/* 2048 Merge — pixel merge-lab skin.
 *
 * Shared geometry comes from the --pixel-* tokens in /assets/css/tokens.css.
 * The Shell pixel.css is not loaded inside the iframe. Every colour, border,
 * shadow and animation below is local to this game.
 */

:root {
  color-scheme: light;

  --merge-grid: var(--pixel-grid-size);
  --merge-border: var(--pixel-border-width);
  --merge-border-thin: var(--pixel-border-thin);
  --merge-shadow: var(--pixel-shadow-offset);
  --merge-shadow-lg: var(--pixel-shadow-offset-lg);
  --merge-font: var(--pixel-ui-font);

  --merge-bg: #efe7d8;
  --merge-bg-2: #e0d5c0;
  --merge-surface: #fff9ec;
  --merge-surface-2: #f3ead7;
  --merge-surface-3: #e6dac2;
  --merge-ink: #332a1f;
  --merge-muted: #7a6a56;
  --merge-line: #332a1f;
  --merge-accent: #d9662b;
  --merge-accent-2: #2f8f7a;
  --merge-accent-soft: #f6d7bf;
  --merge-danger: #b23a48;
  --merge-danger-soft: #f2c9c0;
  --merge-success: #4f8a4a;
  --merge-on-accent: #fff9ec;
  --merge-scrim: rgba(26, 20, 12, 0.78);

  --merge-board-face: #b7a88f;
  --merge-board-edge: #8f7f68;
  --merge-cell-face: #cec1ab;
  --merge-cell-alt: #c6b79f;
  --merge-cell-edge: #bdaf98;
  --merge-focus: #d9662b;

  --merge-tile-2: #eee4da;
  --merge-tile-2-ink: #332a1f;
  --merge-tile-4: #ece0c8;
  --merge-tile-4-ink: #332a1f;
  --merge-tile-8: #f2b179;
  --merge-tile-8-ink: #3a2a1a;
  --merge-tile-16: #f59563;
  --merge-tile-16-ink: #3a2a1a;
  --merge-tile-32: #f67c5f;
  --merge-tile-32-ink: #fff9ec;
  --merge-tile-64: #f65e3b;
  --merge-tile-64-ink: #fff9ec;
  --merge-tile-128: #edcf72;
  --merge-tile-128-ink: #332a1f;
  --merge-tile-256: #edcc61;
  --merge-tile-256-ink: #332a1f;
  --merge-tile-512: #edc850;
  --merge-tile-512-ink: #332a1f;
  --merge-tile-1024: #edc53f;
  --merge-tile-1024-ink: #332a1f;
  --merge-tile-2048: #edc22e;
  --merge-tile-2048-ink: #332a1f;
  --merge-tile-4096: #3c3a32;
  --merge-tile-4096-ink: #f5edda;

  --merge-sprite-size: 400% 200%;
  --merge-sprite-hero: 0% 0%;
  --merge-sprite-coin: 33.333% 0%;
  --merge-sprite-hazard: 66.667% 0%;
  --merge-sprite-effect: 100% 0%;
  --merge-sprite-tile: 0% 100%;
  --merge-sprite-block: 33.333% 100%;
  --merge-sprite-spark: 66.667% 100%;
}

[data-theme="dark"] {
  color-scheme: dark;

  --merge-bg: #14161c;
  --merge-bg-2: #1e222b;
  --merge-surface: #262b36;
  --merge-surface-2: #202530;
  --merge-surface-3: #2f3542;
  --merge-ink: #f5edda;
  --merge-muted: #a89a86;
  --merge-line: #f5edda;
  --merge-accent: #ff9f5a;
  --merge-accent-2: #5fd1bd;
  --merge-accent-soft: #4a3320;
  --merge-danger: #ff7a8a;
  --merge-danger-soft: #4a262e;
  --merge-success: #82d68f;
  --merge-on-accent: #1a1206;
  --merge-scrim: rgba(2, 4, 8, 0.84);

  --merge-board-face: #22262e;
  --merge-board-edge: #0f1217;
  --merge-cell-face: #2c313b;
  --merge-cell-alt: #262b34;
  --merge-cell-edge: #3a404d;
  --merge-focus: #ff9f5a;

