:root {
  color-scheme: light dark;
  --brand: #286a68;
  --brand-soft: #d9efed;
  --ink: #172322;
  --muted: #5d6b69;
  --surface: #ffffff;
  --background: #f4f8f7;
  --border: #d9e4e2;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--background);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", "Noto Sans JP", "PingFang SC", sans-serif;
  line-height: 1.7;
}
a { color: var(--brand); }
.shell { width: min(860px, calc(100% - 32px)); margin: 0 auto; }
header { padding: 28px 0 18px; }
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { color: var(--ink); text-decoration: none; font-size: 1.18rem; font-weight: 750; }
.languages { display: flex; gap: 6px; flex-wrap: wrap; }
.languages button {
  border: 1px solid var(--border); border-radius: 999px; background: var(--surface);
  color: var(--ink); cursor: pointer; padding: 6px 11px; font: inherit;
}
.languages button[aria-pressed="true"] { background: var(--brand); border-color: var(--brand); color: white; }
main { background: var(--surface); border: 1px solid var(--border); border-radius: 26px; padding: clamp(24px, 5vw, 54px); box-shadow: 0 18px 60px rgb(20 62 60 / 8%); }
h1 { margin: 0 0 8px; font-size: clamp(2rem, 6vw, 3.2rem); line-height: 1.15; letter-spacing: -.03em; }
h2 { margin: 2rem 0 .5rem; font-size: 1.25rem; }
p, li { color: var(--muted); }
.lede { font-size: 1.08rem; }
.meta { color: var(--muted); font-size: .92rem; }
.notice { margin: 24px 0; padding: 18px; border-radius: 16px; background: var(--brand-soft); color: #164f4e; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; margin: 26px 0; }
.card { display: block; padding: 20px; border: 1px solid var(--border); border-radius: 18px; text-decoration: none; color: var(--ink); }
.card:hover { border-color: var(--brand); transform: translateY(-1px); }
.card strong { display: block; margin-bottom: 4px; }
.card span { color: var(--muted); }
footer { padding: 24px 0 40px; color: var(--muted); font-size: .9rem; text-align: center; }
[data-lang] { display: none; }
[data-lang].active { display: block; }
span[data-lang].active { display: inline; }
@media (prefers-color-scheme: dark) {
  :root { --ink: #e5f2f0; --muted: #adbfbc; --surface: #14201f; --background: #0d1514; --border: #2d403e; --brand-soft: #173d3b; }
  .notice { color: #c8eeea; }
}