a.button99{
 display:inline-block;
 padding:0.70em 1.9em;
 border:0.15em solid #000000;
 border-radius: 30px;
 margin:0 0.3em 0.3em 0;
 box-sizing: border-box;
 text-decoration:none;
 font-family:'Roboto',sans-serif;
 font-weight: bold;
 font-size: 17px;
 color:#000000;
 text-align:center;
 transition: all 0.2s;
}
a.button99:hover{
 color:#FFFFFF;
 background-color:#000000;
}
@media all and (max-width:30em){
 a.button99{
  display:block;
  margin:0.4em auto;
 }
}