how to add before property in css code example

Example: css after before

/*
	"before" & "after" are pseudo-contents.
	They end up *into* the tag they are declared for.
	They are just right "before" or "after" the *content* of tag they're in.
	Declare their "content" CSS rule to make them visible.
*/
div::before			/* <div>|here|Content of tag</div> */
{
  content: "|here|";
}
div::after				/* <div>Content of tag|here|</div> */
{
  content: "|here|";
}

/*
	Double-colon should be used: it's the meant pseudo-content operator.
	IE8 doesn't support it though: it supports single-colon (meant for pseudo-selectors).
	So IE8 support needs the following:
	div:before { ... }
	div:after { ... }
*/