style-2.css

.btn {

  background: transparent;
  font-size: -rem(10px);
  font-size: 2.0cm;     /*文字大小*/
  letter-spacing: 0.3em;   /*文字間距*/
  color: rgba(223,190,106,0.7); /*顏色*/
  border-radius: 0;
  padding: 18px 80px 20px;
  width: 600px;
  height: 150px;
  -webkit-transition: all 0.7s ease-out;
  transition: all 0.7s ease-out;
  background: -webkit-linear-gradient(180deg, rgba(223,190,106,0.8), rgba(146,111,52,0.8), rgba(0,0,0,0), rgba(0,0,0,0));
  background: linear-gradient(270deg, rgba(223,190,106,0.8), rgba(146,111,52,0.8), rgba(0,0,0,0), rgba(0,0,0,0));
  background-position: 1% 50%;
  background-size: 300% 300%;
  text-decoration: none;
  margin: -rem(10px);
  border: none;
  border: 1px solid rgba(223,190,106,0.3);
}
.btn:hover {
  color: #fff;
  border: 1px solid rgba(223,190,106,0);
  color: $white;
  background-position: 99% 50%;
}