gnu-social/plugins/Cover/assets/css/cover.css

.cover {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: -1;
}

.cover-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.no-cover {
    width: 100%;
    height: 100%;
    background-color: var(--bg2);
}

.profile {
    position: relative;
    background-color: transparent !important;
}