.chapter-label { display: block; margin: 12px 0 6px; font-size: 12px; color: #afbdd0; }
#chapter { width: 100%; margin-bottom: 18px; padding: 10px; background: #172439; color: #f0f5ff; border: 1px solid #40526d; border-radius: 6px; }
#chapter-resources { margin-top: 20px; display: grid; gap: 12px; font-size: 12px; }
#chapter-resources[hidden] { display: none; }
#chapter-resources a { color: #a5d8ff; line-height: 1.5; }
#problems button { text-align: left; }
#examples pre { white-space: pre-wrap; overflow-wrap: anywhere; }
@media (min-width: 601px) {
  #problems { max-height: max(240px, calc(100vh - 420px)); overflow-y: auto; overscroll-behavior: contain; }
}