Since we need to use number values for these breakpoints directly
in some places, having `px` values exported for them is not
great as we have to write weird looking code to convert it into
number.
On a high-DPI display or with a non-default zoom level, the browser
viewport may have a width strictly between md_max = 767px and md_min =
768px. Use only the *_min bounds for consistency.
This requires queries with strict inequalities to express upper
bounds (width < md_min). Fortunately, that functionality is provided
by range context queries. Unfortunately, those are not supported in
all browsers. Fortunately, we can compile them away using
postcss-media-minmax. Unfortunately, postcss-media-minmax currently
subtracts 1px for strict inequalities anyway to work around a Safari
rounding bug. Fortunately, 0.02px should be sufficient for that, so I
submitted a PR:
https://github.com/postcss/postcss-media-minmax/pull/28
Signed-off-by: Anders Kaseorg <anders@zulip.com>