Transparent background on spry menubar

Question

I've been trying to get a transparent background on my spry menybar submenus with little sucess.  Using alpha filters creates problems with ie and I can't get a transparent gif to work for some reason.
website here www.nathanielmcmahon.com
and the css
@charset "UTF-8";
/* SpryMenuBarHorizontal.css - Revision: Spry Preview Release 1.4 */
/* Copyright (c) 2006. Adobe Systems Incorporated. All rights reserved. */
LAYOUT INFORMATION: describes box model, positioning, z-order
/* The outermost container of the Menu Bar, an auto width box with no margin or padding */
ul.MenuBarHorizontal
    list-style-type: none;
    font-size: 100%;
    cursor: default;
/* Set the active Menu Bar with this class, currently setting z-index to accomodate IE rendering bug: http://therealcrisp.xs4all.nl/meuk/IE-zindexbug.html */
ul.MenuBarActive
    z-index: 1000;
/* Menu item containers, position children relative to this container and are a fixed width */
ul.MenuBarHorizontal li
    margin: 0;
    padding: 0;
    list-style-type: none;
    font-size: 100%;
    text-align: left;
    cursor: pointer;
    width: auto;
    float: left;
    position: relative;
    background-image: url(../assets/images/transbgd.gif);
/* Submenus should appear below their parent (top: 0) with a higher z-index, but they are initially off the left side of the screen (-1000em) */
ul.MenuBarHorizontal ul
    list-style-type: none;
    font-size: 100%;
    cursor: default;
    width: 8.2em;
    left: -1000em;
    position: absolute;
    z-index: 1020;
/* Submenu that is showing with class designation MenuBarSubmenuVisible, we set left to auto so it comes onto the screen below its parent menu item */
ul.MenuBarHorizontal ul.MenuBarSubmenuVisible
    left: 115px;
/* Menu item containers are same fixed width as parent */
ul.MenuBarHorizontal ul li
    width: 13em;
/* Submenus should appear slightly overlapping to the right (95%) and up (-5%) */
ul.MenuBarHorizontal ul ul
    position: absolute;
    margin: -27% 0 0 75%;
/* Submenu that is showing with class designation MenuBarSubmenuVisible, we set left to 0 so it comes onto the screen */
ul.MenuBarHorizontal ul.MenuBarSubmenuVisible ul.MenuBarSubmenuVisible
    left: auto;
    top: 0;
/* Menu items are a light gray block with padding and no text decoration */
ul.MenuBarHorizontal a
    display: block;
    cursor: pointer;
    padding: 0.5em;
    color: #999999;
    text-decoration: none;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 16px;
    font-weight: bold;
  background-image: url(../assets/images/transbgd.gif);
/* Menu items that have mouse over or focus have a blue background and white text */
ul.MenuBarHorizontal a:hover, ul.MenuBarHorizontal a:focus
    color: #999999;
/* Menu items that are open with submenus are set to MenuBarItemHover with a blue background and white text */
ul.MenuBarHorizontal a.MenuBarItemHover, ul.MenuBarHorizontal a.MenuBarItemSubmenuHover, ul.MenuBarHorizontal a.MenuBarSubmenuVisible
    color: #999999;
SUBMENU INDICATION: styles if there is a submenu under a given menu item
/* Menu items that have a submenu have the class designation MenuBarItemSubmenu and are set to use a background image positioned on the far left (95%) and centered vertically (50%) */
ul.MenuBarHorizontal a.MenuBarItemSubmenu
    background-image: url(../SpryAssets/SpryMenuBarDown.gif);
    background-repeat: no-repeat;
    background-position: 94% 50%;
/* Menu items that have a submenu have the class designation MenuBarItemSubmenu and are set to use a background image positioned on the far left (95%) and centered vertically (50%) */
ul.MenuBarHorizontal ul a.MenuBarItemSubmenu
    background-image: url(../SpryAssets/SpryMenuBarRight.gif);
    background-repeat: no-repeat;
    background-position: 94% 50%;
/* Menu items that are open with submenus have the class designation MenuBarItemSubmenuHover and are set to use a "hover" background image positioned on the far left (95%) and centered vertically (50%) */
ul.MenuBarHorizontal a.MenuBarItemSubmenuHover
    background-image: url(../SpryAssets/SpryMenuBarDownHover.gif);
    background-repeat: no-repeat;
    background-position: 94% 50%;
/* Menu items that are open with submenus have the class designation MenuBarItemSubmenuHover and are set to use a "hover" background image positioned on the far left (95%) and centered vertically (50%) */
ul.MenuBarHorizontal ul a.MenuBarItemSubmenuHover
    background-image: url(../SpryAssets/SpryMenuBarRightHover.gif);
    background-repeat: no-repeat;
    background-position: 94% 50%;
BROWSER HACKS: the hacks below should not be changed unless you are an expert
/* HACK FOR IE: to make sure the sub menus show above form controls, we underlay each submenu with an iframe */
ul.MenuBarHorizontal iframe
    z-index: 1010;
    position: absolute;
    filter:alpha(opacity:0.1);
/* HACK FOR IE: to stabilize appearance of menu items; the slash in float is to keep IE 5.0 from parsing */
@media screen, projection
    ul.MenuBarHorizontal li.MenuBarItemIE
        display: inline;
        f\loat: left;
        background: transparent;

Answer 1

Create a file to put your css values in (I'll call it "hello-world.css").
In hello-world.css put the following style:
.tab-pane *.tab-header-background
-fx-background-color: #00000000;
Add this to your code:
Scene scene = new Scene(root);
scene.getStylesheets().add(getClass().getResource("/hello-world.css").toExternalForm());
The code above will apply the style to all TabPanes in your scene. You also have the ability to apply the style only to a given instance CSS can by used to do that as well. There are others ways to accomplish the same thing. This way was more straight forward to me.