/* ---- Topic sections (Math, Philosophy, Science) ---- */
.learn-topic {
  display: grid;
  gap: 0.75rem;
  animation: learnCardIn 0.4s ease both;
}
.learn-topic[hidden] { display: none !important; }
.learn-topic-head {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  justify-content: space-between;
  align-items: flex-end;
}
.learn-topic-head h2 {
  margin: 0 0 0.25rem;
  font-size: 1.35rem;
  font-style: italic;
  color: var(--alb-accent-deep);
}
.learn-topic-head p {
  margin: 0;
  max-width: 36rem;
  color: var(--alb-muted);
  font-size: 0.92rem;
}
.learn-topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 0.85rem;
}
.topic-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.5rem;
  padding: 1rem;
  border-radius: 16px;
  border: 1px solid rgba(148, 163, 184, 0.35);
  background:
    url("./images/panel-card.svg") center / cover no-repeat,
    linear-gradient(160deg, #0f172a 0%, #102a43 100%);
  color: #e8f1fb;
}
.topic-icon {
  width: 2rem;
  height: 2rem;
}
.mode-icon {
  width: 1em;
  height: 1em;
  vertical-align: -0.12em;
}
details.topic-card {
  padding: 0;
  overflow: hidden;
}
.topic-summary {
  display: grid;
  gap: 0.5rem;
  align-items: start;
  padding: 1rem;
  cursor: pointer;
  list-style: none;
}
.topic-summary::marker {
  content: "";
}
.topic-summary::-webkit-details-marker {
  display: none;
}
.topic-summary:focus-visible {
  outline: 2px solid #7dd3fc;
  outline-offset: 3px;
  border-radius: 12px;
}
.topic-summary-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  width: 100%;
}
.topic-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.45);
  color: #e2e8f0;
  font-weight: 800;
  line-height: 1;
  transition: transform 0.15s ease, background 0.15s ease;
}
.topic-card[open] {
  border-color: rgba(124, 255, 178, 0.55);
}
.topic-card[open] .topic-toggle {
  transform: rotate(45deg);
  background: rgba(124, 255, 178, 0.12);
}
.topic-title {
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
}
.topic-blurb {
  font-size: 0.82rem;
  color: #cbd5e1;
  line-height: 1.35;
}
.topic-detail {
  display: grid;
  gap: 0.45rem;
  margin: 0 1rem 1rem;
  padding-top: 0.65rem;
  border-top: 1px solid rgba(148, 163, 184, 0.25);
}
.topic-detail-title {
  margin: 0;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: #e2e8f0;
}
.topic-card h3 {
  margin: 0;
  font-size: 1rem;
  color: #fff;
}
.topic-card p {
  margin: 0;
  font-size: 0.82rem;
  color: #cbd5e1;
  line-height: 1.35;
}
.topic-list {
  margin: 0.1rem 0 0;
  padding-left: 1.1rem;
  display: grid;
  gap: 0.18rem;
  font-size: 0.78rem;
  color: #cbd5e1;
  line-height: 1.35;
}
.topic-list.lessons {
  list-style: decimal;
}
.topic-meta {
  font-size: 0.76rem;
  color: #94a3b8;
}
.topic-meta strong {
  color: #e2e8f0;
}
.topic-tag {
  margin-top: auto;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: #94a3b8;
  border: 1px solid rgba(148, 163, 184, 0.35);
  border-radius: 999px;
  padding: 0.2rem 0.6rem;
}