/* ============================================================
 * Kakuro — self-contained game styles
 * ============================================================
 * Mirrors the Killer/Samurai pattern: defines its own brand
 * variables so the file doesn't depend on sudoku.css. The cell
 * grid uses CSS Grid with equal columns; black cells render a
 * split-diagonal SVG line with two sum labels.
 *
 * CSS variables are scoped to :root so they apply on every page
 * that loads this stylesheet — the engine (`/games/kakuro/`
 * landing is static and never loads it; daily/library pages do).
 */

:root {
  --k-brand:         #1D9E75;
  --k-brand-soft:    rgba(29, 158, 117, 0.15);
  --k-brand-strong:  #0F6E56;
  --k-text:          #212529;
  --k-text-soft:     #555;
  --k-bg:            #ffffff;
  --k-surface:       #f8f9fa;
  --k-border:        #c0c4c9;
  --k-border-dark:   #2d3136;
  --k-black-fill:    #2d3136;
  --k-clue-fg:       #ffffff;
  --k-error:         #E24B4A;
  --k-error-bg:      #ffecec;
  --k-selected:      rgba(29, 158, 117, 0.28);
  --k-highlight:     rgba(29, 158, 117, 0.10);

  --k-radius-sm:     4px;
  --k-radius-md:     8px;
  --k-radius-lg:     12px;
  --k-space-xs:      4px;
  --k-space-sm:      8px;
  --k-space-md:      12px;
  --k-space-lg:      20px;
}

/* ---- Meta bar (difficulty, timer, hints) -------------------- */

.kakuro-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--k-space-md);
  align-items: baseline;
  padding: var(--k-space-sm) var(--k-space-md);
  background: var(--k-surface);
  border-radius: var(--k-radius-md);
}
.kakuro-meta__item { font-size: 0.9rem; color: var(--k-text-soft); }
.kakuro-meta__item strong { color: var(--k-text); margin-left: 4px; }

/* ---- Grid -------------------------------------------------- */

.kakuro-grid-wrapper {
  width: 100%;
  display: flex;
  justify-content: center;
}

.kakuro-grid {
  display: grid;
  width: min(100%, 640px);
  aspect-ratio: 1 / 1;
  border: 2px solid var(--k-border-dark);
  background: var(--k-border-dark);
  gap: 1px;
  user-select: none;
}

.kakuro-grid--paused .kakuro-cell { visibility: hidden; }
.kakuro-grid--loading { opacity: 0.5; pointer-events: none; }

.kakuro-cell {
  position: relative;
  background: var(--k-bg);
  border: 0;
  padding: 0;
  cursor: pointer;
  font-family: inherit;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Black / clue cells */
.kakuro-cell--black {
  background: var(--k-black-fill);
  cursor: default;
}
.kakuro-cell--blocked { background: var(--k-black-fill); }

.kakuro-cell-slash {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.kakuro-cell-slash line {
  stroke: rgba(255, 255, 255, 0.4);
  stroke-width: 1.5;
}

.kakuro-clue {
  position: absolute;
  color: var(--k-clue-fg);
  font-size: clamp(10px, 2.2vw, 16px);
  font-weight: 600;
  line-height: 1;
  pointer-events: none;
}
.kakuro-clue--down  { top: 2px; right: 4px; }
.kakuro-clue--right { bottom: 2px; left: 4px; }

/* White / entry cells */
.kakuro-cell--white {
  background: var(--k-bg);
  color: var(--k-text);
  font-size: clamp(16px, 4vw, 26px);
  font-weight: 500;
}
.kakuro-cell--white:focus-visible {
  outline: 2px solid var(--k-brand);
  outline-offset: -2px;
  z-index: 1;
}
.kakuro-cell--white:hover { background: var(--k-brand-soft); }

.kakuro-cell-value { line-height: 1; }

.kakuro-cell-notes {
  position: absolute;
  inset: 3px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
  gap: 1px;
  font-size: clamp(7px, 1.2vw, 10px);
  color: var(--k-text-soft);
  pointer-events: none;
}
.kakuro-note {
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

/* States (ordered so later ones override) */
.kakuro-cell.kakuro-cell--run-highlight { background: var(--k-highlight); }
.kakuro-cell.kakuro-cell--selected      { background: var(--k-selected); }
.kakuro-cell.kakuro-cell--error         {
  background: var(--k-error-bg);
  color: var(--k-error);
}

