:root {
  color-scheme: light;
  --paper: #f5f1e7;
  --ink: #19231f;
  --muted: #606b66;
  --line: #c7cec8;
  font-family:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Yu Gothic UI', 'Yu Gothic', sans-serif;
}
html[lang='en'] [data-lang='ja'],
html[lang='ja'] [data-lang='en'] {
  display: none !important;
}
* {
  box-sizing: border-box;
}
body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.75;
}
a {
  color: inherit;
  text-underline-offset: 0.18em;
}
.head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 2rem;
  min-height: 62px;
  padding: 0 max(1rem, calc((100vw - 920px) / 2));
  border-bottom: 1px solid var(--line);
}
.brand {
  font-weight: 800;
  letter-spacing: 0.08em;
  text-decoration: none;
}
.head nav,
.foot nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}
.head nav a {
  color: var(--muted);
  font-size: 0.78rem;
}
#lang-toggle {
  padding: 0;
  color: var(--muted);
  font: inherit;
  font-size: 0.78rem;
  text-decoration: underline;
  text-underline-offset: 0.18em;
  background: none;
  border: 0;
  cursor: pointer;
}
.page {
  width: min(100% - 2rem, 920px);
  margin: auto;
  padding: clamp(2.5rem, 7vw, 5rem) 0;
}
.hero {
  max-width: 700px;
  margin-bottom: 2rem;
}
.kicker {
  margin: 0 0 0.5rem;
  color: var(--muted);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}
.hero h1 {
  margin: 0 0 1rem;
  font-size: clamp(2.2rem, 7vw, 4.5rem);
  line-height: 1;
}
.hero p {
  color: var(--muted);
  font-size: 1rem;
}
.button {
  display: inline-block;
  margin-top: 0.7rem;
  padding: 0.65rem 1rem;
  color: var(--paper);
  font-weight: 700;
  text-decoration: none;
  background: var(--ink);
  border-radius: 4px;
}
.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.card,
.prose {
  padding: 1.35rem;
  background: rgba(255, 255, 255, 0.42);
  border: 1px solid var(--line);
  border-radius: 7px;
}
.card h2,
.prose h2 {
  margin-top: 0;
  font-size: 1rem;
}
.card p,
.card li,
.prose p,
.prose li {
  color: #46504c;
  font-size: 0.9rem;
}
.prose {
  grid-column: 1/-1;
}
.prose h2 {
  margin-top: 2rem;
}
.prose h2:first-child {
  margin-top: 0;
}
.foot {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  width: min(100% - 2rem, 920px);
  margin: auto;
  padding: 1.3rem 0 2.5rem;
  color: var(--muted);
  font-size: 0.78rem;
  border-top: 1px solid var(--line);
}
@media (max-width: 650px) {
  .head,
  .foot {
    align-items: flex-start;
    flex-direction: column;
    padding-top: 1rem;
    padding-bottom: 1rem;
  }
  .grid {
    grid-template-columns: 1fr;
  }
  .prose {
    grid-column: auto;
  }
}