How to use in a SASS file a var() in a condition?

Question

I get a data from my HTML and I need to check if this data is inferior to 50, in my SCSS file. But I can't use my var() with a condition. Later this data will become dynamic, that's why I decided to use variable.

HTML:

<div class="pie-wrapper progress-ventilation" style="--progress: 95;"></div>

SCSS:

        @mixin draw-progress($progress) {
          .pie {
            .left-side {
              transform: rotate(calc(#{$progress} * 3.6deg));
            }
    
            @if $progress <= 50 {
              .right-side {
                display: none;
              }
            } @else {
              clip: rect(auto, auto, auto, auto);
    
              .right-side {
                transform: rotate(180deg);
              }
            }
          }
        }

        &.progress-ventilation {
          $progress-ventilation: var(--progress);
          @include draw-progress($progress-ventilation);
        }

I tried :

        @mixin draw-progress($progress) {
          .pie {
            .left-side {
              transform: rotate(calc(#{$progress} * 3.6deg));
            }
    
            @if calc(#{$progress} <= 50) {
              .right-side {
                display: none;
              }
            } @else {
              clip: rect(auto, auto, auto, auto);
    
              .right-side {
                transform: rotate(180deg);
              }
            }
          }
        }

        &.progress-ventilation {
          @include draw-progress(var(--progress);
        }