:root {
  color-scheme: light dark;
  --bg: #050b18;
  --card: rgba(255, 255, 255, 0.07);
  --text: #f2f2f2;
  --accent: #76d1ff;
  --muted: #aab7c8;
  font-family: 'SF Pro Display', 'Inter', 'Noto Sans JP', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

body {
  margin: 0;
  padding: 0 16px 48px;
  background: radial-gradient(circle at top, rgba(118, 209, 255, 0.15), transparent 40%), var(--bg);
  color: var(--text);
  line-height: 1.6;
}

main {
  max-width: 820px;
  margin: 0 auto;
}

header {
  text-align: center;
  padding: 48px 0 24px;
}

h1 {
  font-size: 2.4rem;
  margin-bottom: 0.25em;
}

nav {
  background: var(--card);
  border-radius: 16px;
  display: flex;
  justify-content: center;
  gap: 16px;
  padding: 12px;
}

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

a:hover {
  text-decoration: underline;
}

section {
  background: var(--card);
  border-radius: 18px;
  padding: 24px;
  margin-top: 24px;
}

h2 {
  margin-top: 0;
}

ul {
  padding-left: 20px;
}

.language-block {
  margin-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 18px;
}

.language-label {
  font-size: 0.9rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

footer {
  text-align: center;
  margin-top: 32px;
  color: var(--muted);
  font-size: 0.9rem;
}