IE11 doesn't see classes starting with "--". How to fix?

Question

css

Good afternoon. I use Sass + BEM. I make modifiers context-sensitive, for example The same "--size_big" modifier can change the properties of another block/element differently. Already used to it, no need to drag a footcloth from the name of the block / element. Question - IE11 does not see classes starting with a double dash, everything is ok in chrome. How to fix? Replace double dash with another character?
<p class = "title --size_big">

Answer 1

Double hyphen is used in custom properties (css variables)
It is strongly discouraged to use classes starting with double hyphen.
PS.
Why not use BEM in a human way, like everyone else?

<p class = "title title_size_big">
</p>

firstly, there are no conflicts,
and secondly, other developers will not have to rack their brains about what the hell is BEM like here ...