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

.wall {
    position:fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    min-width: 400px;
    opacity: 0.8;
    /* background-image: url(../img/R-T-bg.png); */
    overflow: hidden;
    background-color: rgb(2, 12, 21);
    background-size: cover;/* 100% 100%; */
    background-position: center 0;/* center center%; */
    background-repeat: no-repeat;
}