style.css

*{
    margin: 0px;
    padding: 0px;
    font-family: 'Arial', sans-serif;
  }
  html,body{
    display: grid;
    justify-items: center;
    background: #000;
  }

  .container1{
    height: 150px;
    width: 500px;   
    position: relative;
    background: linear-gradient(135deg, #14ffe9, #ffeb3b, #ff00e0);
    border-radius: 10px;
  }

  .container1 .dispClock{
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: #1b1b1b;
    height: 135px;
    width: 485px;
    border-radius: 6px;
    text-align: center;
  }

  .container1 .dispClock #time{
    line-height: 135px;
    color: #fff;
    font-size: 50px;
    font-weight: 600;
    letter-spacing: 1px;
    font-family: 'Times New Roman', sans-serif;
    background: linear-gradient(135deg, #14ffe9, #ffeb3b, #ff00e0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }

  .container2{
    height: 60px;
    width: 200px;      
    position: relative;
    margin: 20px;
    padding: 10px;
    right: 20px;
    background:#fff;
    border-radius: 10px;
  }

  .decrement{
    position: relative;
    font-family: 'Arial', sans-serif;
    color: #000;
  }

  .buttons{
    position: absolute;
    font-family: 'Arial', sans-serif;
    margin: 5px;
    left: 5px;
    color: #000;
  }