a.button4{
display:inline-block;
padding:0.5em 1.5em 0.5em  ;
margin:0 0.1em 0.1em 0em;
border:0.16em solid rgba(255,255,255,0);
border-radius:5em;
box-sizing: border-box;
text-decoration:none;
font-family:'Roboto',sans-serif;
font-weight:500;
background-color:#3498DB;
color:#FFFFFF;
text-shadow: 0 0.04em 0.04em rgba(0,0,0,0.35);
text-align:center;
transition: all 0.2s;
text-decoration:none;
}
a.button4:hover{
background-color:#2D2D2D;
text-decoration:none;
color:#FFFFFF;
}
@media all and (max-width:30em){
a.button4{
display:block;
margin:0.2em auto;
}
}