/* Audio Study Mode — sticky player and reading highlight.
   Browser TTS often stops if the tab is backgrounded or the screen locks. */

.audio-study-dock {
  position: sticky;
  bottom: 0;
  z-index: 40;
  margin-top: 1rem;
  max-width: 100%;
  overflow-x: hidden;
}

body.audio-study-ready .question-list {
  padding-bottom: 2rem;
}

body.audio-study-active .question-list {
  padding-bottom: 10rem;
}

.audio-study-panel {
  background: #111827;
  color: #e5e7eb;
  border-radius: 12px 12px 0 0;
  box-shadow: 0 -8px 24px rgba(15, 23, 42, 0.18);
  padding: 0.65rem 0.85rem 0.85rem;
  max-width: 100%;
  box-sizing: border-box;
}

.audio-study-mini-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.4rem;
  min-height: 44px;
}

.audio-mini-label,
.audio-mini-speed {
  font-weight: 700;
  font-size: 0.9rem;
}

.audio-mini-label {
  min-width: 7.5rem;
}

.audio-state {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0.1rem 0.5rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.audio-state[data-state="playing"] {
  background: rgba(22, 163, 74, 0.25);
}

.audio-state[data-state="paused"] {
  background: rgba(202, 138, 4, 0.28);
}

.audio-state[data-state="completed"] {
  background: rgba(37, 99, 235, 0.28);
}

.audio-study-full {
  display: none;
  padding-top: 0.55rem;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  margin-top: 0.45rem;
}

.audio-study-panel.is-expanded .audio-study-full {
  display: block;
}

.audio-study-head,
.audio-status-line {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 0.35rem;
}

.audio-reading-line {
  margin: 0 0 0.4rem;
  color: #93c5fd;
  font-size: 0.9rem;
}

.audio-progress {
  height: 6px;
  background: rgba(255, 255, 255, 0.12);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 0.65rem;
}

.audio-progress span {
  display: block;
  height: 100%;
  background: #60a5fa;
}

.audio-controls,
.audio-start-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.65rem;
}

.audio-icon-btn {
  min-width: 44px;
  min-height: 44px;
  border: 0;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  cursor: pointer;
  font-size: 1.05rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.3rem;
  padding: 0 0.65rem;
}

.audio-icon-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.audio-icon-btn:hover,
.audio-icon-btn:focus-visible {
  background: rgba(255, 255, 255, 0.18);
  outline: 2px solid #93c5fd;
  outline-offset: 1px;
}

.audio-icon-btn.audio-play {
  background: var(--header-blue, #1a73e8);
}

.audio-btn-text {
  font-size: 0.78rem;
  font-weight: 700;
}

.audio-study-mini-row .audio-btn-text {
  display: none;
}

.audio-settings,
.audio-toggles {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem 1rem;
  margin-bottom: 0.55rem;
  font-size: 0.88rem;
}

.audio-settings label,
.audio-toggles label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  min-width: 0;
  max-width: 100%;
}

.audio-settings select,
.audio-settings input[type="range"] {
  max-width: 100%;
  width: 100%;
  min-width: 0;
}

.audio-hint,
.audio-unsupported {
  margin: 0;
  font-size: 0.8rem;
  color: #9ca3af;
}

.audio-unsupported {
  color: #fca5a5;
}

.audio-setup .audio-fieldset {
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 10px;
  margin: 0 0 0.65rem;
  padding: 0.55rem 0.7rem;
}

.audio-setup legend {
  padding: 0 0.25rem;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.audio-setup .audio-fieldset label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin: 0.2rem 0.75rem 0.2rem 0;
}

.audio-chip {
  min-height: 36px;
  border: 0;
  border-radius: 999px;
  padding: 0.25rem 0.7rem;
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  cursor: pointer;
}

.audio-chip:hover,
.audio-chip:focus-visible {
  background: rgba(255, 255, 255, 0.18);
  outline: 2px solid #93c5fd;
}

.audio-presets,
.audio-range-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 0.65rem;
}

