style.css

html{
    font-size:1rem;
    background-image: url('https://cdn.pixabay.com/photo/2017/10/11/23/35/musical-background-2842924_1280.jpg');
    background-size: cover;

}
body, html{
    margin: 0;
    padding: 0;
    font-family: sans-serif;
}
header{
  font-size: 4rem;
  padding-top: 1rem;
  font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
  text-align:center;
  height: 15vh;
  color: rgba(255, 255, 255, 0.897);
  font-weight: 500;

}
.keys {
    display: flex;
    align-items: center;
    justify-content: space-evenly;
    height: 85vh;
    margin-left: 4rem;
    margin-right: 4rem;
    /* flex :1; */
  }
  .key{
    border : 0.5rem black solid;
   border-radius: 10%;
    color : white;
    margin :1rem;
    padding: 0.5rem;
    width:8%;
    transition: all .07s ease;
    background: rgba(0,0,0,0.3);
  }
  kbd{
    display:block;
    font-size: 2rem;
  }
  .playing{
    transform : scale(1.1);
    border-color: #ffc600;
    box-shadow: 0 0 0.8rem rgb(247, 247, 69);
  
  }
  .sound{
    font-weight: 300;
    color: aliceblue;
  }