@function generate-width-classes($prefix, $steps, $unit) {
    $classes: ();
    
    @for $i from 1 through $steps {
      $width: $i * 0.4rem; 
      $class-name: #{$prefix}-#{$i};
      $classes: append($classes, (
        #{$class-name}: (
          width: $width,
        )
      ));
    }
    
    @return $classes;
  }
  
  $width-classes: generate-width-classes('w', 20, 'rem');
  
  @each $class, $props in $width-classes {
    .#{$class} {
      width: $props['width'];
    }
}