/* ============================================================
   SETTINGS SCREEN
   ============================================================ */

/* Header */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-2xl);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: var(--accent-gradient);
  border-radius: var(--radius-lg);
  font-size: 1.5rem;
  font-weight: 800;
  color: white;
  box-shadow: var(--shadow-glow-primary);
}

/* Sections */
.settings-section {
  margin-bottom: var(--space-xl);
  padding: var(--space-lg);
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
}

.settings-tile {
  margin-bottom: var(--space-xl);
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.settings-tile-section {
  padding: var(--space-lg);
}

.settings-tile-section + .settings-tile-section {
  border-top: 1px solid var(--border-subtle);
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.section-title {
  margin-bottom: var(--space-md);
}

.section-header .section-title {
  margin-bottom: 0;
}

.section-title-group {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.section-alert {
  color: var(--warning);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.8rem;
  font-weight: 600;
}

.section-alert[hidden] {
  display: none;
}

.select-all-group {
  display: flex;
  gap: var(--space-xs);
}

/* Mode Cards */
.mode-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
}

.mode-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-lg);
  background: var(--bg-tertiary);
  border: 2px solid transparent;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  font-family: inherit;
  color: var(--text-secondary);
}

@media (hover: hover) {
  .mode-card:hover {
    background: var(--bg-elevated);
    border-color: var(--border-medium);
    color: var(--text-primary);
    transform: translateY(-2px);
  }
}

.mode-card.selected {
  border-color: var(--accent-primary);
  background: hsla(265, 50%, 40%, 0.15);
  color: var(--text-primary);
  box-shadow: var(--shadow-glow-primary);
}

.mode-card-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  transition: all var(--transition-normal);
}

.mode-card.selected .mode-card-icon {
  background: var(--accent-primary-dim);
}

.mode-card h3 {
  font-size: 1.05rem;
  margin-top: var(--space-xs);
}

.mode-card p {
  font-size: 0.8rem;
  line-height: 1.4;
}

/* Input Mode Cards */
.input-mode-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
}

.input-mode-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  background: var(--bg-tertiary);
  border: 2px solid transparent;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  font-family: inherit;
  color: var(--text-secondary);
}

@media (hover: hover) {
  .input-mode-card:hover {
    background: var(--bg-elevated);
    border-color: var(--border-medium);
    color: var(--text-primary);
    transform: translateY(-2px);
  }
}

.input-mode-card.selected {
  border-color: var(--accent-primary);
  background: hsla(265, 50%, 40%, 0.15);
  color: var(--text-primary);
  box-shadow: var(--shadow-glow-primary);
}

.input-mode-card:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

.input-mode-card-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  transition: all var(--transition-normal);
}

.input-mode-card.selected .input-mode-card-icon {
  background: var(--accent-primary-dim);
}

.input-mode-card h3 {
  font-size: 0.95rem;
  margin-top: var(--space-xs);
}

.input-mode-card p {
  font-size: 0.78rem;
  line-height: 1.4;
}

/* Operation Toggles */
.operation-toggles {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-sm);
}

.op-toggle {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-md) var(--space-sm);
  background: var(--bg-tertiary);
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: inherit;
  color: var(--text-secondary);
}

@media (hover: hover) {
  .op-toggle:hover {
    background: var(--bg-elevated);
    color: var(--text-primary);
  }
}

.op-toggle.selected {
  border-color: var(--accent-secondary);
  background: hsla(190, 50%, 35%, 0.15);
  color: var(--text-primary);
}

.op-symbol {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.5rem;
  font-weight: 700;
}

.op-label {
  font-size: 0.75rem;
}

/* Direction Toggles */
.direction-toggles {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--space-sm);
}

.dir-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: var(--bg-tertiary);
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
}

@media (hover: hover) {
  .dir-toggle:hover {
    background: var(--bg-elevated);
    color: var(--text-primary);
  }
}

.dir-toggle.selected {
  border-color: var(--accent-secondary);
  background: hsla(190, 50%, 35%, 0.15);
  color: var(--text-primary);
}

