[SOLVED] Need some help in moving a tab right click context menu item to the bottom

I'm using this add-on to add a "Close Tabs to the Right" option. But after installing another add-on, the "Close Tabs to the Right" option isn't at the bottom anymore and I want to move it all the way to the bottom.

I searched and came across this guide to edit right click context menu items. However, I cannot get it to work.

This is what my userChrome.css looks like right now (scroll to the very bottom) https://pastebin.com/MWeTN19G

Here's the code I'm using to rearrange the tab context menu item

#_588c6fa6-14f9-4826-b769-71a305c80bbb_-menuitem-_close_right {
-moz-box-ordinal-group: 2 !important;
}

( I even tried setting -moz-box-ordinal-group to 2, 20, 200 but no luck)

This is the menu item id for the add-on's option I want at the bottom: _588c6fa6-14f9-4826-b769-71a305c80bbb_-menuitem-_close_right

This is the menu item id for the add-on that is currently at the bottom: _c2c003ee-bd69-42a2-b0e9-6f34222cb046_-menuitem-5

And also, I'm using Lepton to change the look of right click context menus, tabs, menu panels etc.

Here's a screenshot of the menu item ids

Edit:

#_588c6fa6-14f9-4826-b769-71a305c80bbb_-menuitem-_close_right {
order: 2 !important;
}

It works now.