/* A narrated lesson (lessons/show, lesson_player_controller.js; design: Claude Design "Lesson Player"): a header,
   progress by slide (questions as dots), the stage with the line being read highlighted, captions, and controls.
   data-state on the player: start, playing, paused, waiting, loading, finished. .is-classroom: the classroom view. */
.lesson-player { max-width: 1100px; width: 100%; margin: 0 auto; gap: 0; background: var(--paper); color: var(--ink);
                 border: 1px solid var(--line); border-radius: 14px; overflow: hidden; }

/* Header and progress */
.lesson-player__bar { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 12px 24px;
                      border-bottom: 1px solid var(--line); }
.lesson-player__back, .lesson-player__room-btn { display: inline-flex; align-items: center; gap: 8px; min-height: 44px; padding: 0 14px;
  border: 1px solid var(--line); border-radius: 999px; background: transparent; color: var(--ink); font-size: 14px; font-weight: 600;
  flex-shrink: 0; text-decoration: none; }
.lesson-player__back:hover, .lesson-player__room-btn:hover { background: var(--sand); color: var(--ink); text-decoration: none; }
.lesson-player__title { flex: 1; min-width: 0; display: flex; align-items: center; justify-content: center; gap: 8px; }
.lesson-player__name { font-size: 15px; font-weight: 700; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.lesson-player__level { background: var(--sand); border-radius: 6px; padding: 2px 8px; font-size: 12px; font-weight: 700; flex-shrink: 0; }
.lesson-player__progress { display: flex; align-items: center; gap: 12px; padding: 12px 24px 0; }
.lesson-player__count { font-size: 13px; font-weight: 700; white-space: nowrap; }
.lesson-player__type { font-size: 12px; color: var(--text-muted); white-space: nowrap; }
.lesson-player__track { flex: 1; display: flex; align-items: center; gap: 3px; }
.lesson-player__seg { flex: 1; height: 5px; border-radius: 3px; background: var(--line); }
.lesson-player__seg--check { flex: 0 0 auto; width: 9px; height: 9px; border-radius: 50%; background: var(--card);
                             box-shadow: inset 0 0 0 1.5px var(--text-muted); }
.lesson-player__seg.is-done { background: var(--ink); box-shadow: none; }
.lesson-player__seg.is-current { background: var(--clay); box-shadow: none; }

/* Stage */
.lesson-player__main { flex: 1; min-height: 0; padding: 16px 24px 18px; display: flex; flex-direction: column; gap: 14px; }
.lesson-player__stage { position: relative; flex: 1; min-height: 400px; width: 100%; max-width: 900px; margin: 0 auto; background: var(--card);
  border: 1px solid var(--line); border-radius: 20px; padding: 32px 44px; display: flex; flex-direction: column; justify-content: center; }
.lesson-slide { display: flex; flex-direction: column; gap: 14px; animation: lesson-in .24s ease-out both; }
@keyframes lesson-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
@keyframes lesson-spin { to { transform: rotate(360deg); } }

/* The line being read: a soft clay band with a bar on its leading edge. */
.lesson-slide__band { padding: 8px 14px; border-radius: 12px; border-inline-start: 3px solid transparent; transition: background-color .2s; }
.lesson-slide__band.is-reading { background: var(--clay-soft); border-inline-start-color: var(--clay); }

.lesson-slide__eyebrow { font-size: 13px; letter-spacing: 1.4px; text-transform: uppercase; color: var(--text-muted); font-weight: 700; }
.lesson-slide__eyebrow.lesson-slide__band { align-self: flex-start; padding: 4px 10px; border-radius: 8px; }
.lesson-slide__eyebrow--clay { color: var(--clay); }
:lang(ar) .lesson-slide__eyebrow, :lang(ar) .lesson-slide__turn { letter-spacing: 0; }
.lesson-slide__inline { font-size: 1.2em; line-height: 1.5; }

.lesson-slide__title { margin: 0; font-family: var(--font-serif); font-weight: 400; font-size: 52px; line-height: 1.15; text-wrap: balance; }
.lesson-slide--title .lesson-slide__title { align-self: flex-start; padding: 0 14px; margin-inline-start: -14px; }
.lesson-slide__meta { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; font-size: 14px; color: var(--text-muted); }
.lesson-slide__level { background: var(--ink); color: var(--paper); border-radius: 6px; padding: 3px 10px; font-weight: 700; }

