Adding dynamic content from django templates with css

Question

Is it possible to add dynamic content with css? I'm having a button that shows/hides collapsible content and I would like to display on it "Show less" and "Show all X errors" where X is a number of errors. Right now I've got:

.collapsible_button:not(.active):after {
  content: '\02795   Show all errors';
  /* Unicode character for "plus" sign (+) */
  float: left; }

.banner .active:after {
  content: "\2796   Show less ";
  /* Unicode character for "minus" sign (-) */
  float: left; }

and

<button id="show_more" class="btn btn-secondary collapsible_button"></button>

But I would like something like:

content: '\02795   Show all {{ spreadsheet|length }} errors';

Is there a way to do this with scss only or I need to get js involved?