That does even happen on larger viewports, if the name of the
function is long enough, see, for instance
<http://php.net/manual/en/function.geoip-continent-code-by-name.php>.

It's caused by an overflow:hidden, see
<https://github.com/php/web-php/blob/master/styles/theme-base.css#L331>.
Is there a particular reason to have this overflow:hidden for all
headings? Otherwise I suggest to remove or override it, and maybe
to add word-wrap:break-word.

The overflow:hidden was originally there to avoid the headerbackground from leaking into Change language section. Note that while the background has been removed the border is still there and "leaks" into the Change language content.

My preferred way to fix this situation would be to remove the overflows, etc, on the headers and only show the Change language options at that location on small screens. On sufficiently large screens it would go into the sidebar above the related functions sections. See http://imgur.com/a/1Hvax#0

Excuse me, in that last post I said:

> Note that while the background has been removed the border is still there and "leaks" into the Change language content.

It should have read:

> Note that while the background has been removed the border is still there and would leaks into the Change language content if we remove overflow:hidden.

Still a problem. We don't care? It's annoying and SO easy to fix! Function over form, right? Just make it work, we'll take the 1cm extra scroll.

Your pull request fixing this is welcome at https://github.com/php/web-php.