body {
  text-align: center;
  padding-top: 50px;
}
.btn-submit {
  padding: 20px 40px;
  border-radius: 50px;
  outline: 0;
  border: 0;
  background: red;
  font-weight: 700;
  color: #fff;
}
.btn-submit:hover {
  background: #f12711; /* fallback for old browsers */
  background: -webkit-linear-gradient(to right, #f12711, #f5af19); /* Chrome 10-25, Safari 5.1-6 */
  background: linear-gradient(to right, #f12711, #f5af19); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
}