/* ============================================
   SESSION-SETTINGS.CSS
   Scoped arcade styles for Session Settings screen
   All colors via theme variables only — NO hex, rgb, hsl, or rgba values
   Hard edges, neon glows, Press Start 2P typography
   Touch targets ≥48px, full active/selected/disabled states
   ============================================ */

.session-settings-screen {
  position: relative;
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
  padding: var(--space-xl) var(--space-lg) calc(var(--space-xl) * 1.5);
  background-color: var(--color-background);
  color: var(--color-text);
  font-family: var(--font-body);
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.session-settings-content {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  padding-bottom: var(--space-xl);
  padding-top: var(--space-lg);
}

/* Push the Start button to the bottom of the content naturally */
.session-settings-content .action-bar {
  flex-shrink: 0;
  margin-top: auto;
  padding-top: var(--space-lg);
}


/* Screen Title — Arcade CRT style */
.session-settings-screen .screen-title {
  font-family: var(--font-display);
  font-size: var(--font-size-xl);
  color: var(--color-accent);
  text-shadow: 0 0 10px var(--color-accent);
  text-align: center;
  margin: 0 0 var(--space-md);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  line-height: 1.1;
}

.session-settings-screen .screen-subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  text-align: center;
  margin: 0 0 var(--space-xl);
  letter-spacing: 0.03em;
}

/* Segmented Control — Master Deck / Unit Study */
.segmented-control {
  display: flex;
  width: 100%;
  max-width: 420px;
  margin: 0 auto var(--space-xl);
  border: 3px solid var(--color-primary);
  border-radius: var(--border-radius-sm);
  overflow: hidden;
  box-shadow: 0 0 10px var(--color-primary);
  margin-bottom: 0;
  margin-top: var(--space-sm);
}

.segment-btn {
  flex: 1;
  padding: var(--space-md) var(--space-lg);
  min-height: 52px;
  background-color: transparent;
  border: none;
  color: var(--color-primary);
  font-family: var(--font-display);
  font-size: var(--font-size-md);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: background-color var(--transition-speed),
              color var(--transition-speed),
              box-shadow var(--transition-speed);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
}

.segment-btn + .segment-btn {
  border-left: 3px solid var(--color-primary);
}

.segment-btn.active,
.segment-btn.selected {
  background-color: var(--color-primary);
  color: var(--color-background);
  box-shadow: 0 0 14px var(--color-primary);
}

.segment-btn:active {
  transform: scale(0.985);
}

/* Unit Study Section */
#screen-session-settings .unit-study-section {
  margin-bottom: var(--space-xs);
  padding-top: 0;
}

.unit-study-section.hidden {
  display: none;
}

.unit-study-section .section-label {
  font-family: var(--font-display);
  font-size: var(--font-size-md);
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
  text-align: center;
}

/* 4-Column Unit Grid — Equal width tiles, hard edges */
.unit-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
  max-width: 520px;
  margin: 0 auto var(--space-lg);
}

.unit-tile {
  position: relative;
  aspect-ratio: 1 / 1.05;
  min-height: 76px;
  background-color: var(--color-surface);
  border: 2px solid var(--color-text-muted);
  border-radius: var(--border-radius-sm);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-sm) var(--space-xs);
  cursor: pointer;
  transition: transform var(--transition-speed),
              border-color var(--transition-speed),
              box-shadow var(--transition-speed);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  box-shadow: 0 0 4px var(--color-text-muted);
}

.unit-tile .unit-index {
  font-family: var(--font-display);
  font-size: var(--font-size-md);
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: var(--space-xs);
  white-space: nowrap;
  text-align: center;
}

.unit-tile .unit-count {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  text-align: center;
  letter-spacing: 0.02em;
}

.unit-tile.selected {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent), 0 0 16px var(--color-accent);
  transform: translateY(-1px);
}

.unit-tile:active {
  transform: scale(0.96);
  box-shadow: 0 0 12px var(--color-primary);
}

.unit-tile.locked {
  opacity: 0.45;
  pointer-events: none;
  border-style: dashed;
  border-color: var(--color-text-muted);
}

/* Session Length Slider */
.time-slider-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  max-width: 420px;
  margin: 0 auto;
}

.time-slider-value {
  font-family: var(--font-display);
  font-size: var(--font-size-lg);
  color: var(--color-accent);
  text-shadow: 0 0 8px var(--color-accent);
  letter-spacing: 0.05em;
}