.lesson-slide__para { margin: 0; font-size: 21px; line-height: 1.6; text-wrap: pretty; }

.lesson-slide__table-wrap { max-width: 100%; overflow-x: auto; }
.lesson-slide__table { width: 100%; border-collapse: separate; border-spacing: 0 3px; }
.lesson-slide__table th { text-align: start; padding: 8px 14px; font-size: 13px; letter-spacing: 1.4px; text-transform: uppercase; color: var(--text-muted);
                          border-bottom: 1px solid var(--line); }
.lesson-slide__table td { padding: 8px 14px; font-size: 17px; line-height: 1.6; text-align: start; }
.lesson-slide__cell-taught { font-size: 26px; }

.lesson-slide__sentence { display: flex; flex-direction: column; gap: 2px; border-radius: 14px; }
.lesson-slide__sentence-text { font-size: 50px; line-height: 1.6; text-align: start; }
:lang(ar) > .lesson-slide__sentence-text, :lang(fa) > .lesson-slide__sentence-text { line-height: 2; }
.lesson-slide__reading { font-family: var(--font-sans); font-size: 19px; color: var(--text-muted); letter-spacing: .3px; }
.lesson-slide__meaning { margin: 0; font-family: var(--font-serif); font-size: 28px; line-height: 1.35; }
.lesson-slide__note { margin: 0; font-size: 17px; line-height: 1.55; color: var(--text-muted); }
.lesson-slide__note .lesson-slide__inline { color: var(--ink); }

/* Questions */
.lesson-slide__check-head { display: flex; justify-content: space-between; align-items: center; gap: 10px; flex-wrap: wrap; }
.lesson-slide__turn { display: flex; align-items: center; gap: 8px; font-size: 13px; letter-spacing: 1.4px; text-transform: uppercase; color: var(--clay); font-weight: 700; }
.lesson-slide__turn::before { content: ""; width: 10px; height: 10px; border-radius: 50%; background: var(--clay); }
.lesson-slide__waiting { display: none; font-size: 13px; color: var(--text-muted); font-weight: 600; }
.lesson-player[data-state="waiting"] .lesson-slide__waiting { display: inline; }
.lesson-slide__ask { font-size: 21px; line-height: 1.45; font-weight: 600; }
.lesson-slide__prompt { margin: 0; font-size: 24px; line-height: 1.5; }
.lesson-slide__gap-line { font-size: 42px; line-height: 1.6; text-align: start; }
:lang(ar).lesson-slide__gap-line, :lang(fa).lesson-slide__gap-line { line-height: 2; }
.lesson-slide__gap { display: inline-block; min-width: 110px; margin: 0 6px; padding: 0 8px; border-bottom: 3px dashed var(--clay); border-radius: 8px 8px 0 0; text-align: center; }
.lesson-slide__gap.is-filled { border-bottom-style: solid; border-bottom-color: var(--green); background: var(--green-soft); }
.lesson-slide__target { padding: 0 6px; border-radius: 8px; background: var(--peach); font-weight: 700; }
.lesson-slide__choices { display: grid; grid-template-columns: repeat(var(--choices, 4), minmax(0, 1fr)); gap: 10px; }
.lesson-slide__caption { margin: 0; font-size: 17px; line-height: 1.5; color: var(--text-muted); }
.lesson-slide__choice { position: relative; display: flex; align-items: center; justify-content: center; gap: 10px; min-height: 64px; padding: 6px 14px;
  background: var(--card); color: var(--ink); border: 1.5px solid var(--line); border-radius: 14px; font-size: 28px; line-height: 1.5; cursor: pointer; }
.lesson-slide__choice:hover:not([aria-disabled="true"]) { border-color: var(--ink); }
.lesson-slide__choice[aria-disabled="true"] { cursor: default; }
.lesson-slide__choice.is-right { background: var(--green-soft); border-color: var(--green); }
.lesson-slide__choice.is-wrong { background: var(--clay-soft); border-color: var(--clay); }
.lesson-slide__choice-key { position: absolute; top: 6px; inset-inline-start: 10px; font-family: var(--font-sans); font-size: 11px; color: var(--text-muted); }
.lesson-slide__choice-text--site { font-size: 22px; }
.lesson-slide__choice-tag { font-family: var(--font-sans); font-size: 13px; font-weight: 700; }
.lesson-slide__choice-tag:empty { display: none; }
.lesson-slide__feedback { display: flex; flex-direction: column; gap: 4px; padding: 12px 16px; border-radius: 14px; font-size: 17px; line-height: 1.55; }
.lesson-slide__feedback strong { font-size: 16px; }
.lesson-slide__feedback.is-right { background: var(--green-soft); }
.lesson-slide__feedback.is-right strong { color: var(--green); }
.lesson-slide__feedback.is-wrong { background: var(--sand); }
.lesson-slide__feedback.is-reading { background: var(--green-soft); }
.lesson-slide__feedback.is-wrong.is-reading { background: var(--sand); }

