how to give 3d effect to div in css code example

Example 1: css shadow

.yourElement {
  /* offset-x | offset-y | blur-radius | spread-radius | color */
  -webkit-box-shadow: -2px -1px 15px 7px rgba(0,0,0,0.5);
  -moz-box-shadow: -3px -2px 30px 14px rgba(0,0,0,0.425);
  box-shadow: -4px -3px 45px 21px rgba(0,0,0,0.35);
}

Example 2: drop shadow image css

filter: drop-shadow(0px 10px 3px black);