fix #1303 - wrong color when hovering over "selectgroup" in dark mode

src/scss/layout/_dark.scss

@@ -102,7 +102,6 @@ body:not(.theme-dark) .hide-theme-light {
   .form-select,
   .form-file-text,
   .form-control,
-  .form-selectgroup-label,
   .form-selectgroup-check,
   .form-imagecheck-figure:before {
     background-color: $dark-mode-darken;

src/scss/ui/forms/_form-selectgroup.scss

@@ -50,7 +50,7 @@ Select group
   }
 
   &:hover {
-    color: $body-color;
+    color: var(--#{$prefix}body-color);
   }
 }