:root {
  color-scheme: dark;
  --background: #090a10;
  --surface: #151824;
  --surface-raised: #1d2130;
  --text: #f8f9ff;
  --muted: #aeb4c7;
  --pink: #ff4c94;
  --yellow: #f7db4f;
  --cyan: #5ae5f4;
  --line: rgba(255, 255, 255, 0.11);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background:
    radial-gradient(circle at 80% -10%, rgba(90, 229, 244, 0.16), transparent 34rem),
    radial-gradient(circle at -10% 18%, rgba(255, 76, 148, 0.13), transparent 30rem),
    var(--background);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  line-height: 1.75;
}

a { color: var(--cyan); }
a:hover { color: var(--yellow); }

.shell { width: min(720px, calc(100% - 40px)); margin: 0 auto; }

header { padding: 34px 0 18px; }

.brand {
  color: var(--text);
  font-size: 1.55rem;
  font-weight: 900;
  letter-spacing: -0.04em;
  text-decoration: none;
}

.brand span { color: var(--pink); }

nav { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 18px; }
nav a { color: var(--muted); font-size: 0.9rem; font-weight: 700; text-decoration: none; }
nav a[aria-current="page"] { color: var(--cyan); }

main { padding: 26px 0 72px; }

.hero, article {
  border: 1px solid var(--line);
  border-radius: 28px;
  background: rgba(21, 24, 36, 0.86);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.28);
}

.hero { padding: clamp(28px, 7vw, 54px); }
article { padding: clamp(24px, 5vw, 46px); }

.eyebrow {
  color: var(--yellow);
  font-size: 0.76rem;
  font-weight: 900;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

h1, h2, h3 { line-height: 1.18; letter-spacing: -0.035em; }
h1 { margin: 10px 0 16px; font-size: clamp(2.3rem, 11vw, 4.8rem); }
h2 { margin-top: 42px; font-size: 1.45rem; }
h3 { margin-top: 26px; font-size: 1.05rem; }

p, li { color: var(--muted); }
strong { color: var(--text); }

.cards { display: grid; gap: 12px; margin-top: 26px; }
.card {
  display: block;
  padding: 19px 20px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface-raised);
  color: var(--text);
  font-weight: 800;
  text-decoration: none;
}
.card small { display: block; color: var(--muted); font-weight: 600; }

.notice {
  margin: 24px 0;
  padding: 14px 16px;
  border-left: 3px solid var(--pink);
  border-radius: 12px;
  background: rgba(255, 76, 148, 0.09);
  color: var(--muted);
}

footer { padding: 24px 0 42px; color: var(--muted); font-size: 0.82rem; }