:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-muted: #5a5a5a;
  --color-accent: #2b6cb0;
  --color-border: #e2e2e2;
  --max-width: 960px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #121212;
    --color-text: #f0f0f0;
    --color-muted: #a0a0a0;
    --color-accent: #6ea8dc;
    --color-border: #2a2a2a;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

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

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
}

.site-title {
  font-weight: 700;
  font-size: 1.1rem;
  text-decoration: none;
  color: var(--color-text);
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  text-decoration: none;
  color: var(--color-muted);
  font-weight: 500;
  padding-bottom: 0.25rem;
  border-bottom: 2px solid transparent;
}

.nav-links a:hover {
  color: var(--color-text);
}

.nav-links a.active {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem;
  min-height: 60vh;
}

main h1 {
  font-size: 2rem;
  margin-bottom: 1rem;
}

main p {
  color: var(--color-muted);
  max-width: 640px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.card {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 1.5rem;
}

.card h2 {
  font-size: 1.1rem;
  margin-top: 0;
}

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

form {
  max-width: 480px;
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

label {
  font-weight: 500;
  font-size: 0.9rem;
}

input,
textarea {
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  font: inherit;
  background: var(--color-bg);
  color: var(--color-text);
}

button {
  align-self: flex-start;
  padding: 0.65rem 1.5rem;
  background: var(--color-accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-weight: 600;
  cursor: pointer;
}

button:hover {
  opacity: 0.9;
}

footer {
  border-top: 1px solid var(--color-border);
  padding: 1.5rem;
  text-align: center;
  color: var(--color-muted);
  font-size: 0.85rem;
}