Why for li with style float:left browser evaluates the height of the ul element to 0?

Question

In the code presented on the gist : https://gist.github.com/1341600 I am trying to use ul/li elements for grouping together some search form elements (instead of table). When in

Answer 1

Add following css:

ul.search-inputs {
    overflow: hidden;
}

Also see this jsfiddle.