/* Tips and summary */
.lesson-slide__tips { margin: 0; padding: 0; list-style: none; display: flex; flex-direction: column; gap: 6px; }
.lesson-slide__tips li { display: flex; gap: 12px; align-items: baseline; font-size: 21px; line-height: 1.5; }
.lesson-slide__tip-number { font-family: var(--font-serif); font-size: 1.2em; color: var(--clay); min-width: 18px; }
.lesson-slide__summary-title { margin: 0; font-family: var(--font-serif); font-weight: 400; font-size: 40px; line-height: 1.15; }
.lesson-slide__score { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.lesson-slide__score strong { font-size: 22px; }
.lesson-slide__dots { display: flex; gap: 6px; }
.lesson-slide__dot { width: 28px; height: 28px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 14px; font-weight: 700;
                     border: 1.5px solid; }
.lesson-slide__dot.is-right { background: var(--green-soft); color: var(--green); border-color: var(--green); }
.lesson-slide__dot.is-wrong { background: var(--clay-soft); color: var(--clay); border-color: var(--clay); }
.lesson-slide__closing { margin: 0; font-size: 21px; line-height: 1.55; color: var(--text-muted); }
.lesson-slide__actions { display: flex; gap: 10px; flex-wrap: wrap; }
.lesson-slide__practice, .lesson-slide__again { display: inline-flex; align-items: center; min-height: 50px; padding: 10px 22px; border-radius: 999px;
  font-size: 16px; font-weight: 600; line-height: 1.25; text-decoration: none; }
.lesson-slide__practice { background: var(--ink); color: var(--paper); border: none; }
.lesson-slide__practice:hover { color: var(--paper); text-decoration: none; opacity: .9; }
.lesson-slide__again { background: transparent; color: var(--ink); border: 1.5px solid var(--ink); cursor: pointer; }

/* Start screen, paused chip */
.lesson-player__start { position: absolute; inset: 0; border-radius: inherit; background: var(--card); display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 14px; padding: 24px; text-align: center; z-index: 2; }
.lesson-player__start-btn { display: flex; align-items: center; gap: 12px; margin-top: 6px; min-height: 60px; padding: 0 30px 0 24px; border: none; border-radius: 999px;
  background: var(--ink); color: var(--paper); font-size: 18px; font-weight: 700; outline: 3px solid var(--clay-soft); outline-offset: 3px; cursor: pointer; }
.lesson-player__sound-hint { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--text-muted); }
.lesson-player__paused { display: none; position: absolute; top: 14px; inset-inline-end: 14px; align-items: center; gap: 6px; background: var(--sand);
  border-radius: 999px; padding: 4px 12px; font-size: 13px; font-weight: 600; }
.lesson-player[data-state="paused"] .lesson-player__paused { display: flex; }