  --merge-tile-2: #3a3f4a;
  --merge-tile-2-ink: #f5edda;
  --merge-tile-4: #444a56;
  --merge-tile-4-ink: #f5edda;
  --merge-tile-8: #8a5a3a;
  --merge-tile-8-ink: #fff4e0;
  --merge-tile-16: #a9693f;
  --merge-tile-16-ink: #fff4e0;
  --merge-tile-32: #c07a46;
  --merge-tile-32-ink: #1a1206;
  --merge-tile-64: #d98a4b;
  --merge-tile-64-ink: #1a1206;
  --merge-tile-128: #b99a3f;
  --merge-tile-128-ink: #1a1206;
  --merge-tile-256: #c9a83f;
  --merge-tile-256-ink: #1a1206;
  --merge-tile-512: #d9b540;
  --merge-tile-512-ink: #1a1206;
  --merge-tile-1024: #e6c243;
  --merge-tile-1024-ink: #1a1206;
  --merge-tile-2048: #f5d35a;
  --merge-tile-2048-ink: #1a1206;
  --merge-tile-4096: #6b7280;
  --merge-tile-4096-ink: #f5edda;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
  background: var(--merge-bg);
  overscroll-behavior: none;
}

body {
  color: var(--merge-ink);
  font-family: var(--merge-font);
  font-size: 16px;
  line-height: 1.4;
  -webkit-font-smoothing: none;
  text-rendering: optimizeSpeed;
  -webkit-tap-highlight-color: transparent;
}

button,
canvas {
  touch-action: manipulation;
}

button {
  color: inherit;
  font: inherit;
}

button:focus-visible,
canvas:focus-visible {
  outline: var(--merge-border) solid var(--merge-focus);
  outline-offset: 2px;
}

[hidden] {
  display: none !important;
}

/* App --------------------------------------------------------------------- */

.merge-app {
  position: relative;
  isolation: isolate;
  display: grid;
  width: 100%;
  height: 100dvh;
  min-height: 0;
  grid-template-areas:
    "header"
    "stats"
    "board"
    "actions"
    "hint";
  grid-template-rows: auto auto minmax(0, 1fr) auto auto;
  gap: var(--merge-grid);
  padding:
    max(var(--merge-grid), env(safe-area-inset-top))
    max(var(--merge-grid), env(safe-area-inset-right))
    max(var(--merge-grid), env(safe-area-inset-bottom))
    max(var(--merge-grid), env(safe-area-inset-left));
  overflow: hidden;
  background: var(--merge-bg);
}

.merge-app::before {
  position: absolute;
  z-index: 0;
  inset: 0;
  content: "";
  background-color: var(--merge-bg);
  pointer-events: none;
}

.merge-scene {
  position: absolute;
  z-index: 0;
  inset: 0;
  background-color: var(--merge-bg);
  background-image: url("../assets/2048-merge-light.png");
  background-position: center;
  background-size: cover;
  image-rendering: pixelated;
  opacity: 0.18;
  pointer-events: none;
}

[data-theme="dark"] .merge-scene {
  background-image: url("../assets/2048-merge-dark.png");
  opacity: 0.28;
}

.merge-header,
.merge-main,
.merge-overlay,
.merge-stats,
.merge-board-col,
.merge-actions,
.merge-hint {
  position: relative;
  z-index: 1;
}

/* Header ------------------------------------------------------------------ */

.merge-header {
  display: grid;
  min-height: 44px;
  grid-area: header;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 6px;
  padding: 4px;
  border: var(--merge-border) solid var(--merge-line);
  background: var(--merge-surface);
  box-shadow: var(--merge-shadow) var(--merge-shadow) 0 var(--merge-line);
}

.merge-brand {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: 8px;
}

.merge-brand__mark {
  width: 32px;
  height: 32px;
  flex: 0 0 auto;
  border: var(--merge-border-thin) solid var(--merge-line);
  background-color: var(--merge-accent-soft);
  background-image: url("../assets/pixel/2048-merge-sprites.png");
  background-repeat: no-repeat;
  background-size: var(--merge-sprite-size);
  background-position: var(--merge-sprite-tile);
  box-shadow: 2px 2px 0 var(--merge-line);
  image-rendering: pixelated;
}

.merge-brand__copy {
  display: flex;
  min-width: 0;
  flex-direction: column;
  line-height: 1.1;
}

.merge-brand__copy h1 {
  margin: 0;
  overflow: hidden;
  font-size: 18px;
  font-weight: 700;
  text-overflow: ellipsis;
  text-transform: uppercase;
  white-space: nowrap;
}

.merge-brand__copy p {
  margin: 1px 0 0;
  overflow: hidden;
  color: var(--merge-muted);
  font-size: 12px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.merge-header__hint {
  display: none;
  margin: 0;
  color: var(--merge-muted);
  font-size: 12px;
  white-space: nowrap;
}

/* Main -------------------------------------------------------------------- */

.merge-main {
  display: grid;
  min-height: 0;
  grid-area: 2 / 1 / -1 / -1;
  grid-template-areas:
    "stats"
    "board"
    "actions"
    "hint";
  grid-template-rows: auto minmax(0, 1fr) auto auto;
  gap: var(--merge-grid);
}

.merge-stats {
  display: grid;
  grid-area: stats;
  grid-template-columns: 1fr 1fr;
  gap: var(--merge-grid);
}

