incorrect removal of whitespace with 'px' and '+' in `max` (and probably `calc`)

[eoghanmurray]

(.virtual) :~/test$ pip install csscompressor
Collecting csscompressor
  Downloading csscompressor-0.9.5.tar.gz (237 kB)
...
  Created wheel for csscompressor: filename=csscompressor-0.9.5-py3-none-any.whl size=240407 sha256=c46201c4d27dfd191c24efc04cfe00367005d3b6799580bd09891e3eacacd103
...
Successfully built csscompressor
Installing collected packages: csscompressor
Successfully installed csscompressor-0.9.5

(.virtual) :~/test$  python
Python 3.13.3 (main, Aug 14 2025, 11:53:40) [GCC 14.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import csscompressor; csscompressor.__version__
'0.9.4'
>>> import csscompressor; csscompressor.compress('max(-8px, 12px + (800px - 100vw) / 30)')
'max(-8px,12px+(800px - 100vw) / 30)'

Note: I believe the library is incorrectly reporting an earlier library version; 0.9.4 instead of 0.9.5.

Expected output:
'max(-8px,12px +(800px - 100vw) / 30)'

The px+ is invalid CSS and causes the whole rule to fail in Firefox at least

Workaround is to do compressed_css = compressed_css.replace('px+', 'px +')