Lato font resulting in incorrect *bold* on pages?

[choldgraf]

Over in Jupyter Book we got a report that for some Mac users, bold wasn't showing up properly on some browsers:

executablebooks/sphinx-book-theme#122

I think that this is because of the Lato font family that is loaded by default, because disabling it then makes the fonts look correct.

I'm wondering if this is something anybody has experienced with the pydata theme? I think Jupyter Book is getting its fonts straight from this theme, so if it's a bug there, it's probably a bug here. @hoetmaaiers maybe you have encountered something like this?

[hoetmaaiers]

HI @choldgraf , I did the same check on macOS in Safari. I do see Lato ren the <strong> text rendered in bold. I have no Lato installed on my system.

What browser appears to be the issue? Are we sure it is about Safari?

This screenshot does looks correct?

[jorisvandenbossche]

This might also be impacted by #169 ?

[jorisvandenbossche]

Now that #169 is merged, it might be good to test whether this changed / fixed anything. But @choldgraf I think you can't reproduce it yourself? (so testing might be a bit difficult, without waiting on the next release?)

[choldgraf]

digging into this a bit more, a few more pieces of information:

• The error is not Safari, I was mistaken. The error is on Chrome on OSX
• I can reproduce the error from within browserstack
• The issue seems to be that in Chrome on OSX, the Lato font is used. On Safari it is not used and defaults to the system sans-serif font (e.g. helvetica)
• So...it seems like the issue is that on most browsers, Lato isn't used. When Lato is used, this looks like a bug with Lato

That's a bit weird, because I'd assume that our explicitly-specified font we'd want to work the most, right?

I can confirm that on my own browser (W10, Chrome) from this page:

https://pydata-sphinx-theme.readthedocs.io/en/latest/demo/demo.html

Inspecting the bolded section shows that Lato is not being used and it's defaulting to the system sans-serif (Arial)

[jorisvandenbossche]

Thanks for digging in ..

On Firefox / Ubuntu, my web developer inspection tools indicate that Lato Bold is used for the bold word in the first sentence. But I am not sure how to actually check for sure

[hoetmaaiers]

In Chrome the error is indeed clearly printed in the console. Since #169 the Lato font is imported as a vendor font in which I am also able to reproduce the behaviour.

The issue is that the bold version lato-700.woff is not present, only the 400 version of Lato..

[choldgraf]

osed by #224