/* ==========================================================================
   options.css
   Scoped stylesheet for the Options screen (theme accordion + batch + update)
   Korean Vocabulary PWA — Arcade CRT aesthetic (late 80s/early 90s)
   
   RULES ENFORCED:
   - ZERO hardcoded hex, rgb(), rgba(), hsl() anywhere. All color via var(--color-*)
   - Hard edges only (border-radius via tokens, max 4px)
   - Neon glows via layered box-shadow + var(--color-*) only
   - Press Start 2P for all UI typography
   - Noto Sans KR available for any future Korean labels
   - Touch targets ≥48px
   - .selected + :active states with scale + glow
   - Live theme preview: selecting a theme instantly updates entire UI via :root vars
   - Back button at bottom (matches session-settings / flashcard-options pattern)
   ========================================================================== */

#screen-options,
.screen.options {
  position: relative;
  min-height: 100dvh;
  width: 100%;
  padding: var(--space-lg);
  padding-bottom: calc(var(--space-xl) + env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
  background: var(--color-background);
  color: var(--color-text);
  font-family: var(--font-body);
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

/* Fix mobile cutoff — make content scrollable */
.options-container {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

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

/* ---------- Header (Title only — back is at bottom) ---------- */
.screen-header {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-md);
  border-bottom: 2px solid var(--color-text-muted);
  width: 100%;
}

.header-center {
  flex: 1;
  text-align: center;
}

.screen-title {
  font-family: var(--font-display);
  font-size: var(--font-size-xl);
  font-weight: 400;
  color: var(--color-accent);
  text-shadow: 
    0 0 6px var(--color-accent),
    0 0 12px var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin: 0;
  line-height: 1.1;
}

/* ---------- Shared Panel Layout ---------- */
.theme-panel,
.batch-panel,
.update-panel {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-text-muted);
}

.panel-header {
  margin-bottom: var(--space-lg);
  text-align: center;
}

.panel-title {
  font-family: var(--font-display);
  font-size: var(--font-size-lg);
  color: var(--color-secondary);
  text-shadow: 0 0 6px var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0 0 var(--space-sm) 0;
}

.panel-desc {
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin: 0 0 var(--space-md) 0;
  letter-spacing: 0.02em;
  text-align: center;
}

.panel-desc strong {
  color: var(--color-correct);
}

/* ---------- Theme Accordion ---------- */
.accordion-panel {
  /* no extra border when collapsed — 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-lg) var(--space-md);
  background: var(--color-surface);
  box-shadow: 0 0 10px var(--color-primary);
}

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

/* ---------- Theme Grid (2-col mobile, auto-fit larger) ---------- */
.theme-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-md);
}

/* ---------- Theme Button (Arcade neon rectangle) ---------- */
.theme-btn {
  font-family: var(--font-display);
  font-size: var(--font-size-md);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  line-height: 1.3;
  background: transparent;
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
  border-radius: var(--border-radius-sm);
  padding: var(--space-lg) var(--space-md);
  min-height: 80px;
  min-width: 48px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  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;
  position: relative;
  overflow: hidden;
}

/* Decorative bottom accent line (arcade detail) */
.theme-btn::after {
  content: '';
  position: absolute;
  bottom: 6px;
  left: 50%;
  transform: translateX(-50%);
  width: 28px;
  height: 2px;
  background: var(--color-accent);
  opacity: 0.5;
  transition: background-color var(--transition-speed), opacity var(--transition-speed);
}

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

.theme-btn:active,
.theme-btn.active {
  transform: scale(0.96);
  box-shadow: 
    0 0 12px var(--color-primary),
    0 0 24px var(--color-primary);
}

/* Selected = filled + stronger neon glow (live preview active) */
.theme-btn.selected {
  background: var(--color-primary);
  color: var(--color-background);
  border-color: var(--color-primary);
  box-shadow: 
    0 0 12px var(--color-primary),
    0 0 24px var(--color-primary);
}

.theme-btn.selected::after {
  background: var(--color-background);
  opacity: 0.9;
}

.theme-btn:disabled,
.theme-btn[disabled] {
  opacity: 0.35;
  pointer-events: none;
  box-shadow: none;
  border-color: var(--color-text-muted);
}

/* Theme name text inside button */
.theme-btn .theme-name {
  font-size: var(--font-size-md);
  font-weight: 400;
  letter-spacing: 0.04em;
}

/* ---------- Update Panel ---------- */
.update-controls {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  gap: var(--space-md);
}

/* The update button inherits .btn base styles — this adds update-specific shape */
.btn-update {
  min-height: 52px;
  min-width: 220px;
  font-size: var(--font-size-md);
  letter-spacing: 0.06em;
  /* Uses --color-accent (yellow) to visually distinguish from theme buttons */
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn-update:hover {
  box-shadow: 0 0 10px var(--color-accent);
}

.btn-update:active {
  transform: scale(0.96);
  box-shadow:
    0 0 12px var(--color-accent),
    0 0 24px var(--color-accent);
}

.btn-update:disabled,
.btn-update[disabled] {
  opacity: 0.4;
  pointer-events: none;
  box-shadow: none;
}

/* Status line below the button — base state is invisible */
.update-status {
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  letter-spacing: 0.04em;
  min-height: 1.4em;
  margin: 0;
  transition: color var(--transition-speed);
  color: var(--color-text-muted);
}

.update-status--checking {
  color: var(--color-accent);
}

.update-status--ok {
  color: var(--color-correct);
  text-shadow: 0 0 6px var(--color-correct);
}

.update-status--error {
  color: var(--color-incorrect);
  text-shadow: 0 0 6px var(--color-incorrect);
}

/* Running cache version label — very dim, purely informational */
.sw-version {
  font-family: var(--font-body);
  font-size: 8px;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  opacity: 0.5;
  margin: 0;
  text-transform: uppercase;
  text-align: center;
  width: 100%;
}

/* ---------- Footer / Back to Menu (bottom, matches other settings) ---------- */
.options-footer {
  margin-top: auto;
  padding-top: var(--space-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
}

.btn-back {
  min-width: 220px;
  min-height: 52px;
  font-size: var(--font-size-md);
  letter-spacing: 0.06em;
}

/* Subtle helper text */
.footer-note {
  font-family: var(--font-body);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  text-align: center;
  letter-spacing: 0.02em;
  opacity: 0.75;
  margin: 0;
  line-height: 1.6;
}

/* ---------- Time slider (shared with session-settings) ---------- */
.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;
}

/* ---------- Accessibility / Focus ---------- */
.theme-btn:focus-visible,
.btn-update:focus-visible,
.accordion-header:focus-visible,
.btn-back:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

/* Ensure everything respects the global CRT scanline + screen-flash from layout.css */
#screen-options {
  /* inherits body::after scanlines and #app.screen-flash animation */
}