FIX Error: Cannot divide by "px", number expected by "yarn encore prod"

FIX generated error by "yarn encore prod" cmd in ibexa/commerce v3.3.22 and nodejs v14.0.0 postcss "^7.0.0" postcss-calc "^7.0.1"

yarn run v1.22.4
$ /var/www/html/project/ezplatform/node_modules/.bin/encore prod
Running webpack ...

I 1185 files written to public/assets/build
Error: Cannot divide by "px", number expected
at /var/www/html/project/ezplatform/ezplatform-admin-ui-content-edit-parts-css.4f0325aa.css:804:3

src/bundle/Resources/public/css/enhancedimage-field.scss

@@ -16,7 +16,7 @@ $ibexa-color-font: #131c26;
 
 $ibexa-border-radius: calculateRem(2px);
 
-$base-font-size: 16px;
+$base-font-size: 16;
 
 @function calculateRem($size) {
     $remSize: calc(#{$size} / #{$base-font-size});