:root {
    --cell-size: 100px;
    --color: #81c3fd;
    --color-set: #0275d8;
    --1: 10px;
  }
  
  body {
    margin: 0;
  }

  h1 {
    text-align: center;
    font-size: 48px;
  }
  
  .board {
    width: 100vw;
    height: 50vh;
    display: grid;
    justify-content: center;
    align-content: center;
    justify-items: center;
    align-items: center;
    grid-template-columns: repeat(3, auto)
  }
  
  .cell {
    width: var(--cell-size);
    height: var(--cell-size);
    border: 1px solid black;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    cursor: pointer;
  }
  
  
  /* remove border for edges */
  
  .cell:nth-child(1),
  .cell:nth-child(2),
  .cell:nth-child(3) {
    border-top: none;
  }
  
  .cell:nth-child(1),
  .cell:nth-child(4),
  .cell:nth-child(7) {
    border-left: none;
  }
  
  .cell:nth-child(3),
  .cell:nth-child(6),
  .cell:nth-child(9) {
    border-right: none;
  }
  
  .cell:nth-child(7),
  .cell:nth-child(8),
  .cell:nth-child(9) {
    border-bottom: none;
  }
  
  .cell.x,
  .cell.circle {
    cursor: not-allowed;
  }
  
  
  /* for cross */
  
  .board.x .cell:not(.circle, .x):hover::after {
    position: absolute;
    top: 50%;
    left: 50%;
    content: "\D7";
    font-size: 100px;
    font-weight: bolder;
    color: palevioletred;
    transform: translate(-50%, -50%);
  }
  
  
  /* for cross (set) */
  
  .cell.x::after {
    position: absolute;
    top: 50%;
    left: 50%;
    content: "\D7";
    font-size: 100px;
    font-weight: bolder;
    color: red;
    transform: translate(-50%, -50%);
  }
  
  
  /*for circle */
  
  .board.circle .cell:not(.circle, .x):hover {
    background: radial-gradient(var(--color) 60%, transparent 60%);
  }
  
  
  /* for circle (set) */
  
  .cell:not(.x).circle {
    background: radial-gradient(var(--color-set) 60%, transparent 60%)
  }
  
  .winning-message {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-set);
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 5rem;
    font-family: 'Courier New', Courier, monospace;
    flex-direction: column;
  }
  
  .winning-message button {
    border-radius: 10px;
    font-size: 3rem;
    background-color: white;
    border: 1px solid var(--color-set);
    padding: .25em .5em;
    cursor: pointer;
  }
  
  .winning-message button:hover {
    background-color: var(--color-set);
    color: white;
    border-color: white;
  }
  
  .winning-message.show {
    display: flex;
  }