#2000 CSS errors with semantic-ui

[Archimedes Trajano]

When using Semantic UI CSS https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.4.0/semantic.min.css I get errors

2018-11-16 20:09:07 WARN DefaultCssErrorHandler:41 - CSS error: 'https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.4.0/semantic.min.css' [27:385] Error in expression. (Invalid token " ". Was expecting one of: <number>, "inherit", <ident>, <string>, <hash>, <ems>, <exs>, <length_px>, <length_cm>, <length_mm>, <length_in>, <length_pt>, <length_pc>, <angle_deg>, <angle_rad>, <angle_grad>, <time_ms>, <time_s>, <freq_hz>, <freq_khz>, <resolution_dpi>, <resolution_dpcm>, <percentage>, <dimension>, <unicode_range>, <uri>, <function>, "progid:".)</function></uri></unicode_range></dimension></percentage></resolution_dpcm></resolution_dpi></freq_khz></freq_hz></time_s></time_ms></angle_grad></angle_rad></angle_deg></length_pc></length_pt></length_in></length_mm></length_cm></length_px></exs></ems></hash></string></ident></number>

Looking at it, it appears it is because of calc with margin:calc(2rem - .14285714em)

I think it may be that .14285714em is not recognized as ems.