@mixin appearance( $what ) {

    // Widget
    @if ( $what == widget ) {
        @include appearance_widget;
    }

    // Panels
    @if ( $what == panel ) {
        @include appearance_panel;
    }
    @if ( $what == popup ) {
        @include appearance_popup;
    }


    // Header
    @if ( $what == header ) {
        @include appearance_header;
    }
    @if ( $what == hovered-header ) {
        @include appearance_hovered-header;
    }
    @if ( $what == selected-header ) {
        @include appearance_selected-header;
    }


    // Button
    @if ( $what == button ) {
        @include appearance_button;
    }
    @if ( $what == hovered-button ) {
        @include appearance_hovered-button;
    }
    @if ( $what == pressed-button ) {
        @include appearance_pressed-button;
    }
    @if ( $what == focused-button ) {
        @include appearance_focused-button;
    }


    // Primary button
    @if ( $what == primary-button ) {
        @include appearance_primary-button;
    }
    @if ( $what == hovered-primary-button ) {
        @include appearance_hovered-primary-button;
    }
    @if ( $what == pressed-primary-button ) {
        @include appearance_pressed-primary-button;
    }


    // Toolbar
    @if ( $what == toolbar ) {
        @include appearance_toolbar;
    }


    // Input
    @if ( $what == input ) {
        @include appearance_input;
    }
    @if ( $what == hovered-input ) {
        @include appearance_hovered-input;
    }
    @if ( $what == focused-input ) {
        @include appearance_focused-input;
    }


    // Node
    @if ( $what == node ) {
        @include appearance_node;
    }
    @if ( $what == hovered-node ) {
        @include appearance_hovered-node;
    }
    @if ( $what == selected-node ) {
        @include appearance_selected-node;
    }


    // List item
    @if ( $what == list-item ) {
        @include appearance_list-item;
    }
    @if ( $what == hovered-list-item ) {
        @include appearance_hovered-list-item;
    }
    @if ( $what == selected-list-item ) {
        @include appearance_selected-list-item;
    }
    @if ( $what == focused-list-item ) {
        @include appearance_focused-list-item;
    }

}