css class id

1Select an element with the ID "id" and the class "class":
2#id.class {
3}
4example:
5<div>
6  <strong id="id" class="class">
7      Foobar
8  </strong>
9  <strong class="class">
10      Foobar
11  </strong>
12</div>
13=> Will select the first <strong> element
14
15Select all elements with the class "class",
16which are decendents of a element with an ID of "id":
17#id .class {
18}
19example:
20<div id="id">
21	<strong class="class">Foobar</strong>
22</div>
23=> Will select the <strong> element

1css
2.class
3#id

1.myclass {
2  border:1px solid black;
3  background-color: #d2d2d2;
4  height:20px;
5  width:60px;
6}
7/*If you give this class to a div in html, it will get the styles you gave
8to that class. You can add multiple classes to a div, and multiple divs
9can get that class. */
10/* I hope I helped! */

1/*put a # infront of the id*/
2/*<section id="example"></section>*/
3#example{
4	margin: auto;
5}

1<style>
2  #selector {
3  color: red;
4}
5/* # is id selector */
6</style>
7
8
9<div id="selector">
10<p>This is an id</p>
11</div>
12
13

1.class
2#id