.youtube-eiketsu-related {
  display: grid;
  gap: 4px;
  margin-top: 10px;
  padding: 8px 10px;
  border-left: 3px solid var(--accent-2);
  background: #f4f6f3;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.55;
}

.youtube-eiketsu-related strong {
  color: var(--ink);
  font-size: 12px;
}

.youtube-eiketsu-related ul {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.youtube-eiketsu-related li {
  min-width: 0;
}

.youtube-eiketsu-related li + li {
  padding-top: 10px;
  border-top: 1px solid rgba(39, 61, 57, 0.14);
}

.youtube-eiketsu-related a {
  color: var(--accent-2);
  font-weight: 700;
  text-decoration: none;
}

.youtube-eiketsu-video-link {
  display: grid;
  grid-template-columns: minmax(128px, 168px) minmax(0, 1fr);
  align-items: start;
  gap: 10px;
  min-width: 0;
}

.youtube-eiketsu-thumbnail {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 4px;
  background: #dfe5e1;
}

.youtube-eiketsu-video-copy {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  min-width: 0;
  align-content: start;
}

.youtube-eiketsu-video-title {
  color: var(--accent-2);
  font-weight: 700;
  line-height: 1.45;
}

.youtube-eiketsu-video-meta {
  color: var(--muted);
  font-size: 11px;
  font-weight: 500;
  line-height: 1.4;
}

.youtube-eiketsu-related a:hover {
  color: var(--accent);
  text-decoration: underline;
}

.youtube-eiketsu-related small {
  color: var(--muted);
  font-size: 11px;
}

@media (max-width: 640px) {
  .youtube-eiketsu-related {
    padding-inline: 8px;
    font-size: 11px;
  }

  .youtube-eiketsu-video-link {
    grid-template-columns: 128px minmax(0, 1fr);
    gap: 8px;
  }

  .youtube-eiketsu-related strong,
  .youtube-eiketsu-related small {
    font-size: 11px;
  }

  .youtube-eiketsu-video-title,
  .youtube-eiketsu-video-meta {
    font-size: 11px;
  }
}

/* 英傑の個別ページ上部の「紹介動画」。章を囲むカードにせず、罫線と余白で区切る（DESIGN.md）。 */
.youtube-eiketsu-top {
  margin-top: 0;
  padding: 14px 0 4px;
  border-bottom: 1px solid var(--line);
}

.youtube-eiketsu-top[hidden] {
  display: none;
}

.youtube-eiketsu-top h2 {
  margin-bottom: 10px;
}

.youtube-eiketsu-top .youtube-eiketsu-related {
  margin-top: 0;
  padding: 0 0 10px;
  border-left: 0;
  background: none;
}

.youtube-eiketsu-top .youtube-eiketsu-related ul {
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr));
  gap: 12px 18px;
}

.youtube-eiketsu-top .youtube-eiketsu-related li + li {
  padding-top: 0;
  border-top: 0;
}

.youtube-eiketsu-more summary {
  width: fit-content;
  margin: 10px 0;
  color: var(--accent-2);
  font-weight: 700;
  cursor: pointer;
}

@media (max-width: 640px) {
  .youtube-eiketsu-top {
    padding-top: 12px;
  }

  .youtube-eiketsu-top .youtube-eiketsu-related ul {
    grid-template-columns: minmax(0, 1fr);
  }
}