body {
  font-family: sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  background: #f0f8ff;
}

.crossword {
  display: grid;
  grid-template-columns: repeat(20, 30px);
  grid-template-rows: repeat(20, 30px);
  gap: 2px;
  margin: 20px;
}

.cell-wrapper {
  position: relative;
  width: 30px;
  height: 30px;
}

.cell {
  width: 30px;
  height: 30px;
  text-align: center;
  font-size: 18px;
  text-transform: uppercase;
  background-color: white;
  border: 1px solid #ccc;
  color: black;
}

.cell input {
  width: 100%;
  height: 100%;
  border: none;
  text-align: center;
  background: transparent;
  font-size: 16px;
  color: inherit;
}

.cell.black {
  background-color: black;
  pointer-events: none;
}

.cell-number {
  position: absolute;
  top: 2px;
  left: 2px;
  font-size: 10px;
  font-weight: bold;
  color: black;
  z-index: 2;
  pointer-events: none;
}

.cells {
  max-width: 600px;
  margin-top: 20px;
}

.clues ul {
  list-style: none;
  padding: 0;
}

.clues li {
  margin: 4px 0;
}

button {
  margin: 10px;
  padding: 8px 16px;
  font-size: 16px;
  cursor: pointer;
}
.cell.usused {
  background-color: #e0e0e0;
}