.slider-range-labels {
  width: 100%;
  display: flex;
  justify-content: space-between;
  font-family: var(--font-display);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
}

/* Custom range input — hard edges, neon glow, ≥48px touch target */
.arcade-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 48px;         /* touch target height */
  background: transparent;
  cursor: pointer;
  margin: 0;
}

.arcade-slider:focus {
  outline: none;
}

/* Track */
.arcade-slider::-webkit-slider-runnable-track {
  height: 8px;
  background-color: var(--color-surface);
  border: 2px solid var(--color-secondary);
  border-radius: var(--border-radius-sm);
  box-shadow: 0 0 8px var(--color-secondary);
}

.arcade-slider::-moz-range-track {
  height: 8px;
  background-color: var(--color-surface);
  border: 2px solid var(--color-secondary);
  border-radius: var(--border-radius-sm);
  box-shadow: 0 0 8px var(--color-secondary);
}

/* Thumb — 32x32 hard-edge block, centered on the 8px track */
.arcade-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 32px;
  height: 32px;
  margin-top: -12px;
  background-color: var(--color-secondary);
  border: 2px solid var(--color-secondary);
  border-radius: var(--border-radius-sm);
  box-shadow: 0 0 12px var(--color-secondary), 0 0 24px var(--color-secondary);
  cursor: pointer;
  transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.arcade-slider::-webkit-slider-thumb:active {
  transform: scale(0.9);
  box-shadow: 0 0 20px var(--color-secondary), 0 0 36px var(--color-secondary);
}

.arcade-slider::-moz-range-thumb {
  width: 32px;
  height: 32px;
  background-color: var(--color-secondary);
  border: 2px solid var(--color-secondary);
  border-radius: var(--border-radius-sm);
  box-shadow: 0 0 12px var(--color-secondary), 0 0 24px var(--color-secondary);
  cursor: pointer;
}

.arcade-slider::-moz-range-thumb:active {
  transform: scale(0.9);
}

.arcade-slider:focus-visible::-webkit-slider-thumb,
.arcade-slider:focus-visible::-moz-range-thumb {
  animation: arcade-pulse 1.2s ease-in-out infinite;
}

/* ============================================
   READING SPEED SECTION
   Matches the style of .unit-study-section and .time-selector-section
   ============================================ */

.reading-speed-section {
  margin-bottom: var(--space-xl); 
  margin-top: 0;
}

.reading-speed-section .section-label {
  font-family: var(--font-display);
  font-size: var(--font-size-md);
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
  text-align: center;
}

.reading-speed-section .section-hint {
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  text-align: center;
  margin-top: var(--space-sm);
  letter-spacing: 0.02em;
  line-height: 1.4;
}

/* The segmented control itself reuses the global .segmented-control styles */
/* We just give this one a max-width to match the time selector */
#reading-speed-control {
  max-width: 420px;
  margin: 0 auto;
}

/* Inline Validation Error — positioned near controls */
.validation-error {
  color: var(--color-incorrect);
  font-size: var(--font-size-sm);
  font-family: var(--font-body);
  text-align: center;
  min-height: 22px;
  margin: var(--space-sm) 0 var(--space-md);
  padding: 0 var(--space-md);
  letter-spacing: 0.02em;
}

/* Start Button Container — pushed to bottom */
.start-button-container {
  margin-top: auto;
  padding-top: var(--space-lg);
  max-width: 420px;
  margin-left: auto;
  margin-right: auto;
  width: 100%;
}

.start-btn {
  width: 100%;
  min-height: 58px;
  padding: var(--space-lg) var(--space-xl);
  background-color: var(--color-primary);
  color: var(--color-background);
  border: 3px solid var(--color-primary);
  border-radius: var(--border-radius-sm);
  font-family: var(--font-display);
  font-size: var(--font-size-lg);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  cursor: pointer;
  box-shadow: 0 0 14px var(--color-primary), 0 0 28px var(--color-primary);
  transition: transform var(--transition-speed),
              box-shadow var(--transition-speed),
              background-color var(--transition-speed);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.start-btn:disabled,
.start-btn[disabled] {
  opacity: 0.32;
  pointer-events: none;
  box-shadow: none;
  background-color: var(--color-surface);
  border-color: var(--color-text-muted);
  color: var(--color-text-muted);
}

.start-btn:active:not(:disabled) {
  transform: scale(0.97);
  box-shadow: 0 0 22px var(--color-primary), 0 0 40px var(--color-primary);
}

