/* Cover */

.cover {
    position: absolute;
    top: 50%;
    left: 50%;
    z-index: -1;
    transform: translate(-50%, -50%);
    max-width: 100%;
    max-height: 100%;
}

/* Fitting */

.cover.w,
.cover.width {
    width: 100%;
    max-height: none;
}

.cover.h,
.cover.height {
    height: 100%;
    max-width: none;
}