body {
  background-color: #0b0231;
  color: #3b2412;
  margin: 0;
}
img {
  display: block;
  max-width: 100%;
  height: auto;
  margin-left: auto;
  margin-right: auto;
}


.page-center {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 12px 72px;
  box-sizing: border-box;
  background-color: #e8f2fb;
  border-radius: 14px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.35);
}


.page-title {
  text-align: center;
  margin-bottom: 16px;
}

.page-title img {
  display: block;
  max-width: 100%;
  height: auto;
  margin-left: auto;
  margin-right: auto;
}

.illustration {
  text-align: center;
  margin: 20px 0;
}

.illustration img {
  display: block;
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  margin-left: auto;
  margin-right: auto;
}

.illustration figcaption {
  font-size: 0.9em;
  color: #6b4a2a;
  margin-top: 6px;
}

.section-heading {
  margin: 32px 0 8px;
  padding-left: 6px;
  border-left: 6px solid #2f6fb3;
  font-weight: 700;
  color: #1a3a5c;
  flex-basis: 100%;
}

.nav-group {
  flex-basis: 100%;
}

.nav-group::details-content {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: 10px;
}

.nav-group summary.section-heading {
  cursor: pointer;
}

.link-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start;
  gap: 10px;
  max-width: 760px;
  margin: 12px auto 24px;
}

.link-nav a {
  display: block;
  box-sizing: border-box;
  padding: 8px 14px;
  background-color: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(0, 0, 0, 0.2);
  border-radius: 10px;
  color: #1a1a2e;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.25);
  font-weight: 700;
  font-size: 14px;
  line-height: 1.3;
  text-align: center;
  text-decoration: none;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.25);
  transition: background-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.link-nav a:visited,
.link-nav a:active {
  color: #1a1a2e;
}

.link-nav a:hover,
.link-nav a:focus-visible {
  background-color: rgba(255, 255, 255, 1);
  transform: scale(1.1);
  box-shadow: 0 5px 12px rgba(0, 0, 0, 0.35);
}

.link-nav a.nav-link-last-clicked {
  background-color: rgba(90, 58, 122, 0.18);
  border-color: rgba(90, 58, 122, 0.5);
  color: #5a3a7a;
}

p {
  line-height: 1.8;
  text-indent: 1em;
  margin: 14px 0;
}

a { color: #b5651d; }
a:visited { color: #8a4a9a; }
a:active { color: #cc5500; }

.extra-links {
  text-align: center;
  text-indent: 0;
  margin: 8px 0;
  color: #8a6a4a;
}

.img-sekai-meguri    { width: 394px; max-width: 100%; height: auto; }