.botao_preto {
   border-top: 1px solid #000000;
   background: -webkit-gradient(linear, left top, left bottom, from(#000000), to(#696969));
   background: -webkit-linear-gradient(top, #000000, #696969);
   background: -moz-linear-gradient(top, #000000, #696969);
   background: -ms-linear-gradient(top, #000000, #696969);
   background: -o-linear-gradient(top, #000000, #696969);
   padding: 13px 40px;
   color: #ffffff;
   font-size: 24px;
   font-family: Barlow Semi Condensed, Arial;
   text-decoration: none;
   vertical-align: middle;
   margin-top: 50px;
}

.botao_preto:hover {
   border-top-color: #ff7f50;
   background: #ff7f50;
   color: #ffffff;
   text-decoration: none;
}