/* The lesson presentation is an app route, with bounded regions between persistent controls. */
.play-body > .app-shell[hidden] { display: none; }
.lesson-presentation {
  --lp-bg: #f8f5ff;
  --lp-surface: #fff;
  --lp-ink: #181818;
  --lp-muted: #665e78;
  --lp-primary: #7545e8;
  --lp-selected: #e8deff;
  --lp-answer: #167050;
  --lp-line: #e7e0f1;
  position: fixed;
  inset: 0;
  z-index: 140;
  width: 100%;
  height: 100vh;
  height: 100dvh;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: auto minmax(0, 1fr) auto;
  overflow: hidden;
  background: var(--lp-bg);
  color: var(--lp-ink);
  font-family: inherit;
  color-scheme: light;
}
.lesson-presentation[hidden], .lesson-presentation [hidden] { display: none !important; }
.lesson-presentation * { box-sizing: border-box; }
.lesson-presentation .lp-header {
  min-width: 0;
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 20px;
  padding: max(8px, env(safe-area-inset-top)) max(20px, env(safe-area-inset-right)) 8px max(20px, env(safe-area-inset-left));
  background: var(--lp-surface);
  border-bottom: 1px solid var(--lp-line);
}
.lesson-presentation .lp-title { margin: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 16px; font-weight: 700; color: var(--lp-ink); }
.lesson-presentation .lp-header-actions, .lesson-presentation .lp-view-actions, .lesson-presentation .lp-reveal, .lesson-presentation .lp-navigation { display: flex; align-items: center; gap: 8px; }
.lesson-presentation .lp-header-actions { gap: 0; }
.lesson-presentation .lp-view-actions { margin-left: 8px; }
.lesson-presentation .lp-annotation-tools { position: relative; flex: 0 0 128px; width: 128px; height: 48px; }
.lesson-presentation .lp-text-tools, .lesson-presentation .lp-drawing-tools { position: absolute; inset: 0; display: flex; align-items: center; justify-content: flex-end; gap: 4px; opacity: 1; visibility: visible; transform: translateY(0) scale(1); transition: opacity 200ms ease, transform 240ms cubic-bezier(.2,.7,.2,1), visibility 0s; }
.lesson-presentation .lp-text-tools[aria-hidden="true"], .lesson-presentation .lp-drawing-tools[aria-hidden="true"] { opacity: 0; visibility: hidden; transform: translateY(5px) scale(.96); pointer-events: none; transition: opacity 200ms ease, transform 240ms cubic-bezier(.2,.7,.2,1), visibility 0s 240ms; }
.lesson-presentation .lp-inline-palette { display: grid; flex: 0 0 auto; width: 0; opacity: 0; visibility: hidden; overflow: hidden; transform: translateX(10px); pointer-events: none; transition: width 320ms cubic-bezier(.2,.7,.2,1), opacity 220ms ease, transform 320ms cubic-bezier(.2,.7,.2,1), visibility 0s 320ms; }
.lesson-presentation .lp-inline-palette[aria-hidden="false"] { width: var(--lp-palette-width, 264px); opacity: 1; visibility: visible; transform: translateX(0); pointer-events: auto; transition-delay: 0s; }
.lesson-presentation .lp-pen-controls, .lesson-presentation .zg-question-highlight__controls { min-height: 0; display: flex; align-items: center; justify-content: flex-end; gap: 8px; padding: 4px; }
.lesson-presentation .zg-question-highlight__colors, .lesson-presentation .zg-question-highlight__history { display: flex; flex: 0 0 auto; gap: 4px; }
.lesson-presentation .zg-question-highlight__colors > button { flex: 0 0 44px; }
.lesson-presentation .lp-pen-colors, .lesson-presentation .lp-pen-history { display: flex; justify-content: center; flex: 0 0 auto; gap: 4px; }
.lesson-presentation [data-image-color] { display: grid; place-items: center; width: 44px; height: 44px; padding: 6px; border: 0; border-radius: 8px; background: transparent; cursor: pointer; }
.lesson-presentation [data-image-color]::before { content: ''; width: 28px; height: 28px; border-radius: 50%; background: var(--pen-color); }
.lesson-presentation [data-image-color][aria-pressed="true"]::before { outline: 2px solid var(--lp-primary); outline-offset: 3px; }
.lesson-presentation [data-image-color]:focus-visible { outline: 3px solid var(--lp-primary); outline-offset: 1px; }
.lesson-presentation .zg-question-highlight { position: relative; flex: 0 0 auto; }
.lesson-presentation [data-question-highlight-color] { display: grid; place-items: center; width: 44px; height: 44px; padding: 6px; border: 0; border-radius: 8px; background: transparent; cursor: pointer; }
.lesson-presentation [data-question-highlight-color]::before { content: ''; width: 28px; height: 28px; border-radius: 50%; background: var(--highlight-color); }
.lesson-presentation [data-question-highlight-color][aria-pressed="true"]::before { outline: 2px solid var(--lp-primary); outline-offset: 3px; }
