style.css

* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
  }
  
  body {
    height: 100vh;
    display: flex;
    flex-direction: column;
    background: #333335;
  }
  #details{
      display: flex;
      align-items: center;
      justify-content: space-evenly;
      margin-top: 70px;
      font-size: 30px;
      color: #cfe6fa;

      
  }
  button{
    font-size: 38px;
    background-color: #333335;
    border-color: rgb(100, 98, 98);
    padding: 8px;
    color: #cfe6fa;
  }

  /* #score{
      margin-right: 200px;
  }
  #timetext{
      margin-left: 200px;
  }  */
  
  #game {
    width: 1080px;
    height: 720px;
    margin: auto;
    display: flex;
    flex-wrap: wrap;
    perspective: 1000px;
  }
  
  .memory-card {
    width: calc(20% - 10px);
    height: calc(25% - 10px);
    margin: 5px;
    position: relative;
    transform: scale(1);
    transform-style: preserve-3d;
    transition: transform .5s;
    box-shadow: 1px 1px 1px rgba(0,0,0,.3);
  }
  
  .memory-card:active {
    transform: scale(0.97);
    transition: transform .2s;
  }
  
  .memory-card.flip {
    transform: rotateY(180deg);
  }
  
  .front-face,
  .back-face {
    width: 100%;
    height: 100%;
    padding: 20px;
    position: absolute;
    border-radius: 5px;
    background: #cfe6fa;
    backface-visibility: hidden;
  }
  
  .front-face {
    transform: rotateY(180deg);
  }