/* Hint highlights — declared after the standard states so they win
 * at shared cells. Doubled-class selectors get specificity 0,2,0
 * which beats run-highlight/selected/error without !important.
 * Solid colors (not alpha tints) so the highlights stay readable
 * against the white grid. */
.kakuro-cell.kakuro-cell--hint-region {
  background: #B8E6D3;
  box-shadow: inset 0 0 0 1px var(--k-brand);
}
.kakuro-cell.kakuro-cell--hint-target {
  background: #FFF4B8;
  box-shadow: inset 0 0 0 3px var(--k-brand);
  color: var(--k-text);
}
.kakuro-cell.kakuro-cell--hint-technique {
  background: #FFE066;
  box-shadow: inset 0 0 0 3px var(--k-brand-strong);
  color: var(--k-text);
}
.kakuro-cell.kakuro-cell--hint-filled {
  background: var(--k-brand);
  box-shadow: inset 0 0 0 3px var(--k-brand-strong);
  color: #ffffff;
  font-weight: 700;
}

/* ---- Run info panel ---------------------------------------- */

.kakuro-run-info {
  display: flex;
  flex-wrap: wrap;
  gap: var(--k-space-md);
  padding: var(--k-space-sm) var(--k-space-md);
  background: var(--k-surface);
  border-left: 3px solid var(--k-brand);
  border-radius: var(--k-radius-sm);
  font-size: 0.875rem;
  color: var(--k-text-soft);
}
.kakuro-run-info[hidden] { display: none; }
.kakuro-run-info-row strong { color: var(--k-text); }

/* ---- Controls ---------------------------------------------- */

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

.kakuro-actions {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--k-space-sm);
}
@media (max-width: 400px) {
  .kakuro-actions { grid-template-columns: repeat(3, 1fr); }
}

.kakuro-btn {
  appearance: none;
  background: var(--k-bg);
  border: 1px solid var(--k-border);
  border-radius: var(--k-radius-md);
  padding: 10px 12px;
  font-family: inherit;
  font-size: 0.875rem;
  color: var(--k-text);
  cursor: pointer;
  transition: background-color 0.12s ease, border-color 0.12s ease;
  min-height: 44px;
}
.kakuro-btn:hover { background: var(--k-surface); }
.kakuro-btn:focus-visible {
  outline: 2px solid var(--k-brand);
  outline-offset: 2px;
}
.kakuro-btn--active {
  background: var(--k-brand);
  color: white;
  border-color: var(--k-brand);
}

/* ---- Number pad -------------------------------------------- */

.kakuro-numbers {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  gap: var(--k-space-sm);
}
@media (max-width: 480px) {
  .kakuro-numbers { grid-template-columns: repeat(5, 1fr); }
}

.kakuro-num {
  appearance: none;
  background: var(--k-bg);
  border: 1px solid var(--k-border);
  border-radius: var(--k-radius-md);
  padding: 12px 0;
  font-size: 1.1rem;
  font-weight: 500;
  font-family: inherit;
  color: var(--k-text);
  cursor: pointer;
  min-height: 48px;
  transition: background-color 0.12s ease, color 0.12s ease;
}
.kakuro-num:hover { background: var(--k-brand-soft); }
.kakuro-num:focus-visible {
  outline: 2px solid var(--k-brand);
  outline-offset: 2px;
}

/* ---- New-game row ------------------------------------------ */

.kakuro-new-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--k-space-sm);
  align-items: center;
}
.kakuro-new-row label {
  font-size: 0.875rem;
  color: var(--k-text-soft);
}
.kakuro-new-row select {
  padding: 8px 12px;
  border: 1px solid var(--k-border);
  border-radius: var(--k-radius-md);
  background: var(--k-bg);
  font-family: inherit;
  font-size: 0.9rem;
  min-height: 40px;
}
.kakuro-new-row .kakuro-btn--primary {
  background: var(--k-brand);
  border-color: var(--k-brand);
  color: white;
}
.kakuro-new-row .kakuro-btn--primary:hover {
  background: var(--k-brand-strong);
}

/* ---- Loading / completion overlay -------------------------- */

.kakuro-loading {
  text-align: center;
  padding: var(--k-space-lg);
  color: var(--k-text-soft);
  font-size: 0.95rem;
}
.kakuro-loading[hidden] { display: none; }

.kakuro-completion {
  background: var(--k-brand);
  color: white;
  padding: var(--k-space-lg);
  border-radius: var(--k-radius-lg);
  text-align: center;
}
.kakuro-completion[hidden] { display: none; }
.kakuro-completion h2 { margin: 0 0 var(--k-space-sm); font-size: 1.25rem; }
.kakuro-completion p { margin: 0; font-size: 0.95rem; opacity: 0.9; }

/* Screen-reader announcer */
.kakuro-announcer {
  position: absolute;
  left: -10000px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

/* ---- Mobile ------------------------------------------------- */

@media (max-width: 600px) {
  .kakuro-grid { width: 100%; }
  .kakuro-clue { font-size: clamp(9px, 3vw, 13px); }
  .kakuro-cell--white { font-size: clamp(14px, 5vw, 22px); }
}