.merge-stat {
  display: flex;
  min-width: 0;
  flex-direction: column;
  align-items: center;
  padding: 2px 8px;
  border: var(--merge-border) solid var(--merge-line);
  background: var(--merge-surface);
  box-shadow: var(--merge-shadow) var(--merge-shadow) 0 var(--merge-line);
  line-height: 1.1;
}

.merge-stat--best {
  background: var(--merge-accent-soft);
}

.merge-stat span {
  overflow: hidden;
  width: 100%;
  color: var(--merge-muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-align: center;
  text-overflow: ellipsis;
  text-transform: uppercase;
  white-space: nowrap;
}

.merge-stat strong {
  overflow: hidden;
  width: 100%;
  font-size: 22px;
  font-variant-numeric: tabular-nums;
  text-align: center;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.merge-board-col {
  display: grid;
  min-width: 0;
  min-height: 0;
  grid-area: board;
  place-items: center;
}

.merge-board-wrap {
  position: relative;
  display: grid;
  width: 100%;
  max-width: 100%;
  aspect-ratio: 1 / 1;
  place-items: center;
  overflow: hidden;
  border: var(--merge-border) solid var(--merge-line);
  background: var(--merge-board-face);
  box-shadow: var(--merge-shadow-lg) var(--merge-shadow-lg) 0 var(--merge-line);
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  transition: transform 80ms steps(2, end);
}

.merge-board-wrap.is-pressed {
  transform: translateY(2px);
}

.merge-board-wrap.is-shaking {
  animation: merge-shake 150ms steps(2, end);
}

.merge-board-wrap.is-flashing {
  box-shadow: 0 0 0 var(--merge-border) var(--merge-focus),
    var(--merge-shadow-lg) var(--merge-shadow-lg) 0 var(--merge-line);
}

.merge-board-wrap.is-invalid {
  box-shadow: 0 0 0 var(--merge-border) var(--merge-danger),
    var(--merge-shadow-lg) var(--merge-shadow-lg) 0 var(--merge-line);
}

#board {
  display: block;
  max-width: 100%;
  max-height: 100%;
  border: 0;
  background: transparent;
  image-rendering: pixelated;
  touch-action: none;
}

/* Actions ----------------------------------------------------------------- */

.merge-actions {
  display: grid;
  grid-area: actions;
  grid-template-columns: 1fr 1fr;
  gap: var(--merge-grid);
}

.merge-btn {
  display: inline-flex;
  min-width: var(--touch-target-min);
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 4px 10px;
  border: var(--merge-border) solid var(--merge-line);
  background: var(--merge-surface);
  box-shadow: var(--merge-shadow) var(--merge-shadow) 0 var(--merge-line);
  cursor: pointer;
  font-family: var(--merge-font);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.1;
  text-align: center;
  text-transform: uppercase;
  touch-action: manipulation;
  user-select: none;
  transition: transform 80ms steps(2, end);
}

.merge-btn__icon {
  width: 24px;
  height: 24px;
  flex: 0 0 auto;
  border: var(--merge-border-thin) solid var(--merge-line);
  background-color: var(--merge-surface-2);
  background-image: url("../assets/pixel/2048-merge-sprites.png");
  background-repeat: no-repeat;
  background-size: var(--merge-sprite-size);
  image-rendering: pixelated;
}

.merge-btn__icon--new {
  background-position: var(--merge-sprite-block);
}

.merge-btn__icon--undo {
  background-position: var(--merge-sprite-tile);
}

.merge-btn__icon--share {
  background-position: var(--merge-sprite-spark);
}

.merge-btn--primary {
  color: var(--merge-on-accent);
  background: var(--merge-accent);
}

.merge-btn--secondary {
  background: var(--merge-surface-2);
}

.merge-btn:active:not(:disabled) {
  transform: translate(var(--merge-shadow), var(--merge-shadow));
  box-shadow: 0 0 0 var(--merge-line);
}

.merge-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.merge-hint {
  grid-area: hint;
  margin: 0;
  color: var(--merge-muted);
  font-size: 12px;
  line-height: 1.45;
  text-align: center;
}

.merge-hint__keys {
  display: none;
  white-space: nowrap;
}

kbd {
  padding: 0 3px;
  border: var(--merge-border-thin) solid var(--merge-line);
  background: var(--merge-surface-2);
  font-family: inherit;
  font-size: 0.92em;
  font-weight: 700;
}

/* Overlays ---------------------------------------------------------------- */

.merge-overlay {
  position: fixed;
  z-index: 20;
  inset: 0;
  display: grid;
  overflow: auto;
  padding:
    max(16px, env(safe-area-inset-top))
    max(16px, env(safe-area-inset-right))
    max(16px, env(safe-area-inset-bottom))
    max(16px, env(safe-area-inset-left));
  place-items: center;
  background: var(--merge-scrim);
}

