The padding declarations are back and the height declaration is gone.
What went "south":
This is no unusual behavior. It is because the List Items are "floats" and floats do things like that. They are out of the flow, they just float there. So because the List has nothing to contain, it collapses. Its bottom border is all that we can see, it is flush with the yellow box. For the same reason, the following element (H2) containing the text "General Rules" moves up to "keep up" with the List. The space in between the 2 elements is the same as on the previous page; it corresponds to the default margin of the H2. This text comes to position itself right past the last Tab - which is the last float.
IMPORTANT things to consider: if you look at page 1 ("out of the box") in a very narrow viewport, you'll notice that the Tabs get stack on top of each others and that the following element in the document flow does not appear below the last Tab but next to it, like in this page (next page addresses that issue). To prevent that following element to shift right, you need to style it like this: "clear:left".
To prevent the Tabs to collapse: declare a fixed with for the Navigation Menu. For example the Menu at the top of these pages uses the following rule: #TJKul {width=500px}
Next page:
body {background-color:#fff;padding:20px} h1,h2 {font-size:1.1em;border-bottom:1px dotted #999}
#TJKul,#TJKul li {margin:0;padding:0;list-style:none} #TJKul,#TJKul li,#TJKul a,#TJKul span {height:1.6em;line-height:1.6em} #TJKul {border-bottom:1px solid #333;background-color:#ffcccc;padding-left:40px} #TJKul li {float:left;width:auto;position:relative;white-space:nowrap} #TJKul a {position:relative;text-decoration:none} #TJKul a:hover {background-color:transparent} #TJKul a,#TJKul a span {padding-top:.7em;padding-bottom:.2em} #TJKul a span {padding-right:10px} #TJKul #current a,#TJKul #current a span {padding-top:1em;border-bottom:2px solid #fff;font-weight:600} #TJKul #current a span,#TJKul a:hover span {background-image:url(up.gif)} #TJKul .TJKL,#TJKul .TJKR {background-image:url(down.gif)} #TJKul .TJKL {background-position:top left} #TJKul .TJKR {background-position:top right}
#TJKul #current a {padding-top:.1em} #TJKul a span {padding-top:.3em} #TJKul a {cursor:hand;margin-bottom:-.7em}