:root {
  color-scheme: light;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
  background: #f7f7f4;
  color: #171717;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  padding: 40px 20px 60px;
  display: flex;
  flex-direction: column;
  align-items: center;
}
main {
  width: min(720px, 100%);
  border: 1px solid #d8d8d2;
  background: #fff;
  border-radius: 8px;
  padding: 36px;
  box-shadow: 0 16px 48px rgba(20, 20, 20, 0.08);
}
h1 {
  margin: 0 0 8px;
  font-size: 26px;
  line-height: 1.25;
}
h2 {
  margin: 28px 0 8px;
  font-size: 17px;
  line-height: 1.35;
  border-bottom: 1px solid #ecece7;
  padding-bottom: 6px;
}
p, li {
  color: #3c3f3a;
  line-height: 1.75;
  font-size: 14.5px;
}
ul { padding-left: 22px; }
.subtitle {
  color: #5f625c;
  margin: 0 0 24px;
}
.updated {
  color: #8a8d86;
  font-size: 12.5px;
  margin: 0 0 24px;
}
.links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}
.btn {
  display: inline-block;
  border-radius: 6px;
  padding: 11px 18px;
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
  color: #fff;
  background: #1f4f46;
}
.btn.secondary {
  color: #171717;
  background: #fff;
  border: 1px solid #c9cbc4;
  font-weight: 600;
}
.btn:hover { opacity: 0.92; }
nav.footer {
  width: min(720px, 100%);
  margin-top: 18px;
  display: flex;
  gap: 18px;
  font-size: 13px;
}
nav.footer a {
  color: #5f625c;
  text-decoration: underline;
  text-underline-offset: 4px;
}
nav.footer a:hover { color: #171717; }