anchor.diff:              | Tab.Props props -> { result with Props = props }
               | Tab.IsActive state -> { result with IsActive = state }
               | Tab.CustomClass customClass -> { result with CustomClass = Some customClass }
  +            | Tab.Modifiers modifiers -> { result with Modifiers = modifiers |> parseModifiers }
   
           let opts = options |> List.fold parseOptions Tab.Options.Empty
  -        let classes = Helpers.classes "" [opts.CustomClass] [Classes.Tabs.Tab.State.IsActive, opts.IsActive]
  +        let classes = Helpers.classes "" (opts.CustomClass::opts.Modifiers) [Classes.Tabs.Tab.State.IsActive, opts.IsActive]
           a (classes::opts.Props) children
   
       /// Generate <span class="panel-icon"></span>
       let icon (options: GenericOption list) children =
           let opts = genericParse options
  -        let classes = Helpers.classes Classes.Block.Icon [opts.CustomClass] []
  +        let classes = Helpers.classes Classes.Block.Icon (opts.CustomClass::opts.Modifiers) []
           span (classes::opts.Props) children
  
positive.code:             /// Add `is-active` class if true
              | IsActive of bool
              | CustomClass of string
  
          type internal Options =
              { Props : IHTMLProp list
                CustomClass : string option
                IsActive : bool }
  
              static member Empty =
                  { Props = []
                    CustomClass = None
                    IsActive = false }
  
      module Tab =
  
  
negative.code:             /// Add `is-active` class if true
              | IsActive of bool
              | CustomClass of string
              | Modifiers of IModifier list
  
          type internal Options =
              { Props : IHTMLProp list
                CustomClass : string option
                IsActive : bool
                Modifiers : string option list }
  
              static member Empty =
                  { Props = []
                    CustomClass = None
                    IsActive = false
                    Modifiers = [] }
  
      /// Generate <div class="panel-block"></div>
      let block (options : Block.Option list) children =
  