:root {
  --text: #1f2937;
  --bg: #f9fafb;
  --card: #ffffff;
  --link: #2563eb;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--text);
  background: var(--bg);
}

header {
  background: var(--card);
  border-bottom: 1px solid #e5e7eb;
  position: sticky;
  top: 0;
}

nav {
  max-width: 960px;
  margin: 0 auto;
  padding: 12px 16px;
  display: flex;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.title {
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  display: flex;
  align-items: center;
}

.nav-links {
  display: flex;
  gap: 8px;
}

nav a {
  color: var(--link);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: 6px;
}

main {
  max-width: 960px;
  margin: 24px auto;
  padding: 0 16px 48px;
}

section {
  background: var(--card);
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.card {
  background: var(--card);
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 16px;
}