.center {
  margin: 0;
  position: absolute;
  top: 80%;
  left: 50%;
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

.button1 {
  background-color: #742b8b; 
  border: none;
  color: white;
  padding: 15px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  margin: 4px 14px;
  cursor: pointer;
  -webkit-transition-duration: 0.4s; /* Safari */
  transition-duration: 0.4s;
  box-shadow: 0 8px 16px 0 rgba(0,0,0,0.2), 0 6px 20px 0 rgba(0,0,0,0.19);
}