/* Captions and notes under the stage */
.lesson-player__caption, .lesson-player__unavailable, .lesson-player__captions-off { width: 100%; max-width: 900px; margin: 0 auto; }
.lesson-player__caption { display: flex; align-items: flex-start; gap: 12px; min-height: 58px; padding: 14px 18px; border-radius: 14px; background: var(--ink); color: var(--paper); }
.lesson-player__caption[hidden], .lesson-player__unavailable[hidden], .lesson-player__captions-off[hidden] { display: none; }
.lesson-player__caption-icon { width: 20px; height: 20px; flex-shrink: 0; margin-top: 4px; fill: none; stroke: var(--peach); stroke-width: 1.8; stroke-linecap: round; }
[dir="rtl"] .lesson-player__caption-icon, [dir="rtl"] .lesson-player__flip, [dir="rtl"] .lesson-player__back > span { transform: scaleX(-1); }
.lesson-player__caption-text { margin: 0; flex: 1; font-size: 18px; line-height: 1.55; text-wrap: pretty; }
.lesson-player__caption .lesson-slide__inline { font-size: 1.15em; }
.lesson-player[data-state="loading"] .lesson-player__caption-text { color: var(--sand); }
.lesson-player__unavailable { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; background: var(--sand); border-radius: 12px; padding: 8px 14px;
  font-size: 14px; line-height: 1.45; }
.lesson-player__unavailable svg { flex-shrink: 0; }
.lesson-player__unavailable span { flex: 1; min-width: 200px; }
.lesson-player__unavailable button { background: none; border: none; color: var(--clay); font-size: 14px; font-weight: 600; min-height: 40px; text-decoration: underline; cursor: pointer; }
.lesson-player__captions-off { margin-top: 0; font-size: 13px; color: var(--text-muted); text-align: center; }
.lesson-player__spinner { display: inline-block; width: 24px; height: 24px; border-radius: 50%; border: 2.5px solid rgba(255, 255, 255, .35);
  border-top-color: var(--paper); animation: lesson-spin .9s linear infinite; }
.lesson-player__spinner--small { width: 18px; height: 18px; margin-top: 3px; flex-shrink: 0; border-width: 2px; }

/* Controls */
.lesson-player__controls { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px 14px; padding: 12px 24px;
  border-top: 1px solid var(--line); background: var(--card); }
.lesson-player__toggles { flex: 1; display: flex; gap: 8px; }
.lesson-player__chip { display: flex; align-items: center; gap: 6px; min-height: 44px; padding: 0 14px; border: 1.5px solid var(--ink); border-radius: 999px;
  background: transparent; color: var(--ink); font-size: 14px; font-weight: 700; cursor: pointer; }
.lesson-player__chip[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.lesson-player__chip-light { font-weight: 500; }
.lesson-player__cc { border: 1.5px solid currentColor; border-radius: 4px; padding: 0 3px; font-size: 11px; line-height: 1.3; }
.lesson-player__transport { flex: 0 0 auto; display: flex; align-items: center; justify-content: center; gap: 12px; }
.lesson-player__round { width: 52px; height: 52px; border-radius: 50%; background: transparent; border: 1.5px solid var(--line); color: var(--ink);
  display: flex; align-items: center; justify-content: center; cursor: pointer; }
.lesson-player__round:hover:not(:disabled) { border-color: var(--ink); }
.lesson-player__round:disabled { opacity: .4; cursor: default; }
.lesson-player__play { width: 64px; height: 64px; border-radius: 50%; background: var(--ink); border: none; color: var(--paper); display: flex;
  align-items: center; justify-content: center; cursor: pointer; }
.lesson-player__play[aria-disabled="true"] { background: var(--text-muted); cursor: default; }
.lesson-player__play > * { display: none; }
.lesson-player[data-state="start"] .lesson-player__icon-play, .lesson-player[data-state="paused"] .lesson-player__icon-play,
.lesson-player[data-state="waiting"] .lesson-player__icon-play, .lesson-player[data-state="playing"] .lesson-player__icon-pause,
.lesson-player[data-state="loading"] .lesson-player__icon-spin, .lesson-player[data-state="finished"] .lesson-player__icon-replay { display: block; }
.lesson-player__keys { flex: 1; text-align: end; font-size: 12px; color: var(--text-muted); }
[dir="rtl"] .lesson-player__keys { visibility: hidden; }

