/* ============================================================
 * Killer Sudoku — self-contained styles.
 * Defines its own brand variables so the page renders correctly
 * even when sudoku.css is not loaded.
 * ============================================================ */

/* ============================================================
 * 1. Custom properties
 * ============================================================ */
:root {
  --color-brand: #1D9E75;
  --color-brand-light: #9FE1CB;
  --color-brand-dark: #0F6E56;
  --color-given: #1a1a1a;
  --color-player: #1D9E75;
  --color-invalid: #E24B4A;
  --color-error-bg: #FDEDEC;
  --color-selected: #E1F5EE;
  --color-peer: #f0f9f6;
  --color-cage-highlight: rgba(29, 158, 117, 0.18);
  --color-border-light: #ccc;
  --color-border-dark: #333;
  --color-border-cage: #7a7a7a;
  --color-bg: #f8f8f6;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-muted: #666;
  --color-text-secondary: #333;

  --radius-sm: 6px;
  --radius-md: 10px;
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 12px;
  --space-lg: 16px;

  --transition-fast: 120ms ease-out;

  --touch-target: 44px;
  --focus-ring: 0 0 0 3px rgba(29, 158, 117, 0.45);

  /* Hint highlights — strengths from subtle (level 1) to strong (level 4). */
  --color-hint-region:    rgba(29, 158, 117, 0.22);
  --color-hint-target:    #9FE1CB;
  --color-hint-technique: #FFF3CD;
  --color-hint-filled:    #1D9E75;

  /* Cage palette — assigned by ui.js via --cell-cage-color. Declared
     here for reference / override; the actual per-cell variable is
     set inline by the greedy graph-coloring routine. */
  --cage-color-0: #EBF5FB;
  --cage-color-1: #FEF9E7;
  --cage-color-2: #FDEDEC;
  --cage-color-3: #F4ECF7;
  --cage-color-4: #FEF5E7;
  --cage-color-5: #E8F8F5;
  --cage-color-6: #F2F3F4;
  --cage-color-7: #FDF2E9;
}

/* ============================================================
 * 2. Layout
 * ============================================================ */
.game-main {
  max-width: 560px;
  margin: 0 auto;
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  background: var(--color-bg);
  min-height: calc(100vh - 60px);
  box-sizing: border-box;
}

.game-title {
  font-size: 1.35rem;
  margin: 0;
  color: var(--color-text);
}

.game-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  font-size: 1rem;
  color: var(--color-text);
}

.game-meta__item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
}

.game-meta__timer {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: 1.1rem;
}

/* Timer toggle — mirrors Classic so the shared timer-toggle.js module
   works without modification. */
.game-meta__timer-group { position: relative; }

.timer-toggle {
  appearance: none;
  background: transparent;
  border: none;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 4px 6px;
  font-size: 0.9rem;
  border-radius: var(--radius-sm);
  line-height: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.timer-toggle:hover {
  color: var(--color-text);
  background: var(--color-peer);
}

.timer-toggle:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.timer-toggle-hide { display: none; }
.game-meta__timer-group.timer-hidden .timer-toggle-show { display: none; }
.game-meta__timer-group.timer-hidden .timer-toggle-hide { display: inline; }

.game-meta__timer-group.timer-hidden .game-meta__timer {
  color: transparent;
  user-select: none;
  position: relative;
}

.game-meta__timer-group.timer-hidden .game-meta__timer::after {
  content: '\2014\2009:\2009\2014';
  position: absolute;
  inset: 0;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  font-variant-numeric: tabular-nums;
}

.pencil-indicator {
  color: var(--color-text-muted);
  opacity: 0.35;
  transition: opacity var(--transition-fast), color var(--transition-fast);
}

body.is-pencil-mode .pencil-indicator {
  opacity: 1;
  color: var(--color-brand-dark);
}

/* ============================================================
 * 3. Cage info bar
 * ============================================================ */
.killer-cage-info {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.9rem;
  color: var(--color-text-muted);
  min-height: 22px;
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-sm);
}

.killer-cage-info[hidden] { display: none; }

.killer-cage-info-label {
  font-weight: 600;
  color: var(--color-text-secondary);
}

.killer-cage-info-sum {
  font-weight: 500;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}

/* ============================================================
 * 4. Grid
 * ============================================================ */
.killer-grid {
  position: relative;
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  grid-template-rows: repeat(9, 1fr);
  width: 100%;
  aspect-ratio: 1 / 1;
  max-width: min(100%, 480px);
  margin: 0 auto;
  background: var(--color-surface);
  border: 3px solid var(--color-border-dark);
  box-sizing: border-box;
  user-select: none;
  touch-action: manipulation;
}

.killer-cell {
  position: relative;
  appearance: none;
  background: var(--cell-cage-color, var(--color-surface));
  border: 1px solid var(--color-border-light);
  padding: 0;
  margin: 0;
  font-family: inherit;
  font-size: clamp(1rem, 5vw, 1.6rem);
  color: var(--color-given);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
  min-height: 0;
  aspect-ratio: 1 / 1;
  transition: background-color var(--transition-fast);
}

