css button background linear gradient
.btn-grad {background-image: linear-gradient(to right, #E55D87 0%, #5FC3E4 51%, #E55D87 100%)}
.btn-grad {
margin: 10px;
padding: 15px 45px;
text-align: center;
text-transform: uppercase;
transition: 0.5s;
background-size: 200% auto;
color: white;
box-shadow: 0 0 20px #eee;
border-radius: 10px;
display: block;
}
.btn-grad:hover {
background-position: right center; /* change the direction of the change here */
color: #fff;
text-decoration: none;
}