:root {
  --tumblers-bar: #5b2d8e;
  --tumblers-accent: #a855f7;
  --tumblers-accent-dark: #9333ea;
  --tumblers-text: #2a1f3d;
  --c0: #c94c4c;
  --c1: #c9a227;
  --c2: #3f9a5a;
  --c3: #5b6b8a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", "Trebuchet MS", sans-serif;
  background:
    radial-gradient(ellipse at top, #ede9fe 0%, transparent 55%),
    linear-gradient(180deg, #f5f3ff 0%, #e9e4f5 100%);
  color: var(--tumblers-text);
  min-height: 100vh;
}

.tumblers-chrome {
  background: var(--tumblers-bar);
  color: #fff;
  padding: 0.65rem 1rem;
}

.tumblers-chrome__brand {
  max-width: 40rem;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.tumblers-chrome__logo {
  color: #f3e8ff;
  font-weight: 700;
  text-decoration: none;
  font-size: 1.15rem;
}

.tumblers-chrome__links a {
  color: #e9d5ff;
  margin-left: 0.85rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
}

.tumblers-chrome__links a:hover {
  color: #f3e8ff;
  text-decoration: underline;
}

.tumblers-main {
  max-width: 28rem;
  margin: 1.25rem auto 2.5rem;
  padding: 0 1rem;
}

.tumblers-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.85rem;
}

.tumblers-meta {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.tumblers-play-date {
  font-weight: 700;
  color: var(--tumblers-bar);
}

.tumblers-difficulty {
  font-size: 0.85rem;
  text-transform: capitalize;
  color: #64748b;
}

#tumblers-timer {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--tumblers-bar);
}

.tumblers-btn {
  appearance: none;
  border: none;
  border-radius: 5px;
  padding: 0.55rem 0.9rem;
  font-weight: 700;
  cursor: pointer;
  font-size: 0.9rem;
}

.tumblers-btn--secondary {
  background: #e2e8f0;
  color: var(--tumblers-bar);
}

.tumblers-btn--secondary:hover {
  background: #cbd5e1;
}

.tumblers-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.tumblers-status {
  min-height: 1.4rem;
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
}

.tumblers-status--ok {
  color: #166534;
  font-weight: 600;
}

.tumblers-status--err {
  color: #991b1b;
  font-weight: 600;
}

.tumblers-target {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.85rem;
  font-weight: 600;
}

.tumblers-target__swatch {
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 4px;
  border: 2px solid #1f2430;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.25);
}

.tumblers-board {
  position: relative;
  display: grid;
  gap: 0.35rem;
  width: min(100%, 18rem);
  margin: 0 auto 1.25rem;
  aspect-ratio: 1;
  overflow: hidden;
}

.tumblers-board--size-3 {
  grid-template-columns: repeat(3, 1fr);
}

.tumblers-board--size-4 {
  grid-template-columns: repeat(4, 1fr);
}

.tumblers-board--size-5 {
  grid-template-columns: repeat(5, 1fr);
}

.tumblers-cell {
  border-radius: 8px;
  border: 2px solid rgba(31, 36, 48, 0.35);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.2);
}

.tumblers-board.is-cycling .tumblers-cell {
  transition: background-color 0.18s ease;
}

.tumblers-cell-fly {
  position: absolute;
  z-index: 2;
  border-radius: 8px;
  border: 2px solid rgba(31, 36, 48, 0.35);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.2);
  pointer-events: none;
  transition: transform 0.22s ease;
  will-change: transform;
}

.tumblers-cell--c0 { background: var(--c0); }
.tumblers-cell--c1 { background: var(--c1); }
.tumblers-cell--c2 { background: var(--c2); }
.tumblers-cell--c3 { background: var(--c3); }

/* Colour-blind hatch overlays (account preference → body.colourblind-patterns) */
body.colourblind-patterns .tumblers-cell--c0,
body.colourblind-patterns .tumblers-cell-fly.tumblers-cell--c0 {
  background-color: var(--c0);
  background-image: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 4px,
    rgba(0, 0, 0, 0.4) 4px,
    rgba(0, 0, 0, 0.4) 8px
  );
}
body.colourblind-patterns .tumblers-cell--c1,
body.colourblind-patterns .tumblers-cell-fly.tumblers-cell--c1 {
  background-color: var(--c1);
  background-image: radial-gradient(
    circle at 3px 3px,
    rgba(0, 0, 0, 0.45) 1.75px,
    transparent 1.9px
  );
  background-size: 9px 9px;
}
body.colourblind-patterns .tumblers-cell--c2,
body.colourblind-patterns .tumblers-cell-fly.tumblers-cell--c2 {
  background-color: var(--c2);
  background-image: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 4px,
    rgba(0, 0, 0, 0.4) 4px,
    rgba(0, 0, 0, 0.4) 8px
  );
}
body.colourblind-patterns .tumblers-cell--c3,
body.colourblind-patterns .tumblers-cell-fly.tumblers-cell--c3 {
  background-color: var(--c3);
  background-image:
    repeating-linear-gradient(
      45deg,
      transparent,
      transparent 5px,
      rgba(0, 0, 0, 0.35) 5px,
      rgba(0, 0, 0, 0.35) 6px
    ),
    repeating-linear-gradient(
      -45deg,
      transparent,
      transparent 5px,
      rgba(0, 0, 0, 0.35) 5px,
      rgba(0, 0, 0, 0.35) 6px
    );
}

@media (prefers-reduced-motion: reduce) {
  .tumblers-cell,
  .tumblers-cell-fly {
    transition: none;
  }
}

.tumblers-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
}

.tumblers-action {
  appearance: none;
  border: none;
  border-radius: 6px;
  padding: 0.65rem 0.85rem;
  background: var(--tumblers-accent);
  color: #fff;
  font-weight: 700;
  cursor: pointer;
  font-size: 0.88rem;
}

.tumblers-action:hover {
  background: var(--tumblers-accent-dark);
}

.tumblers-action:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

@media (max-width: 420px) {
  .tumblers-board {
    width: 100%;
  }
}