button {
        position: absolute;
        padding: 10px 20px;
        top: 50px;
        left: 50px;
        border: none;
        border-radius: 4px;
        color: #fff;
        font: 16px sans-serif;
        /* set up background gradient and animation */
        background-image: linear-gradient(#36
 
d279, #1d854a);
        background-size: auto 200%;
        background-position: 0 100%;
        transition: background-position 0.5s;
    }
    button:hover {
        /* shift background gradient position */
        background-position: 0 0;
        cursor: pointer;
    }