body {
      font-family: sans-serif;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100vh;
      margin: 0;
      background-color: #1e1e1e; /* Dark background */
      color: #eee;          /* Light text color */
    }

    .board {
      display: grid;
      grid-template-columns: repeat(3, 100px);
      grid-template-rows: repeat(3, 100px);
      border-collapse: collapse;
      margin-bottom: 20px;
    }

    .cell {
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 48px;
      border: 2px solid #eee; /* Light border */
      cursor: pointer;
      background-color: #333; /* Darker cell background */
    }

    .message {
      font-size: 24px;
      margin-bottom: 10px;
    }

    .restart {
      padding: 10px 20px;
      font-size: 16px;
      border: none;
      background-color: #4CAF50; /* Green button */
      color: white;
      cursor: pointer;
    }