.dir-icon {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.2rem;
  font-weight: 700;
  min-width: 32px;
  width: auto;
  padding: 0 4px;
  white-space: nowrap;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
}

.dir-toggle.selected .dir-icon {
  background: var(--accent-secondary-dim);
}

/* Boundaries */
#boundaries-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-sm);
}

.boundary-card {
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  border: 1px solid var(--border-subtle);
}

.boundary-card-header {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  margin-bottom: var(--space-md);
}

.boundary-info-icon {
  position: absolute;
  right: 0;
  background: none;
  border: none;
  padding: 2px;
  cursor: default;
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.section-info-icon {
  background: none;
  border: none;
  padding: 2px;
  cursor: default;
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.boundary-info-icon[data-tooltip]::after,
.section-info-icon[data-tooltip]::after {
  white-space: normal;
  width: 220px;
  text-align: left;
  top: auto;
  bottom: calc(100% + 6px);
  font-weight: 400;
}

/* boundary icon is on the right edge — tooltip extends leftward */
.boundary-info-icon[data-tooltip]::after {
  left: auto;
  right: 0;
  transform: none;
}

/* section icons are on the left — tooltip extends rightward */
.section-info-icon[data-tooltip]::after {
  left: 0;
  right: auto;
  transform: none;
}

.boundary-op-badges {
  display: flex;
  gap: var(--space-xs);
}

.boundary-op-badge {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.3rem;
  font-weight: 700;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
}

.boundary-card-header h4 {
  flex: 1;
  font-size: 0.9rem;
}


/* Dual Range Slider */
.dual-range-container {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-top: var(--space-md);
  margin-bottom: var(--space-sm);
}

.dual-range-slider {
  position: relative;
  flex: 1;
  height: 6px;
  background: var(--bg-secondary);
  border-radius: 3px;
  margin: 0 var(--space-xs);
}

.dual-range-slider .dual-slider-track {
  position: absolute;
  top: 0;
  bottom: 0;
  background: var(--accent-primary);
  border-radius: 3px;
  z-index: 1;
}

.dual-range-slider input[type="range"] {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 100%;
  -webkit-appearance: none;
  background: transparent;
  pointer-events: none;
  z-index: 2;
  margin: 0;
  left: 0;
}

.dual-range-slider input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-primary);
  cursor: grab;
  pointer-events: auto;
  position: relative;
  z-index: 3;
  box-shadow: var(--shadow-sm);
}

.dual-range-slider input[type="range"]:active::-webkit-slider-thumb {
  cursor: grabbing;
  transform: scale(1.1);
}

.dual-range-slider input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-primary);
  cursor: grab;
  pointer-events: auto;
  position: relative;
  z-index: 3;
  box-shadow: var(--shadow-sm);
  border: none;
}

.dual-range-slider input[type="range"]:active::-moz-range-thumb {
  cursor: grabbing;
  transform: scale(1.1);
}

.dual-range-container .boundary-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  text-align: center;
  background: var(--bg-secondary);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  width: 50px;
  min-width: 0;
}

/* Value Mode Toggle (Range / Specific) */
.value-mode-toggle {
  display: flex;
  gap: 2px;
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  padding: 2px;
  margin-bottom: var(--space-md);
}

.vmt-btn {
  flex: 1;
  padding: var(--space-xs) var(--space-sm);
  border: none;
  border-radius: calc(var(--radius-sm) - 1px);
  background: transparent;
  color: var(--text-tertiary);
  font-family: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

@media (hover: hover) {
  .vmt-btn:hover {
    color: var(--text-secondary);
  }
}

.vmt-btn.active {
  background: var(--accent-primary-dim);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
}

/* Specific Values Grid */
.boundary-specific-content {
  margin-top: var(--space-xs);
}

.specific-actions {
  display: flex;
  gap: var(--space-xs);
  margin-bottom: var(--space-sm);
}

.specific-values-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(42px, 1fr));
  gap: var(--space-xs);
}

