How can we give some perspective to an element?

The perspective CSS property determines the distance between the z=0 plane and the user in order to give a 3D-positioned element some perspective.

/* Keyword value */
perspective: none;

/* <length> values */
perspective: 20px;
perspective: 3.5em;

/* Global values */
perspective: inherit;
perspective: initial;
perspective: unset;

Source: https://developer.mozilla.org/en-US/docs/Web/CSS/perspective