.lesson-presentation [data-question-highlight-color]:focus-visible { outline: 3px solid var(--lp-primary); outline-offset: 1px; }
.lesson-presentation.is-highlighting .lp-copy { user-select: text; -webkit-user-select: text; cursor: text; }
.lesson-presentation .zg-question-highlight__mark { padding: 0; border-radius: 3px; color: #102c48; box-decoration-break: clone; -webkit-box-decoration-break: clone; }
.lesson-presentation .lp-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-width: 48px;
  min-height: 48px;
  padding: 10px 14px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--lp-ink);
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.25;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 140ms ease, color 140ms ease;
}
.lesson-presentation .lp-button i { font-size: 22px; }
.lesson-presentation .lp-icon { width: 48px; padding: 10px; flex: 0 0 48px; }
.lesson-presentation .lp-button:hover:not(:disabled) { background: var(--lp-selected); }
.lesson-presentation .lp-button[aria-pressed="true"] { color: var(--lp-primary); background: var(--lp-selected); }
.lesson-presentation .lp-button:disabled { opacity: .45; cursor: default; }
.lesson-presentation .lp-button:focus-visible, .lesson-presentation .lp-number:focus-visible, .lesson-presentation .lp-image-button:focus-visible { outline: 3px solid var(--lp-primary); outline-offset: 3px; }
.lesson-presentation .lp-stage { min-width: 0; min-height: 0; overflow: hidden; overscroll-behavior: contain; touch-action: pan-y pinch-zoom; padding: clamp(16px, 3vw, 40px); }
.lesson-presentation .lp-stage:focus { outline: none; }
.lesson-presentation .lp-slide { --lp-gap: clamp(24px, 4vh, 40px); --lp-answer-gap: clamp(12px, 2vh, 20px); width: 100%; height: 100%; min-height: 0; display: grid; grid-template-columns: minmax(0, 1fr); grid-template-rows: var(--lp-rows); align-content: center; gap: 0; }
.lesson-presentation .lp-media { grid-column: 1; grid-row: var(--lp-row); min-width: 0; min-height: 0; width: 100%; display: flex; flex-direction: column; align-items: center; gap: 8px; overflow: auto; overscroll-behavior: contain; touch-action: pan-y pinch-zoom; }
.lesson-presentation .lp-image-frame { position: relative; display: flex; justify-content: center; align-items: center; flex: 1 1 auto; min-height: 0; width: 100%; height: 100%; }
.lesson-presentation .lp-image-drawing { position: absolute; overflow: hidden; pointer-events: none; }
.lesson-presentation .lp-image-drawing.is-drawing { pointer-events: auto; touch-action: none; cursor: url("/images/cursors/pen.svg") 4 28, default; }
.lesson-presentation .lp-image-button { display: flex; justify-content: center; align-items: center; width: 100%; height: 100%; min-height: 0; border: 0; padding: 0; background: transparent; color: inherit; cursor: zoom-in; border-radius: 4px; }
.lesson-presentation .lp-image { display: block; width: auto; height: auto; max-width: 100%; max-height: 100%; object-fit: contain; }
.lesson-presentation .lp-copy { display: contents; }
/* Each invisible region owns its overflow; revealing content leaves all tracks fixed. */
.lesson-presentation .lp-text-region { grid-column: 1; grid-row: var(--lp-row); justify-self: center; width: min(1100px, 100%); min-width: 0; min-height: 0; display: flex; flex-direction: column; overflow: auto; overscroll-behavior: contain; touch-action: pan-y pinch-zoom; scrollbar-width: thin; }
.lesson-presentation .lp-text-region.is-concealed { visibility: hidden; }
/* Reserve concealed text dimensions; the region remains invisible and inert. */
.lesson-presentation .lp-text-region.is-concealed > [hidden] { display: block !important; }
.lesson-presentation .lp-media.has-content[hidden] { display: flex !important; visibility: hidden; }
.lesson-presentation .lp-text-region:focus-visible { outline: 3px solid var(--lp-primary); outline-offset: -3px; }
.lesson-presentation .lp-question, .lesson-presentation .lp-answer { flex: 0 0 auto; width: 100%; margin: auto 0; text-align: center; white-space: pre-wrap; overflow-wrap: anywhere; }
.lesson-presentation .lp-question { font-size: clamp(24px, 3.4vw, 44px); line-height: 1.4; font-weight: 800; color: var(--lp-ink); }
.lesson-presentation .lp-answer { font-size: clamp(22px, 2.8vw, 36px); line-height: 1.45; font-weight: 800; color: var(--lp-answer); }
.lesson-presentation .lp-media-status { flex: 0 0 auto; margin: 0; padding: 4px 12px; color: var(--lp-muted); text-align: center; }
.lesson-presentation .lp-footer { position: relative; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 20px; padding: 8px max(20px, env(safe-area-inset-right)) max(8px, env(safe-area-inset-bottom)) max(20px, env(safe-area-inset-left)); background: var(--lp-surface); }
