how to use unicode in css

1/*
2Notes Before Start:
31_ unicode can be added only for css 'content' property.
42_ content property cannot be used without ::before and ::after pesudo classes.
53_ if you use content without applying step 2 nothing will be affected.
6*/
7.my-div{
8  background-color: #f00;
9  border: 2px solid #00f;
10}
11.my-div::after{
12  content: "\00a9"; /* Copyright Icon */
13  font-size: 40px;
14  color: #fff;
15}
16/*
17You can use unicode inside your html by adding &
18HTML copyright icon: <p>&copy;</p>
19CSS copyright icon: example above
20*/