/* Responsive refinements */
@media (min-width: 620px) {
  .session-settings-screen {
    max-width: 580px;
    margin: 0 auto;
    padding-top: calc(var(--space-xl) * 1.2);
  }

  .unit-grid {
    gap: var(--space-lg);
  }

  .time-selector {
    gap: var(--space-lg);
  }
}

/* ============================================
   DECK SELECTION ACCORDION
   (parity with Options theme accordion)
   ============================================ */

.deck-panel {
  margin-bottom: var(--space-xl);
}

.deck-panel .section-label {
  font-family: var(--font-display);
  font-size: var(--font-size-md);
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
  text-align: center;
}

.accordion-panel {
  /* header provides the edge */
}

.accordion-header {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  min-height: 56px;
  padding: var(--space-md) var(--space-lg);
  background: transparent;
  border: 2px solid var(--color-primary);
  border-radius: var(--border-radius-sm);
  color: var(--color-primary);
  font-family: var(--font-display);
  font-size: var(--font-size-md);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition:
    transform var(--transition-speed),
    box-shadow var(--transition-speed),
    background-color var(--transition-speed),
    color var(--transition-speed),
    border-color var(--transition-speed);
  user-select: none;
}

.accordion-header:hover {
  box-shadow: 0 0 10px var(--color-primary);
}

.accordion-header:active {
  transform: scale(0.98);
}

.accordion-header.open {
  background: var(--color-primary);
  color: var(--color-background);
  box-shadow:
    0 0 12px var(--color-primary),
    0 0 24px var(--color-primary);
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
  margin-bottom: 0;
}

.accordion-title {
  flex-shrink: 0;
  letter-spacing: 0.08em;
}

.accordion-current {
  flex: 1;
  text-align: right;
  font-size: var(--font-size-sm);
  opacity: 0.85;
  letter-spacing: 0.04em;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.accordion-header.open .accordion-current {
  opacity: 0.9;
}

.accordion-chevron {
  flex-shrink: 0;
  font-size: 12px;
  transition: transform var(--transition-speed);
  line-height: 1;
}

.accordion-header.open .accordion-chevron {
  transform: rotate(180deg);
}

.accordion-body {
  border: 2px solid var(--color-primary);
  border-top: none;
  border-radius: 0 0 var(--border-radius-sm) var(--border-radius-sm);
  padding: var(--space-md);
  background: var(--color-surface);
  box-shadow: 0 0 10px var(--color-primary);
}

.accordion-body[hidden] {
  display: none;
}

/* Deck option list inside accordion */
.deck-option-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.deck-option {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  width: 100%;
  min-height: 52px;
  padding: var(--space-md) var(--space-lg);
  background: transparent;
  border: 2px solid var(--color-text-muted);
  border-radius: var(--border-radius-sm);
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition:
    transform var(--transition-speed),
    border-color var(--transition-speed),
    box-shadow var(--transition-speed),
    background-color var(--transition-speed),
    color var(--transition-speed);
  user-select: none;
  text-align: left;
}

.deck-option:hover {
  border-color: var(--color-primary);
  box-shadow: 0 0 8px var(--color-primary);
}

.deck-option:active {
  transform: scale(0.98);
}

.deck-option.selected {
  border-color: var(--color-accent);
  background: var(--color-primary);
  color: var(--color-background);
  box-shadow:
    0 0 0 2px var(--color-accent),
    0 0 14px var(--color-accent);
}

.deck-option-label {
  flex: 1;
}

.deck-option-count {
  flex-shrink: 0;
  font-size: var(--font-size-sm);
  opacity: 0.8;
  letter-spacing: 0.02em;
}

.deck-option.selected .deck-option-count {
  opacity: 0.9;
}

/* Empty chapters message */
.empty-chapters {
  padding: var(--space-md);
  color: var(--color-text-muted);
  text-align: center;
  font-size: var(--font-size-sm);
}

/* Action bar — ensure vertical stack + centering */
.action-bar {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  margin-top: auto;
  padding-top: var(--space-lg);
}

.action-bar .btn-primary {
  max-width: 280px;
  width: auto;
}

/* Chapter config inherits unit-study-section spacing */
#chapter-config {
  margin-bottom: var(--space-xl);
}

#chapter-config.invalid .unit-grid {
  /* subtle feedback already handled by validation-error */
}