Edit in JSFiddle


              
<a id="button-1" href="#">Fuente 16px</a>
<a id="button-2" href="#">Fuente 8px</a>
<a id="button-3" href="#">Fuente 22px</a>
body{ width:600px; margin:40px auto; font-family:helvetica;}
a{text-decoration:none; color:white; margin-bottom:30px;}

#button-1{
    width:120px;
    display:block;
    border: 1px solid #395d9b;
    border-radius: 5px;
    text-align:center;
    background:#2b7ab4;
    padding:10px;
    height:40px;
    box-sizing:border-box;
}

#button-2{
    width:120px;
    display:block;
    border: 1px solid #395d9b;
    border-radius: 5px;
    text-align:center;
    background:#2b7ab4;
    padding:10px;
    font-size:12px;
    height:40px;
    box-sizing:border-box;
}

#button-3{
    width:120px;
    display:block;
    border: 1px solid #395d9b;
    border-radius: 5px;
    text-align:center;
    background:#2b7ab4;
    padding:10px;
    font-size:22px;
    height:40px;
    box-sizing:border-box;
}