/* ── Grid container ───────────────────────────────────── */
.grid-container {
  display: grid;
  gap: 0;
  background: #1F2937;
  border: 2px solid #1F2937;
  border-radius: 4px;
  width: fit-content;
  margin: 0 auto;
  box-sizing: border-box;
  overflow: hidden;
}

/* ── Cell base ────────────────────────────────────────── */
.grid-cell {
  width: var(--cell-size, 40px);
  height: var(--cell-size, 40px);
  min-width: var(--cell-size, 40px);
  min-height: var(--cell-size, 40px);
  max-width: var(--cell-size, 40px);
  max-height: var(--cell-size, 40px);
  background: #FFFFFF;
  border: 1px solid #D1D5DB;
  position: relative;
  cursor: pointer;
  box-sizing: border-box;
  padding: 0;
  margin: 0;
  user-select: none;
  transition: background 0.1s;
}

/* ── Cell states ──────────────────────────────────────── */
.grid-cell.blocked {
  background: #1F2937;
  border-color: #1F2937;
  cursor: default;
}

/* Word highlight (whole selected word) */
.grid-cell.highlight,
.grid-cell.highlighted {
  background: #EEF2FF;
}

/* Active cell (cursor position) */
.grid-cell.active,
.grid-cell.selected {
  background: #4F46E5;
}

/* Validation states */
.grid-cell.correct   { background: #D1FAE5; }
.grid-cell.incorrect { background: #FEE2E2; }

.grid-cell.revealed {
  background: #FEF3C7;
}

/* ── Cell number ──────────────────────────────────────── */
.cell-number {
  position: absolute;
  top: 2px;
  left: 2px;
  font-family: 'Inter', -apple-system, sans-serif;
  font-size: 9px;
  font-weight: 600;
  color: #6B7280;
  line-height: 1;
  z-index: 2;
  pointer-events: none;
}

/* ── Cell input ───────────────────────────────────────── */
.grid-cell input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: none;
  background: transparent;
  text-align: center;
  font-family: 'Inter', -apple-system, sans-serif;
  font-size: 15px;
  font-weight: 700;
  text-transform: uppercase;
  color: #111827;
  padding: 0;
  margin: 0;
  outline: none;
  box-sizing: border-box;
  line-height: var(--cell-size, 40px);
  z-index: 1;
  cursor: pointer;
  caret-color: transparent;
}

.grid-cell input:focus { outline: none; }

.grid-cell.active input,
.grid-cell.selected input {
  background: transparent;
  color: #ffffff;
}

.grid-cell.selected .cell-number {
  color: rgba(255,255,255,0.75);
}

.grid-cell.revealed input {
  color: #92400E;
  font-weight: 700;
}

.grid-cell.incorrect input {
  color: #B91C1C;
}

/* ── Focus ring on cell (keyboard nav) ────────────────── */
.grid-cell:focus-within {
  outline: 2px solid #4F46E5;
  outline-offset: -2px;
  z-index: 3;
}

/* ── number-cell uses data-number attr ────────────────── */
.grid-cell.number-cell::before {
  content: attr(data-number);
  position: absolute;
  top: 2px;
  left: 2px;
  font-family: 'Inter', -apple-system, sans-serif;
  font-size: 9px;
  font-weight: 600;
  color: #6B7280;
  line-height: 1;
  z-index: 2;
  pointer-events: none;
}

/* ── Responsive cell sizing ───────────────────────────── */
@media (max-width: 640px) {
  :root { --cell-size: 32px; }

  .grid-cell input {
    font-size: 13px;
    line-height: 32px;
  }

  .cell-number,
  .grid-cell.number-cell::before {
    font-size: 8px;
  }
}