:root {
  color-scheme: light;
  --ink: #263238;
  --muted: #65757b;
  --paper: #fffdfb;
  --soft: #f7eee9;
  --line: #eaded7;
  --accent: #c25c68;
  --accent-dark: #8d3b47;
  --teal: #2e5a69;
  --sage: #dfe9e5;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Noto Sans JP", "Hiragino Sans", "Yu Gothic", system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.85;
}
a { color: inherit; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px clamp(18px, 4vw, 56px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 253, 251, 0.94);
  backdrop-filter: blur(12px);
}
.brand {
  font-weight: 800;
  text-decoration: none;
  color: var(--teal);
  white-space: nowrap;
}
.site-nav {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
}
.site-nav a {
  flex: 0 0 auto;
  padding: 8px 10px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}
.site-nav a[aria-current="page"], .site-nav a:hover {
  color: var(--teal);
  background: var(--soft);
}
main {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.03fr) minmax(320px, 0.82fr);
  gap: clamp(24px, 5vw, 64px);
  align-items: center;
  min-height: min(760px, calc(100vh - 70px));
  padding: clamp(32px, 7vw, 82px) 0 32px;
}
.eyebrow {
  margin: 0 0 12px;
  color: var(--accent-dark);
  font-weight: 800;
}
h1 {
  margin: 0;
  font-size: clamp(32px, 5vw, 60px);
  line-height: 1.18;
  letter-spacing: 0;
}
.lead {
  max-width: 720px;
  margin: 20px 0 0;
  color: #40545b;
  font-size: 18px;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 18px;
  border-radius: 6px;
  font-weight: 800;
  text-decoration: none;
}
.button.primary {
  background: var(--accent);
  color: #fff;
}
.button.secondary {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--teal);
}
.hero-visual { margin: 0; }
.hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 5 / 3;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: 0 22px 55px rgba(38, 50, 56, 0.15);
}
.notice {
  margin: 0 0 28px;
  padding: 20px 22px;
  border-left: 5px solid var(--accent);
  background: var(--soft);
}
.notice strong {
  display: block;
  margin-bottom: 4px;
  color: var(--teal);
}
.notice p { margin: 0; }
.content-section {
  padding: 34px 0;
  border-top: 1px solid var(--line);
}
.content-section h2 {
  margin: 0 0 14px;
  color: var(--teal);
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.35;
}
.content-section p {
  max-width: 880px;
  margin: 0 0 12px;
}
details {
  max-width: 900px;
  margin-bottom: 10px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}
summary {
  cursor: pointer;
  color: var(--teal);
  font-weight: 800;
}
details p { margin-top: 10px; }
.related-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.related-card {
  min-height: 136px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  text-decoration: none;
}
.related-card span {
  display: block;
  color: var(--teal);
  font-weight: 800;
}
.related-card small {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}
.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px 18px;
  padding: 34px 20px;
  border-top: 1px solid var(--line);
  color: var(--muted);
}
.site-footer p { margin: 0; }
.site-footer a { color: var(--teal); }
@media (max-width: 780px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }
  .site-nav { width: 100%; }
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 30px;
  }
  .lead { font-size: 16px; }
  .hero-actions { flex-direction: column; }
  .button { width: 100%; }
  .related-grid { grid-template-columns: 1fr; }
}