/* Top-level classroom gateway. Four large native disclosure sections replace
   the old full-width buttons and make 241 courses navigable without opening a
   wall of links on arrival. */
.classrooms-library {
  padding-top: 24px;
}

.classrooms-library__head {
  align-items: flex-end;
  border-bottom: 1px solid #dddcc8;
  display: flex;
  gap: 18px;
  justify-content: space-between;
  margin-bottom: 10px;
  padding: 0 2px 9px;
}

.classrooms-library__head h2 {
  color: #4e0d0d;
  font-family: "Songti SC", "SimSun", "宋体", serif;
  font-size: 1.18em;
  font-weight: 600;
  margin: 0;
}

.classrooms-library__head p {
  color: #8a7a6a;
  font-size: 0.82em;
  line-height: 1.5;
  margin: 3px 0 0;
}

.classrooms-room {
  background-color: rgba(255, 255, 255, 0.72);
  border: 1px solid #d6d5c1;
  border-radius: 12px;
  margin-bottom: 10px;
  overflow: hidden;
  transition:
    border-color 0.15s ease,
    box-shadow 0.15s ease;
}

.classrooms-room[open] {
  border-color: #c9c6aa;
  box-shadow: 0 6px 18px rgba(62, 47, 25, 0.07);
}

.classrooms-room > summary {
  align-items: center;
  cursor: pointer;
  display: flex;
  gap: 12px;
  list-style: none;
  min-height: 66px;
  padding: 12px 18px;
  transition: background-color 0.15s ease;
  user-select: none;
}

.classrooms-room > summary::-webkit-details-marker {
  display: none;
}

.classrooms-room > summary:hover {
  background-color: #fbfbf4;
}

.classrooms-room > summary::after {
  color: #aaa994;
  content: "\203A";
  flex: none;
  font-size: 1.4em;
  line-height: 1;
  margin-left: 4px;
  transition: transform 0.15s ease;
}

.classrooms-room[open] > summary::after {
  transform: rotate(90deg);
}

.classrooms-room__mark {
  align-items: center;
  background-color: #f2eddd;
  border: 1px solid #ded6bb;
  border-radius: 10px;
  color: #4a7c59;
  display: flex;
  flex: none;
  height: 40px;
  justify-content: center;
  width: 40px;
}

.classrooms-room__title {
  color: #4e0d0d;
  font-family: "Songti SC", "SimSun", "宋体", serif;
  font-size: 1.16em;
  font-weight: 600;
}

.classrooms-room__count {
  color: #8a7a6a;
  font-size: 0.8em;
  font-variant-numeric: tabular-nums;
  margin-left: auto;
  white-space: nowrap;
}

.classrooms-room__body {
  border-top: 1px solid #e9e7d7;
  padding: 14px;
}

.classrooms-categories {
  display: grid;
  gap: 9px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.classrooms-category {
  background-color: #fbfaf3;
  border: 1px solid #e0deca;
  border-radius: 9px;
  min-width: 0;
  padding: 14px;
}

.classrooms-category__head {
  align-items: baseline;
  border-bottom: 1px solid #ebe8d7;
  display: flex;
  gap: 10px;
  justify-content: space-between;
  margin-bottom: 10px;
  padding-bottom: 8px;
}

.classrooms-category__head h3 {
  font-family: "Songti SC", "SimSun", "宋体", serif;
  font-size: 1em;
  line-height: 1.4;
  margin: 0;
}

.classrooms-category__head h3 a {
  color: #4e0d0d;
  text-decoration: none;
}

.classrooms-category__head h3 a:hover {
  color: #1a5276;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.classrooms-category__head > span {
  color: #8a7a6a;
  flex: none;
  font-size: 0.75em;
  white-space: nowrap;
}

.classrooms-category .course-chips {
  gap: 6px;
  justify-content: flex-start;
  margin: 0;
}

.classrooms-category .course-chip {
  align-items: center;
  background-color: #fff;
  border-color: #dfdcc8;
  box-sizing: border-box;
  display: inline-flex;
  font-size: 0.82em;
  line-height: 1.4;
  min-height: 44px;
  padding: 6px 10px;
  text-decoration: none;
  transition:
    background-color 0.15s ease,
    border-color 0.15s ease,
    color 0.15s ease;
}

.classrooms-category .course-chip:hover {
  background-color: #fffef9;
  border-color: #9b9277;
  color: #4e0d0d;
  text-decoration: none;
}

.classrooms-category__all {
  color: #4a7c59;
  display: inline-flex;
  font-size: 0.78em;
  gap: 5px;
  margin-top: 10px;
  align-items: center;
  min-height: 44px;
  text-decoration: none;
}

.classrooms-category__all:hover {
  color: #365e42;
  text-decoration: underline;
}

.classrooms-room__all {
  align-items: center;
  background-color: #4a7c59;
  border: 1px solid #4a7c59;
  border-radius: 999px;
  color: #fff;
  display: inline-flex;
  font-size: 0.82em;
  gap: 6px;
  justify-content: center;
  margin-top: 14px;
  min-height: 44px;
  padding: 6px 16px;
  text-decoration: none;
  transition:
    background-color 0.15s ease,
    border-color 0.15s ease;
}

.classrooms-room__all:hover {
  background-color: #365e42;
  border-color: #365e42;
  color: #fff;
  text-decoration: none;
}

.classrooms-room__empty {
  color: #8a7a6a;
  margin: 8px;
  text-align: center;
}

.classrooms-room > summary:focus-visible,
.classrooms-category a:focus-visible,
.classrooms-room__all:focus-visible {
  outline: 3px solid rgba(26, 82, 118, 0.35);
  outline-offset: 2px;
}

@media screen and (max-width: 800px) {
  .classrooms-library__head {
    align-items: stretch;
    flex-direction: column;
    gap: 10px;
  }

  .classrooms-categories {
    grid-template-columns: 1fr;
  }
}

@media screen and (max-width: 520px) {
  .classrooms-room > summary {
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 8px 10px;
    padding: 12px;
  }

  .classrooms-room__mark {
    height: 36px;
    width: 36px;
  }

  .classrooms-room__title {
    align-self: center;
  }

  .classrooms-room__count {
    flex-basis: calc(100% - 46px);
    margin-left: 46px;
    margin-top: -12px;
  }

  .classrooms-room > summary::after {
    margin-left: auto;
    margin-top: 8px;
    order: 2;
  }

  .classrooms-room__body {
    padding: 10px;
  }

  .classrooms-category {
    padding: 12px;
  }

  .classrooms-category .course-chips li {
    width: 100%;
  }

  .classrooms-category .course-chip {
    display: flex;
    min-height: 44px;
    width: 100%;
  }

  .classrooms-category__all {
    align-items: center;
    min-height: 44px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .classrooms-page *,
  .classrooms-page *::before,
  .classrooms-page *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}