xmpp.chapril.org-conversejs/src/plugins/rootview/styles/root.scss

converse-root.converse-js {
    &.converse-fullpage,
    &.converse-overlayed,
    &.converse-mobile {
        bottom: 0;
        height: 100%;
        padding-left: env(safe-area-inset-left);
        padding-right: env(safe-area-inset-right);
        position: fixed;
        z-index: 1031; // One more than bootstrap navbar
    }

    &.converse-embedded {
        position: relative;
    }
}