In order to get CSS saved onto an HTML page you’re working on you will need to either create a <link> element and link to a stylesheet with your CSS rules on it, or add your styles into a <style> tag, or else put your style directly into the elements they’re meant to style inline.
Examples:
Linking in the head
<!-- index.html -->
<head>
<title> Example </title>
<link rel="stylesheet" type="text/css" href="style.css">
</head><!-- style.css -->
p {
color: blue;
}Linking somewhere in your html page
<p>
I like dogs
</p>
<style>
p {
color:blue;
}
</style>Directly in the element in question
<p style="color:blue">
I like dogs
</p>These are the only ways you can natively add CSS styles to your HTML pages.
I hope this helps. I know there are plenty of times when I forget the syntax and have to go look it up.