.audio-range-row input[type="number"] {
  width: 4.5rem;
  min-height: 36px;
}

.audio-resume-card {
  background: rgba(37, 99, 235, 0.2);
  border-radius: 10px;
  padding: 0.65rem 0.75rem;
  margin-bottom: 0.65rem;
}

.audio-think {
  text-align: center;
  padding: 0.4rem 0 0.2rem;
}

.audio-think strong {
  display: block;
  font-size: 2rem;
  line-height: 1.1;
  color: #fde68a;
}

.audio-stats {
  margin: 0 0 0.75rem;
  padding-left: 1.1rem;
}

.audio-progress-copy {
  margin: 0 0 0.4rem;
  font-size: 0.88rem;
}

.audio-setup {
  max-height: min(70vh, 640px);
  overflow-y: auto;
}

.q-card.audio-active {
  outline: 2px solid var(--header-blue);
  outline-offset: 2px;
}

.audio-reading {
  box-shadow: inset 3px 0 0 var(--header-blue);
  background: var(--soft);
}

.answer-panel.audio-reading,
.explanation.audio-reading,
.why-explanation.audio-reading {
  background: var(--soft);
}

@media (max-width: 1024px) {
  .audio-settings select,
  .audio-settings input[type="range"] {
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  .audio-study-panel.is-expanded .audio-controls .audio-btn-text {
    display: inline;
  }

  .audio-start-row .btn {
    flex: 1 1 calc(50% - 0.4rem);
  }
}

@media (max-width: 430px) {
  .audio-study-panel.is-mini .audio-mini-speed,
  .audio-study-mini-row .audio-mini-speed {
    display: none;
  }

  .audio-mini-label {
    min-width: 0;
    flex: 1 1 100%;
  }

  .audio-start-row .btn {
    flex: 1 1 100%;
  }

  .audio-settings,
  .audio-toggles {
    flex-direction: column;
    align-items: stretch;
  }

  .audio-settings label,
  .audio-toggles label {
    flex: 1 1 100%;
    flex-direction: column;
    align-items: stretch;
  }

  .audio-settings select,
  .audio-settings input[type="range"] {
    width: 100%;
  }
}

@media (max-width: 375px) {
  .audio-study-panel {
    padding: 0.55rem 0.65rem 0.75rem;
    border-radius: 10px 10px 0 0;
  }

  .audio-icon-btn {
    min-width: 44px;
    padding: 0 0.45rem;
  }
}

.audio-follow-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  user-select: none;
  margin: 0;
}

.audio-follow-switch input {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
}

.audio-follow-track {
  width: 42px;
  height: 24px;
  border-radius: 999px;
  background: #cbd5e1;
  position: relative;
  flex-shrink: 0;
  transition: background 0.15s ease;
}

.audio-follow-track::after {
  content: "";
  position: absolute;
  top: 3px;
  left: 3px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.25);
  transition: transform 0.15s ease;
}

.audio-follow-switch input:checked + .audio-follow-track {
  background: #0f766e;
}

.audio-follow-switch input:checked + .audio-follow-track::after {
  transform: translateX(18px);
}

.audio-follow-switch input:focus-visible + .audio-follow-track {
  outline: 2px solid #0f766e;
  outline-offset: 2px;
}

.audio-follow-copy {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
  color: var(--ink, #0f172a);
}

.audio-follow-copy strong {
  font-size: 0.85rem;
}

.audio-follow-copy span {
  font-size: 0.72rem;
  color: var(--muted, #64748b);
  font-weight: 600;
}

body.audio-follow-on .audio-follow-copy span {
  color: #0f766e;
}

.audio-q-btn {
  margin-left: auto;
  border: 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.18);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.65rem;
  cursor: pointer;
}

.audio-q-btn:hover {
  background: rgba(255, 255, 255, 0.3);
}

body.audio-follow-on .q-card.audio-active {
  outline: 2px solid #0f766e;
  outline-offset: 1px;
}