how to use ids in css code example

Example 1: css id

#id {
  css declarations;
}
Demo

Example 2: id in css

#id{
    color:red;
}

Example 3: css how to style id

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

Example 4: referance html id css

<style>
  #test {
  /*Styleing here*/
  }
</style>
<h1 id="test"></h1>