.lesson-presentation .lp-progress-track { position: absolute; inset: 0 0 auto; height: 3px; background: var(--lp-line); overflow: hidden; }
.lesson-presentation .lp-progress-fill { display: block; height: 100%; background: var(--lp-primary); }
.lesson-presentation .lp-navigation { gap: 0; }
.lesson-presentation .lp-progress { display: flex; align-items: center; gap: 4px; color: var(--lp-muted); font-size: 15px; font-variant-numeric: tabular-nums; }
.lesson-presentation .lp-counter { min-width: 64px; padding: 8px; font-variant-numeric: tabular-nums; font-size: 14px; }
.lesson-presentation .lp-navigation .lp-icon { font-size: 18px; }
.lesson-presentation .lp-navigation .lp-icon i { font-size: 18px; }
.lesson-presentation .lp-number { width: 65px; min-height: 48px; padding: 8px 4px 8px 8px; border: 1px solid var(--lp-line); border-radius: 8px; background: var(--lp-bg); color: var(--lp-ink); font: inherit; text-align: center; }
.lesson-presentation .lp-sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.lesson-presentation .lp-stage.is-dragging { user-select: none; cursor: grabbing; }
.lesson-presentation.is-zoomed .lp-stage { overflow: hidden; }
.lesson-presentation.is-zoomed .lp-slide { grid-template-rows: minmax(0, 1fr); }
.lesson-presentation.is-zoomed .lp-media { grid-row: 1 / -1; height: 100%; }
.lesson-presentation.is-zoomed .lp-image-frame { flex: 1 1 auto; min-height: 0; height: 100%; width: 100%; }
.lesson-presentation.is-zoomed .lp-image-button { width: 100%; height: 100%; min-height: 0; cursor: zoom-out; }
.lesson-presentation.is-zoomed .lp-image { width: 100%; height: 100%; max-height: 100%; }
.play-body.dark-mode .lesson-presentation { --lp-bg: #171522; --lp-surface: #211e30; --lp-ink: #f8f5ff; --lp-muted: #c2b8d7; --lp-primary: #c3a4ff; --lp-selected: #3b2c56; --lp-answer: #7ee5b4; --lp-line: #3b344d; color-scheme: dark; }
@media (max-width: 900px) {
  .lesson-presentation .lp-header { grid-template-columns: auto minmax(0, 1fr) auto auto; column-gap: 4px; row-gap: 0; }
  .lesson-presentation .lp-header-actions { display: contents; }
  .lesson-presentation .lp-back { grid-column: 1; grid-row: 1; }
  .lesson-presentation .lp-title { grid-column: 2; grid-row: 1; }
  .lesson-presentation .lp-annotation-tools { grid-column: 3; grid-row: 1; }
  .lesson-presentation .lp-view-actions { grid-column: 4; grid-row: 1; gap: 4px; margin-left: 0; }
  .lesson-presentation .lp-inline-palette { grid-column: 1 / -1; grid-row: 2; width: 100%; grid-template-rows: 0fr; transition: grid-template-rows 320ms cubic-bezier(.2,.7,.2,1), opacity 220ms ease, transform 320ms cubic-bezier(.2,.7,.2,1), visibility 0s 320ms; }
  .lesson-presentation .lp-inline-palette[aria-hidden="false"] { width: 100%; grid-template-rows: 1fr; }
  .lesson-presentation .lp-pen-controls, .lesson-presentation .zg-question-highlight__controls { overflow: hidden; padding: 0 4px; }
}
@media (max-width: 600px) {
  .lesson-presentation .lp-header { padding-inline: max(8px, env(safe-area-inset-left)) max(8px, env(safe-area-inset-right)); }
  .lesson-presentation .lp-back { width: 48px; padding: 10px; }
  .lesson-presentation .lp-back span { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .lesson-presentation .lp-title { font-size: 14px; }
  .lesson-presentation .lp-highlight-toggle { width: 48px; padding: 10px; }
  .lesson-presentation .lp-annotation-tools { width: 100px; flex-basis: 100px; }
  .lesson-presentation .lp-highlight-toggle span { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .lesson-presentation .lp-footer { justify-content: center; gap: 4px; padding-inline: max(8px, env(safe-area-inset-left)) max(8px, env(safe-area-inset-right)); }
  .lesson-presentation .lp-reveal { width: 100%; justify-content: center; gap: 4px; }
  .lesson-presentation .lp-reveal .lp-button { padding-inline: 12px; }
  .lesson-presentation .lp-navigation { margin: 0; }
  .lesson-presentation .lp-stage { padding: 16px; }
}
@media (max-width: 420px) {
  .lesson-presentation .lp-header .lp-button { min-width: 44px; min-height: 44px; }
  .lesson-presentation .lp-header .lp-icon { width: 44px; flex-basis: 44px; }
  .lesson-presentation .lp-annotation-tools { width: 88px; height: 44px; flex-basis: 88px; }
  .lesson-presentation .lp-drawing-tools { gap: 0; }
}
@media (max-height: 450px) and (min-width: 601px) {
  .lesson-presentation .lp-header, .lesson-presentation .lp-footer { padding-block: 4px; }
  .lesson-presentation .lp-stage { padding: 12px 24px; }
  .lesson-presentation .lp-slide { --lp-gap: 24px; }
}
@media (prefers-reduced-motion: reduce) {
  .lesson-presentation, .lesson-presentation * { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}