transform: scale();
<div class="container__font">
<div class="container__font--size">FONT SIZE</div>
</div>
.container__font{
width: 200px;
height: 50px;
border: 1px solid red;
line-height: 50px;
text-align: center;
overflow: hidden;
}
.container__font--size{
transition: .5s;
}
.container__font--size:hover{
cursor: pointer;
transform: scale(1.5);
background-color: red;
color: white;
}