/* Classroom view: large, for projecting; controls tucked away until the mouse moves. */
.lesson-player__room, .lesson-player__room-exit { display: none; }
.lesson-player.is-classroom { position: fixed; inset: 0; z-index: 1000; max-width: none; height: 100vh; border: none; border-radius: 0; }
html.lesson-classroom-open { overflow: hidden; }
.is-classroom .lesson-player__bar, .is-classroom .lesson-player__progress { display: none; }
.is-classroom .lesson-player__main { padding: 64px 72px 104px; gap: 18px; overflow: hidden; } /* room for the controls when they show */
.is-classroom .lesson-player__stage { flex: 1 1 auto; max-width: 1100px; border-radius: 24px; padding: 40px 56px; min-height: 0; overflow: auto; justify-content: safe center; }
.is-classroom .lesson-player__caption, .is-classroom .lesson-player__unavailable { flex-shrink: 0; }
.is-classroom.is-awake .lesson-player__room-hint { visibility: hidden; }
.is-classroom .lesson-player__caption, .is-classroom .lesson-player__unavailable { max-width: 1100px; }
.is-classroom .lesson-slide { gap: 22px; }
.is-classroom .lesson-slide__title { font-size: 76px; }
.is-classroom .lesson-slide__para, .is-classroom .lesson-slide__tips li, .is-classroom .lesson-slide__closing, .is-classroom .lesson-slide__ask { font-size: 32px; }
.is-classroom .lesson-slide__sentence-text { font-size: 76px; }
.is-classroom .lesson-slide__reading { font-size: 26px; }
.is-classroom .lesson-slide__meaning { font-size: 40px; }
.is-classroom .lesson-slide__note, .is-classroom .lesson-slide__feedback { font-size: 26px; }
.is-classroom .lesson-slide__gap-line { font-size: 56px; }
.is-classroom .lesson-player__caption { padding: 18px 24px; }
.is-classroom .lesson-player__caption-text { font-size: 28px; }
.is-classroom .lesson-player__controls { position: absolute; left: 0; right: 0; bottom: 0; opacity: 0; pointer-events: none; transition: opacity .2s; }
.is-classroom.is-awake .lesson-player__controls { opacity: 1; pointer-events: auto; }
.is-classroom .lesson-player__room { display: block; }
.lesson-player__room-count { position: absolute; top: 26px; inset-inline-end: 230px; font-size: 14px; color: var(--text-muted); }
.lesson-player__room-line { position: absolute; left: 0; right: 0; bottom: 0; height: 5px; background: var(--line); }
.lesson-player__room-line span { display: block; height: 100%; background: var(--clay); }
[dir="rtl"] .lesson-player__room-line span { margin-inline-start: 0; }
.lesson-player__room-hint { position: absolute; bottom: 14px; inset-inline-start: 22px; font-size: 13px; color: var(--text-muted); }
.is-classroom .lesson-player__room-exit { display: block; position: absolute; top: 18px; inset-inline-end: 22px; min-height: 40px; padding: 0 14px;
  background: var(--card); border: 1px solid var(--line); border-radius: 999px; font-size: 13px; font-weight: 600; color: var(--ink); cursor: pointer; }

/* The grammar page's button to the player */
.grammar__play { margin-top: 8px; display: inline-flex; gap: 6px; align-items: center; }

@media (max-width: 760px) {
  .lesson-player { border-radius: 0; border-inline: none; }
  .lesson-player__bar { padding: 10px 12px; }
  .lesson-player__room-btn, .lesson-player__keys { display: none; }
  .lesson-player__progress { padding: 10px 16px 0; }
  .lesson-player__main { padding: 12px 12px 14px; }
  .lesson-player__stage { min-height: 360px; padding: 20px 16px; }
  .lesson-slide__title { font-size: 34px; }
  .lesson-slide__para, .lesson-slide__tips li, .lesson-slide__ask { font-size: 17px; }
  .lesson-slide__sentence-text { font-size: 34px; }
  .lesson-slide__reading { font-size: 16px; }
  .lesson-slide__meaning { font-size: 22px; }
  .lesson-slide__note, .lesson-slide__feedback { font-size: 15px; }
  .lesson-slide__summary-title { font-size: 30px; }
  .lesson-slide__gap-line { font-size: 30px; }
  .lesson-slide__gap { min-width: 70px; }
  .lesson-slide__choices { grid-template-columns: repeat(min(var(--choices, 4), 2), minmax(0, 1fr)); }
  .lesson-slide__choice { min-height: 58px; font-size: 24px; }
  .lesson-slide__cell-taught { font-size: 22px; }
  .lesson-slide__table td { padding: 6px 10px; font-size: 15px; }
  .lesson-player__caption { min-height: 64px; padding: 12px 14px; }
  .lesson-player__caption-text { font-size: 16px; }
  .lesson-player__controls { padding: 12px 14px 18px; }
  .lesson-player__transport { order: 1; flex: 1 1 100%; }
  .lesson-player__toggles { order: 2; flex: 1 1 100%; justify-content: center; }
}

@media (prefers-reduced-motion: reduce) {
  .lesson-slide { animation: none; }
  .lesson-slide__band { transition: none; }
  .lesson-player__spinner { animation-duration: 2.4s; }
}