#mainCanvas {
    background: black;
    width: 100%;
    height: 80vh;
}​
/*
#id {
    min-height: 600px;
    height: 600px;
    background-color: blueviolet !important;
}
*/

/* For mobile phones: */
[class*="main-"] {
    width: 100vw;
    height:80vh;
    background-color: black   ;
    margin: 0px;
}

@media only screen and (min-width: 600px) and (min-height:600px) {
    /* For tablets: */
    .main-s-1 {
        width: 100%;
        height:100%;
        background-color: black;
    }
    #mainCanvas {
        width: 100%;
        height: 80vh;
    }​
}

@media only screen and (min-width: 1000px) and (min-height: 800px) {
    /* For desktop: */
    .main-1 {
        width: 100%;
        height: 100%;
        background-color: black;
    }
    #mainCanvas {
        width: 100%;
        height: 80vh;
    }​
}
.info {
    color:yellow ;
}