use id for css code example
Example 1: css id
<style>
#your_id{
color: blue;
font-size: 24px;
}
</style>
<h1 id="your_id">Example text</h1>
Example 2: how to call an id in css
<style>
#selector {
color: red;
}
/* # is id selector */
</style>
<div id="selector">
<p>This is an id</p>
</div>