.merge-card {
  width: min(100%, 390px);
  max-height: 80vh;
  overflow: auto;
  padding: 16px;
  border: var(--merge-border) solid var(--merge-line);
  background: var(--merge-surface);
  box-shadow: var(--merge-shadow-lg) var(--merge-shadow-lg) 0 var(--merge-line);
  text-align: center;
  animation: merge-card-in 160ms steps(3, end);
}

.merge-card--compact {
  max-width: 360px;
}

.merge-card--win {
  background: var(--merge-surface);
}

.merge-card__badge {
  width: 64px;
  height: 64px;
  margin: 0 auto 8px;
  border: var(--merge-border) solid var(--merge-line);
  background-color: var(--merge-accent-soft);
  background-image: url("../assets/pixel/2048-merge-sprites.png");
  background-repeat: no-repeat;
  background-size: var(--merge-sprite-size);
  background-position: var(--merge-sprite-hero);
  box-shadow: var(--merge-shadow) var(--merge-shadow) 0 var(--merge-line);
  image-rendering: pixelated;
}

.merge-card__badge--win {
  background-color: var(--merge-accent-soft);
  background-position: var(--merge-sprite-spark);
}

.merge-card__badge--danger {
  background-color: var(--merge-danger-soft);
  background-position: var(--merge-sprite-hazard);
}

.merge-eyebrow {
  margin: 0 0 4px;
  color: var(--merge-accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.merge-card__title {
  margin: 0 0 8px;
  font-size: 24px;
  line-height: 1.1;
  text-transform: uppercase;
}

.merge-card__text {
  margin: 0 0 12px;
  color: var(--merge-muted);
  font-size: 14px;
}

.merge-result {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--merge-grid);
  margin: 12px 0;
}

.merge-result span {
  display: flex;
  min-width: 0;
  flex-direction: column;
  padding: 6px;
  border: var(--merge-border-thin) solid var(--merge-line);
  background: var(--merge-surface-2);
  line-height: 1.1;
}

.merge-result small {
  color: var(--merge-muted);
  font-size: 12px;
  text-transform: uppercase;
}

.merge-result strong {
  overflow: hidden;
  font-size: 18px;
  font-variant-numeric: tabular-nums;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.merge-card__actions {
  display: grid;
  gap: var(--merge-grid);
  margin-top: 12px;
}

.merge-card__actions .merge-btn {
  width: 100%;
}

.is-pop {
  animation: merge-pop 260ms steps(4, end);
  transform-origin: center;
}

.merge-sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  margin: -1px;
  padding: 0;
  border: 0;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

/* Animations -------------------------------------------------------------- */

@keyframes merge-shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-4px);
  }
  75% {
    transform: translateX(4px);
  }
}

@keyframes merge-card-in {
  0% {
    transform: translateY(6px);
    opacity: 0.5;
  }
  100% {
    transform: translateY(0);
    opacity: 1;
  }
}

@keyframes merge-pop {
  0% {
    transform: scale(1);
  }
  40% {
    transform: scale(1.12);
  }
  100% {
    transform: scale(1);
  }
}

/* Responsive -------------------------------------------------------------- */

@media (min-width: 480px) {
  .merge-hint {
    font-size: 13px;
  }

  .merge-hint__keys {
    display: inline;
  }
}

@media (min-aspect-ratio: 1 / 1) {
  .merge-app {
    grid-template-areas:
      "board header"
      "board stats"
      "board actions"
      "board hint";
    grid-template-columns: minmax(0, 1fr) minmax(220px, 34%);
    grid-template-rows: auto auto minmax(0, 1fr) auto;
    gap: var(--merge-grid);
    padding-inline: max(var(--merge-grid), env(safe-area-inset-left));
  }

  .merge-header {
    grid-area: header;
  }

  .merge-main {
    display: contents;
  }

  .merge-stats {
    grid-area: stats;
    align-content: start;
  }

  .merge-board-col {
    grid-area: board;
  }

  .merge-board-wrap {
    max-width: 100%;
    margin-inline: auto;
  }

  .merge-actions {
    grid-area: actions;
    align-self: end;
    grid-template-columns: 1fr;
  }

  .merge-hint {
    grid-area: hint;
    align-self: end;
    text-align: left;
  }
}

@media (max-height: 430px) {
  .merge-brand__copy p,
  .merge-hint__keys {
    display: none;
  }

  .merge-hint {
    font-size: 12px;
  }

  .merge-stat {
    padding-block: 1px;
  }

  .merge-stat strong {
    font-size: 18px;
  }

  .merge-header {
    min-height: 44px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0ms !important;
    animation-delay: 0ms !important;
    transition-duration: 0ms !important;
    scroll-behavior: auto !important;
  }

  .merge-board-wrap {
    transform: none !important;
  }
}