.course-image-library {
  margin: 1.5rem 0 2rem;
  border: 1px solid #c9dce8;
  border-radius: 1.1rem;
  background: #f7fbfd;
  overflow: clip;
}

.course-image-library summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.2rem;
  cursor: pointer;
  color: #09213a;
  font-weight: 800;
  list-style: none;
}

.course-image-library summary::-webkit-details-marker { display: none; }
.course-image-library summary::after { content: "+"; font-size: 1.5rem; line-height: 1; }
.course-image-library[open] summary::after { content: "−"; }
.course-image-library summary span { display: block; margin-top: .2rem; color: #537083; font-size: .82rem; font-weight: 500; }

.course-image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr));
  gap: 1rem;
  padding: 0 1rem 1rem;
}

.course-image-grid figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid #d8e5ed;
  border-radius: .85rem;
  background: #fff;
}

.course-image-grid img {
  display: block;
  width: 100%;
  height: clamp(11rem, 24vw, 16rem);
  object-fit: contain;
  background: #eef4f7;
}

.course-image-grid figcaption {
  padding: .75rem .85rem .9rem;
  color: #29485d;
  font-size: .9rem;
  line-height: 1.4;
}

.course-image-grid figcaption strong { display: block; color: #09213a; }
.course-image-grid .answer-key { border-color: #d8bf75; }
.course-image-grid .answer-key figcaption { background: #fff9e8; }

@media (max-width: 600px) {
  .course-image-library { margin-inline: 0; }
  .course-image-library summary { align-items: flex-start; padding: .9rem 1rem; }
  .course-image-grid { grid-template-columns: 1fr; }
  .course-image-grid img { height: auto; max-height: 24rem; }
}