.specific-chip {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-xs) var(--space-xs);
  min-height: 36px;
  background: var(--bg-secondary);
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-tertiary);
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
}

@media (hover: hover) {
  .specific-chip:hover {
    background: var(--bg-elevated);
    color: var(--text-secondary);
    border-color: var(--border-medium);
  }
}

.specific-chip.selected {
  background: hsla(190, 50%, 35%, 0.2);
  border-color: var(--accent-secondary);
  color: var(--text-primary);
}

@media (hover: hover) {
  .specific-chip.selected:hover {
    background: hsla(190, 50%, 35%, 0.3);
  }
}

/* Inline mode settings row (Questions + Time per Q) */
.mode-settings-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  justify-items: center;
}

.mode-setting-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.mode-setting-item label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 500;
  text-align: center;
}

/* Settings Grid */
.settings-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.setting-item label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: var(--space-sm);
}

.stepper-group {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.stepper-input {
  width: 64px;
  text-align: center;
  padding: var(--space-sm);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 1rem;
  font-weight: 600;
}

.stepper-input:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 2px hsla(265, 90%, 65%, 0.2);
}

/* Start button */
.start-section {
  text-align: center;
  padding-top: var(--space-lg);
}

.btn-start {
  background: var(--accent-gradient);
  color: white;
  padding: var(--space-md) var(--space-3xl);
  font-size: 1.2rem;
  font-weight: 700;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-glow-primary);
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: var(--space-md);
  transition: all var(--transition-normal);
  font-family: inherit;
}

@media (hover: hover) {
  .btn-start:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 0 40px hsla(265, 90%, 65%, 0.5);
  }
}

.btn-start:active {
  transform: translateY(0) scale(0.98);
}

.btn-start:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none;
}

/* Difficulty Cards (BTC) */
.difficulty-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.difficulty-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-lg) var(--space-md);
  background: var(--bg-tertiary);
  border: 2px solid transparent;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  font-family: inherit;
  color: var(--text-secondary);
}

@media (hover: hover) {
  .difficulty-card:hover {
    background: var(--bg-elevated);
    border-color: var(--border-medium);
    color: var(--text-primary);
    transform: translateY(-2px);
  }
}

.difficulty-card.selected {
  color: var(--text-primary);
}

.difficulty-badge {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-md);
}

.difficulty-badge.easy {
  background: hsla(145, 70%, 50%, 0.15);
  color: var(--success);
}

.difficulty-badge.normal {
  background: hsla(40, 90%, 60%, 0.15);
  color: var(--warning);
}

.difficulty-badge.hard {
  background: hsla(0, 80%, 60%, 0.15);
  color: var(--error);
}

.difficulty-card.selected[data-difficulty="easy"] {
  border-color: var(--success);
  background: hsla(145, 50%, 30%, 0.12);
  box-shadow: var(--shadow-glow-success);
}

.difficulty-card.selected[data-difficulty="normal"] {
  border-color: var(--warning);
  background: hsla(40, 50%, 30%, 0.12);
  box-shadow: 0 0 20px hsla(40, 90%, 60%, 0.25);
}

.difficulty-card.selected[data-difficulty="hard"] {
  border-color: var(--error);
  background: hsla(0, 50%, 30%, 0.12);
  box-shadow: var(--shadow-glow-error);
}

.difficulty-desc {
  font-size: 0.8rem;
  line-height: 1.3;
}

.difficulty-target {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */

@media (max-width: 600px) {
  .mode-cards,
  .input-mode-cards {
    grid-template-columns: 1fr;
  }

  .mode-settings-row {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }

  .operation-toggles {
    grid-template-columns: repeat(2, 1fr);
  }

  .direction-toggles {
    grid-template-columns: 1fr 1fr;
  }

  #boundaries-container {
    grid-template-columns: 1fr;
  }

  .boundary-row {
    grid-template-columns: 60px 1fr 60px;
  }

  .stepper-group {
    flex-wrap: nowrap;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .direction-toggles {
    grid-template-columns: 1fr;
  }
}