gnu-social/public/assets/css/network/public.css

.content {
    display: flex;
    flex-wrap: wrap;
    margin-top: calc(5 * var(--main-size));
    justify-content: center;
    align-items: center;
    margin-left: var(--nav-size);
    margin-right: 0;
}

.content div {
    width: 100%;
    text-align: center;
}