html, body {
    width: 100%;
    height: 100%;
    display: flex;
}


div {
    margin: auto;
    position: relative;
    width: 25vw;
    height: 50vh;
    background: url(https://www.cdsy.xyz/skin/cdsy/images/logo.png) no-repeat;
    background-size: cover;
    mask: linear-gradient(90deg, transparent, #000);
}