.killer-cell:focus {
  outline: none;
  box-shadow: inset 0 0 0 3px var(--color-brand);
  z-index: 3;
}

/* Box borders (solid, thick) — must win against cage borders at
   shared edges, so declared AFTER the cage-border rules below. */

.killer-cell--player { color: var(--color-player); font-weight: 600; }
.killer-cell--peer   { background-color: var(--color-peer); }
.killer-cell--cage-highlight {
  /* Overlay the cage base color with a brand-green tint. The linear
     gradient is a trick to keep the underlying cage color visible and
     make the highlight additive, not destructive. */
  background-image: linear-gradient(
    var(--color-cage-highlight),
    var(--color-cage-highlight)
  );
}
.killer-cell--same {
  color: var(--color-brand-dark);
  font-weight: 700;
}
.killer-cell--selected {
  background-color: var(--color-selected);
  box-shadow: inset 0 0 0 2px var(--color-brand);
  z-index: 2;
}
/* Error wins over peer/selected/cage-highlight/same via double-class
   specificity (0,2,0) — higher than any single-class state rule. */
.killer-cell.killer-cell--error {
  color: var(--color-invalid);
  background-color: var(--color-error-bg);
  background-image: none;
}

/* Hint highlighting — additive on top of base cell classes. */
.killer-cell--hint-region {
  background-image: linear-gradient(
    var(--color-hint-region),
    var(--color-hint-region)
  );
}
.killer-cell--hint-technique {
  background-color: var(--color-hint-technique);
}
.killer-cell--hint-target {
  background-color: var(--color-hint-target);
  box-shadow: inset 0 0 0 2px var(--color-brand);
}
.killer-cell--hint-filled {
  background-color: var(--color-hint-filled);
  color: var(--color-surface);
  box-shadow: inset 0 0 0 2px var(--color-brand-dark);
}

/* --- Cage borders (dashed) --- */
.killer-cell.cage-border--top    { border-top:    2px dashed var(--color-border-cage); }
.killer-cell.cage-border--right  { border-right:  2px dashed var(--color-border-cage); }
.killer-cell.cage-border--bottom { border-bottom: 2px dashed var(--color-border-cage); }
.killer-cell.cage-border--left   { border-left:   2px dashed var(--color-border-cage); }

/* Box borders (solid, thick) — declared last so they override the
   dashed cage borders where a cage edge coincides with a box edge. */
.killer-cell--box-left  { border-left:  3px solid var(--color-border-dark); }
.killer-cell--box-top   { border-top:   3px solid var(--color-border-dark); }

/* --- Cage sum label --- */
.killer-cell__sum {
  position: absolute;
  top: 2px;
  left: 3px;
  font-size: clamp(8px, 1.5vw, 11px);
  font-weight: 700;
  line-height: 1;
  color: var(--color-text-secondary);
  pointer-events: none;
  user-select: none;
  z-index: 1;
}

.killer-cell__digit {
  line-height: 1;
  display: inline-block;
  /* Nudge down so the digit doesn't sit on top of the cage sum label. */
  padding-top: 8px;
}

.killer-cell__notes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
  width: 100%;
  height: 100%;
  padding: 2px;
  box-sizing: border-box;
  font-size: clamp(0.5rem, 1.9vw, 0.72rem);
  color: var(--color-text-muted);
  font-weight: 500;
}

.killer-cell__note {
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

body.is-paused .killer-cell__digit,
body.is-paused .killer-cell__notes,
body.is-paused .killer-cell__sum { visibility: hidden; }

body.is-paused .killer-grid::after {
  content: "Paused";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-brand-dark);
  background: var(--color-surface);
  pointer-events: none;
}

/* ============================================================
 * 5. Number pad
 * ============================================================ */
.killer-numpad {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
  max-width: 320px;
  width: 100%;
  margin: 0 auto;
}

.numpad-btn {
  appearance: none;
  min-height: var(--touch-target);
  min-width: var(--touch-target);
  padding: var(--space-md);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: inherit;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.numpad-btn:hover { background: var(--color-peer); }
.numpad-btn:active {
  transform: scale(0.97);
  background: var(--color-brand-light);
}
.numpad-btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.numpad-btn--clear {
  grid-column: 1 / -1;
  background: var(--color-bg);
  color: var(--color-text-muted);
  font-size: 1rem;
  font-weight: 500;
}

body.is-pencil-mode .numpad-btn {
  border-color: var(--color-brand);
  color: var(--color-brand-dark);
}

/* ============================================================
 * 6. Action buttons
 * ============================================================ */
.killer-actions {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-sm);
  max-width: 560px;
  width: 100%;
  margin: 0 auto;
}

