how to create neon shadows in css code example

Example 1: css glow effect

div {
    width: 150px;
    height: 150px;
    background-color: #fff;

    box-shadow: 120px 80px 40px 20px #0ff;
    /* in order: x offset, y offset, blur size, spread size, color */
    /* blur size and spread size are optional (they default to 0) */
}

Example 2: css glow text

.glow {
  font-size: 80px;
  color: #fff;
  text-align: center;
  -webkit-animation: glow 1s ease-in-out infinite alternate;
  -moz-animation: glow 1s ease-in-out infinite alternate;
  animation: glow 1s ease-in-out infinite alternate;
}

@-webkit-keyframes glow {
  from {
    text-shadow: 0 0 10px #fff, 0 0 20px #fff, 0 0 30px #e60073, 0 0 40px #e60073, 0 0 50px #e60073, 0 0 60px #e60073, 0 0 70px #e60073;
  }
  
  to {
    text-shadow: 0 0 20px #fff, 0 0 30px #ff4da6, 0 0 40px #ff4da6, 0 0 50px #ff4da6, 0 0 60px #ff4da6, 0 0 70px #ff4da6, 0 0 80px #ff4da6;
  }
}
</style>
 

use/call the class
<h1 class="glow">GLOWING TEXT</h1>