CSS Dropdown Menu Breaks When Setting Left Property After Position Absolute - css

Question

I'm currently working on a CSS Dropdown menu and I've run into the following issues:
Each successive sub menu overlaps its parent menu by an increasing amount.
Attempting to fix item 1 by setting the left attribute (each submenu already has position:absolute) does not work and throws off the position of the menu wildly.
Whenever a submenu is shown, the right padding is automatically increased causing a gap between the menu and the bottom border of the menu items.
In the CSS I use display: table-* (the star being any of the table-related display values) in order to make vertical centering of text easier and to more easily keep the selected menu item at the top of the list (see display: table-header).
I would really like to know both solutions and causes for the above issues.
For reference, I've created a fully functional JsFiddle.

Answer 1

I made a fiddle here http://jsfiddle.net/xUWdj/
Changes made:
Got rid of all the table displays, the only reason you were using it was for vertical alignment, you can utilize line-height on the <a>'s instead.
All submenu <ul>'s now are positioned based off it's parent by left: 100%; & top: 0;
You should now be able to style/position the rest of the menu to how you want it.
Edit:
Here's a version that allows you to continue using the table-group-header http://jsfiddle.net/HSh5n/2/
Changed li a { display: block; line-height: 30px; }
Added margins to move the ul's to -42px 0 0 130px
I guess the biggest thing with tables is that since they're inline elements, you can't assign position: relative to table-cells, so that's why you couldn't use the left or top properties. I haven't browser tested this, but I'd always double check if you go this route.

Answer 2

If you add right border to your li a{...} you can get an idea about what's causing the overlaps.
li a {
display: table-cell;
border-bottom: solid 1px #cccccc;
border-right: solid 1px #cccccc;
text-decoration: none;
color: rgba(89,87,87,0.9);
height: 30px;
padding: 5px;
vertical-align: middle;
cursor: pointer;
}