Cannot switch languages in Flamingo skin because document-header almost overlaps language buttons

If XWiki has multilanguage support and has language switch buttons, they are mostly overlapped by document-header, because in CSS file it has section .../skin/skins/flamingo/style.css
...
.document-header {
margin-bottom: 20px;
margin-top: -20px;
}
...
This negative margin overlaps language buttons almost entirely and user cannot switch languages on phone. (On computer, if width of window <1024px, and user know what languages are, he can move cursor on almost hidden buttons, but anyway it should be fixed).