body{
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: black;
}
.box{
    border:2px solid black;
    height:100px;
    width:100px;

}
.parent-box{
     
    height:20rem;
    width:50rem;
    display: flex;
    justify-content: center;
    align-items: center;
    
    gap:30px;
}
#box1{
    background-color: red;

}
#box2{
    background-color:blueviolet;

}
#box3{
    background-color: yellow

}
#box4{
    background-color: green;

}
.aa{
    font-size: 2rem;
  color: white;
  text-shadow:
    0 0 5px white,
    0 0 10px white,
    0 0 20px cyan,
    0 0 40px cyan;

  animation: glow 2s infinite alternate;
}

@keyframes glow {
  from {
    text-shadow:
      0 0 5px white,
      0 0 10px cyan;
  }

  to {
    text-shadow:
      0 0 20px white,
      0 0 40px cyan,
      0 0 80px cyan;
  }
}