font size will change during focus using css :     when i am focusing on link a elements then the only font size is not changing bt i want to change the font size whenever i focus on link a elements of html code...

   
 //css code is there 
    a:focus
        {
            outline-color: ;
            background-color: aqua;
            font-size: 27px;
            
        }
     //and html code also below`
    <ul>
    <li><a href="">home</a></li>
    <li><a href="">h</a></li>
    <li><a href="">m</a></li>
    
    </ul>   