a.button {display:block;  text-align:center; margin: 0 auto; width:280px; padding:12px 0 11px; background:#4C4CFF; border-radius:100px; bottom:20px; color:#fff; font-size:18px; background: linear-gradient(90deg, #005DD6 0%, #00A3FF 100%);
    border-radius: 555px;}


/*-----mobile------*/

@media screen and (max-width: 480px){
    a.button {position:fixed; bottom:20px;  z-index:8000; left:0; right:0; margin:auto; }    
}