How does CSS implement a tick on a menu? Code

What this article brings to you is about how CSS implements a tick on a menu. (code), there is a certain reference value, the need for friends can refer to, I hope to help you.

<! DOCTYPE html>


The effect is as follows:


Key CSS:

Li.done::before {    content: ';    Position:absolute;    Border-color: #009933;    Border-style:solid;    border-width:0 0.3em 0.25em 0;    Height:1em;    Top:1.3em;    Left:0.6em;    Margin-top: -1em;    Transform:rotate (45deg);    Width:0.5em;}
* Bootstrap downward triangle for drop-down menu

. caret {    border-left:4px solid transparent;    border-right:4px solid transparent;    BORDER-TOP:4PX dashed;    Display:inline-block;    height:0;    margin-left:2px;    Vertical-align:middle;    width:0;}