Laravel how to return css in function

So I have a function which I want to return this span class code

I already set the class code in my CSS

.subject{
   position:absolute;
   color: white;
   text-decoration: none;
   padding: 0px 25px 12px 0px;
   display: inline-block;
   border-radius: 2px;
}    

So my function created is this

function subject() {
return '<span class="subject"></span>';
}

I call the function like this in the blade

{{subject()}}

May I know why when I call the function it just return the code

'<span class="subject"></span>';