Might be boring to you, but it isn't to us. This is (part of) our job :).
When I stopped to think about it, there was honestly no reason to not open source Primer. If the goal of open source is the share and learn and improve, then what does it matter what we release? Especially as open source?
Not to piss on the pie BUT: The GitHub CSS breaks when one sets a minimum font-size (as required for high DPI screens). Heck every web page based on bootstrap or most "modern" CSS frameworks breaks the same way.
How about you "CSS experts" get your shit together and start respecting the fucking standard. Assuming being able to force a font size (other than relative) is UNPORTABLE. It always has been and (hopefully) it WILL ALWAYS BE. I am NO GOD DAMN DESIGNER. I just know CSS because its fucking 2015. I knew this bug since fucking 2010. Only because I fucking PLAYED WITH CSS.
Why is that the GitHub (successful company, right?) CSS team makes mistakes I stopped making when I was in high school and CSS based layouts were a new thing?
Now wait for it: "But minimum font size is not a default setting in any browser. You're less than 1% of out userbase. We don't care."
/end unforgivable vulgar rant. No harm intended. Consider it comedy. But seriously: CSS people are so wrong right now. I should be the pope of web design and I don't even care about it.
mdo: It's not your fault. I am barking at the wrong tree. In fact there are more pressing issues I have that GitHub ignores. It just vulcanoed out of me. If you have any influence in the CSS scene, please try to address this common mistake.
At first glance I'd assume the idea is that a browser can choose to ignore author stylesheet font sizes if they are smaller than a certain size, ensuring text is always a minimum size of say, 16px. This is in contrast to approaches that vary the text size consistently -- either by scaling text alone to larger, constant sizes, or by using a "zoom" property. I can imagine that without JavaScript, a minimum font size would be harder to support and still maintain compatibility. This is why for most retina screen use cases, scaling is employed instead of font-size changes.
Getting back to minimum font size, I assume the point is that we shouldn't use em or rem to base our designs solely on font sizes, but instead on a combination of those and percentage-based units. Also, I imagine all layouts must "flow" to accommodate larger font sizes. Really, the biggest issue is that every browser and device supports "zoom" for text in different ways -- look at Android, for example -- and it's hard enough accommodating screen readers and multiple platforms to then take into account how browsers can change the page. To some extent, it's like complaining that your websites don't fit on my 800x600 CRT unless I make the text really tiny. Yes, it's a legitimate complaint, but maybe there's another browser out there or extension that can handle it -- e.g. "Readability" or Safari and how it can pull body text from a page. Or the ability to "zoom in" on sections of a page, e.g. with a magnifier.
It's a common(?) browser setting. E.g. in Firefox go to "Preferences > Content > Font & Colors / Advanced". It's useful for preventing websites from forcing font sizes that are too small for your display (e.g. in my case a 14" Full-HD panel).
Ideally no website would (1) change the base font size or (2) set fonts below 0.8em of base font size. Unless it intentionally wants unreadable text.
Alternatively I believe there are some high dpi related settings coming into the browsers to adjust the global "pixel size". That would "solve" the problem but really we shouldn't have been in this situation in the first place. Setting a pixel font size is just a stupid idea, obviously.
When I stopped to think about it, there was honestly no reason to not open source Primer. If the goal of open source is the share and learn and improve, then what does it matter what we release? Especially as open source?