More on selectors

<style>
    h1, h2, .old { /* grouping like declarations */
      font-family: "Courier New";
    }
    
    p.angry { /* only <p> elements with class="angry" */
      color: red;    
    }
        
    #username:hover { /* pseudo class */
      background-color: yellow;        
    }
</style>
    
<h1>Courier</h1>
<h2>New font</h2>
<p class="old">old paragraph, by <span id="username">abc</span></p>
<p class="angry">unhappy paragraph</p>

there is alot of selector patterns you can use with CSS.