body {
  font-family: Arial, sans-serif;
  background-color: #f0f0f0;
  margin: 0;
  padding: 20px;
}

h1 {
  text-align: center;
  color: #333;
}

#container {
  display: flex;
  flex-direction: column;
  align-items: center;
}

#rule-selector {
  margin-bottom: 20px;
}

#grid {
  display: grid;
  grid-template-columns: repeat(101, 10px);
  grid-template-rows: repeat(101, 10px);
  gap: 1px;
}

.cell {
  width: 10px;
  height: 10px;
  background-color: #fff;
  border: 1px solid #ccc;
}

.cell.alive {
  background-color: #000;
}

#canvas {
  display: block;
  margin: 0 auto;
  border: 1px solid #ccc;
  margin-top: 20px;
  width: 80%;
  aspect-ratio: 16 / 9;
}

#controls {
  display: flex;
  justify-content: center;
  margin-top: 20px;
}

#controls button {
  margin: 0 5px;
  padding: 10px 20px;
  font-size: 16px;
  cursor: pointer;
}

#controls button:hover {
  background-color: #ddd;
}

#controls button:active {
  background-color: #bbb;
}

#controls button:disabled {
  background-color: #ccc;
  cursor: not-allowed;
}

#controls input[type="number"] {
  width: 50px;
  padding: 5px;
  font-size: 16px;
}

#controls input[type="number"]:disabled {
  background-color: #eee;
  cursor: not-allowed;
}

#controls label {
  margin-right: 10px;
}