    /**
     * @class Ext.tree.Panel
     */

    /**
     * @var {number} $tree-elbow-width
     * The width of the tree elbow/arrow icons
     */
    $tree-elbow-width: 16px !default;

    /**
     * @var {number} $tree-icon-width
     * The width of the tree folder/leaf icons
     */
    $tree-icon-width: 16px !default;

    /**
     * @var {number} $tree-elbow-spacing
     * The amount of spacing between the tree elbows or arrows, and the checkbox or icon.
     */
    $tree-elbow-spacing: 0 !default;

    /**
     * @var {number} $tree-checkbox-spacing
     * The amount of space (in pixels) between the tree checkbox and the folder/leaf icon
     */
    $tree-checkbox-spacing: 3px !default;

    /**
     * @var {number} $tree-icon-spacing
     * The amount of space (in pixels) between the folder/leaf icons and the text
     */
    $tree-icon-spacing: 3px !default;

    /**
     * @var {string} $tree-expander-cursor
     * The type of cursor to display when the mouse is over a tree expander (+, - or arrow icon)
     */
    $tree-expander-cursor: pointer !default;

    /**
     * @var {number/list}
     * The amount of padding to apply to the tree cell's inner div element
     */
    $tree-cell-inner-padding:
        top($grid-cell-inner-padding)
        right($grid-cell-inner-padding)
        bottom($grid-cell-inner-padding)
        0 !default;