Long site titles break navigation on mobile devices

[rjzupkoii]

This is related to #1387, but long site titles break masthead / navigation on mobile devices. Can be reliably reproduced by setting title to a 60 character string in _config.yml and switching to a mobile view in Chrome.

[rjzupkoii]

Restricting the text via max-width seems to help, but isn't a complete fix since there's still overlapping text present which can cause navigation issues.

[rjzupkoii]

Shifting to the next milestone since this appears to be a bit of an edge-case as well.