@media (max-width: 400px) {
  .killer-actions {
    grid-template-columns: repeat(3, 1fr);
  }
}

.action-btn {
  appearance: none;
  min-height: var(--touch-target);
  padding: var(--space-sm) var(--space-sm);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: inherit;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.action-btn i { pointer-events: none; }
.action-btn:hover { background: var(--color-peer); }
.action-btn:active { transform: scale(0.97); }
.action-btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.action-btn--active {
  background: var(--color-brand);
  color: var(--color-surface);
  border-color: var(--color-brand-dark);
}

.action-btn--primary {
  background: var(--color-brand);
  color: var(--color-surface);
  border-color: var(--color-brand-dark);
}

.killer-controls {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* ============================================================
 * 7. Difficulty selector
 * ============================================================ */
.killer-difficulty-selector {
  position: fixed;
  inset: 0;
  background: rgba(15, 30, 24, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
  z-index: 10;
}
.killer-difficulty-selector[hidden] { display: none; }

.killer-difficulty-selector__panel {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  max-width: 420px;
  width: 100%;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.25);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.killer-difficulty-selector__heading {
  margin: 0;
  font-size: 1.25rem;
  color: var(--color-brand-dark);
  text-align: center;
}

.killer-difficulty-selector__list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-sm);
}

.difficulty-card {
  appearance: none;
  padding: var(--space-md);
  background: var(--color-bg);
  border: 2px solid var(--color-border-light);
  border-radius: var(--radius-md);
  cursor: pointer;
  font-family: inherit;
  min-height: 72px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: var(--space-xs);
  text-align: left;
  transition: border-color var(--transition-fast), transform var(--transition-fast), background-color var(--transition-fast);
}

.difficulty-card:hover {
  border-color: var(--color-brand);
  background: var(--color-peer);
}
.difficulty-card:active { transform: scale(0.98); }
.difficulty-card:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.difficulty-card__label {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-text);
}
.difficulty-card__desc {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.difficulty-card__cancel {
  appearance: none;
  padding: var(--space-sm) var(--space-md);
  background: transparent;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: inherit;
  font-size: 1rem;
  min-height: var(--touch-target);
}
.difficulty-card__cancel:hover { background: var(--color-peer); }
.difficulty-card__cancel:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

/* ============================================================
 * 8. Completion overlay
 * ============================================================ */
.killer-completion {
  position: fixed;
  inset: 0;
  background: rgba(15, 110, 86, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
  z-index: 9;
}
.killer-completion[hidden] { display: none; }

.killer-completion__inner {
  background: var(--color-surface);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  text-align: center;
  min-width: 260px;
  max-width: 380px;
  width: 100%;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.25);
  animation: popIn 240ms ease-out;
}
.killer-completion__inner h2 {
  margin: 0 0 var(--space-sm);
  color: var(--color-brand-dark);
}
.killer-completion__inner p {
  margin: 0 0 var(--space-md);
  font-size: 1.1rem;
  color: var(--color-text);
}

/* Loading overlay */
.killer-loading {
  position: fixed;
  inset: 0;
  background: rgba(15, 30, 24, 0.6);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
  z-index: 11;
  color: var(--color-surface);
  font-size: 1.1rem;
  font-weight: 600;
}
.killer-loading[hidden] { display: none; }

.killer-loading::before {
  content: "";
  width: 40px;
  height: 40px;
  border: 4px solid rgba(255, 255, 255, 0.3);
  border-top-color: var(--color-surface);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Screen reader only live region */
.killer-status {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

/* ============================================================
 * 9. Animations & motion preferences
 * ============================================================ */
@keyframes popIn {
  0%   { transform: scale(0.9); opacity: 0; }
  100% { transform: scale(1);   opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}

/* ============================================================
 * 10. Media queries
 * ============================================================ */
@media (min-width: 768px) {
  .game-main {
    max-width: 900px;
    display: grid;
    grid-template-columns: minmax(0, 1fr) 320px;
    grid-template-areas:
      "title    title"
      "meta     meta"
      "grid     controls"
      "cageinfo cageinfo"
      "load     load";
    gap: var(--space-lg);
    align-items: start;
  }
  .game-title        { grid-area: title; }
  .game-meta         { grid-area: meta; }
  .killer-grid       { grid-area: grid; max-width: 520px; }
  .killer-cage-info  { grid-area: cageinfo; }
  .killer-controls   { grid-area: controls; }
  .killer-loading    { grid-area: load; }
}

@media (min-width: 1024px) {
  .killer-grid { max-width: 560px; }
}

/* ============================================================
 * 11. High-contrast support
 * ============================================================ */
@media (prefers-contrast: more) {
  .killer-cell.cage-border--top,
  .killer-cell.cage-border--right,
  .killer-cell.cage-border--bottom,
  .killer-cell.cage-border--left {
    border-color: #000;
  }
  .killer-cell__sum {
    color: #000;
  }
}