/* History-only reader polish. Keep shared Mathematics reader styling untouched. */
html {
  background: #050914;
  color-scheme: dark;
}

body.physics-body {
  min-height: 100vh;
  background-color: #050914;
}

/* Use the actual AceBGCSE favicon artwork for the global reader brand mark. */
.ace-reader-brand-mark {
  font-size: 0 !important;
  overflow: hidden;
  background: #1FB6FF url('/favicon-v2.svg?v=20260809-history-ui-1') center / 100% 100% no-repeat !important;
  box-shadow: 0 0 22px rgba(31, 182, 255, .24) !important;
}

/* History keeps its subject initial, but matches the favicon's blue/white treatment. */
.course-logo .logo-mark {
  background: #1FB6FF !important;
  color: #ffffff !important;
  -webkit-text-fill-color: #ffffff !important;
  text-shadow: 0 1px 2px rgba(0, 0, 0, .18);
  box-shadow: 0 0 20px rgba(31, 182, 255, .20);
}

/* Prevent the browser's white root canvas from flashing during large objective jumps. */
.physics-reader-shell,
.physics-main,
#historyLessonContent {
  background-color: transparent;
}

.objective-panel {
  scroll-margin-top: 92px;
}

/* Mastery checks are interactive in History. */
.note-content .task-list input[type='checkbox'] {
  width: 17px;
  height: 17px;
  flex: 0 0 17px;
  margin-top: .48em;
  cursor: pointer;
  opacity: 1;
  accent-color: #1FB6FF;
}

.note-content .task-list input[type='checkbox']:focus-visible {
  outline: 2px solid rgba(31, 182, 255, .75);
  outline-offset: 3px;
}

.note-content .task-list li:has(input[type='checkbox']:checked) span {
  color: #a7f3d0;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto !important; }
}