 1.25rem;
  color: inherit;
  text-decoration: none;
  border-radius: inherit;
}

.card-link:hover {
  border-color: var(--color-accent);
}

.card-link:focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 2px;
}

.card-title {
  margin: 0;
  font-size: 1.15rem;
  color: var(--color-text);
}

.card-description {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.95rem;
  flex: 1;
}

.card-cta {
  color: var(--color-accent);
  font-weight: 600;
  font-size: 0.9rem;
}

.site-footer {
  max-width: 40rem;
  margin: 0 auto;
  padding: 1.5rem;
  width: 100%;
  color: var(--color-muted);
  font-size: 0.85rem;
  text-align: center;
}

@media (prefers-reduced-motion: no-preference) {
  .card-link {
    transition: border-color 0.15s ease;
  }
}