:root {
  --bg: #0b1220;
  --card: rgba(255, 255, 255, 0.06);
  --card-border: rgba(255, 255, 255, 0.12);
  --text: rgba(255, 255, 255, 0.92);
  --muted: rgba(255, 255, 255, 0.72);
  --link: #8ab4ff;
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.45);
  --radius: 16px;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  color: var(--text);
  background: radial-gradient(
      900px 500px at 20% 10%,
      rgba(138, 180, 255, 0.18),
      transparent 60%
    ),
    radial-gradient(
      700px 500px at 85% 25%,
      rgba(168, 255, 214, 0.12),
      transparent 60%
    ),
    var(--bg);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto,
    "Noto Sans JP", "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, Arial,
    "Apple Color Emoji", "Segoe UI Emoji";
  line-height: 1.65;
  letter-spacing: 0.01em;
}

main {
  width: min(920px, calc(100% - 40px));
  margin: 64px auto;
  padding: 28px 28px 22px;
  border: 1px solid var(--card-border);
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

h1 {
  margin: 0 0 10px;
  font-size: clamp(28px, 3.2vw, 40px);
  letter-spacing: 0.02em;
}

h2 {
  margin: 0 0 8px;
  font-size: 16px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

p {
  margin: 0;
}

section {
  margin-top: 18px;
  padding: 16px 16px;
  border: 1px solid var(--card-border);
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.12);
}

footer {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--card-border);
  color: var(--muted);
}

small {
  font-size: 12px;
}

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

a:hover {
  text-decoration: underline;
}

a:focus-visible {
  outline: 2px solid rgba(138, 180, 255, 0.7);
  outline-offset: 3px;
  border-radius: 6px;
}

@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
  }
}