<button class="btn">點擊按鈕</button>

.btn {
background-image: linear-gradient(to right, #3a6186, #89253e);
color: #fff;
font-size: 20px;
padding: 10px 20px;
border: none;
border-radius: 5px;
box-shadow: 0 5px 15px rgba(0,0,0,.2);
transition: all .3s ease;
}
.btn:hover {
background-image: linear-gradient(to right, #89253e, #3a6186);
box-shadow: 0 8px 20px rgba(0,0,0,.3);
transform: translateY(-3px);
}