Div collapse after float css

Question

I have a div called NAV and inside of NAV I have an UL with 5 li which I float to the left, the li's that is but when I do that the NAV collapses. I know this because I put a border around NAV to see if it collapses and it does. Here is the example.

collapsed http://img401.imageshack.us/img401/8867/collapsedze4.png

no collapsed http://img71.imageshack.us/img71/879/nocollapsedkx7.png

as you can see in the first image, the links in the NAV div are floated left and that black border ontop is the actual div called NAV.

in this image you can see how it has top and bottom border and it not collapsed.

here is some of the html and css I used.

alt text http://img301.imageshack.us/img301/5514/codejc8.png

#nav #ulListNavi  a  {
    float: left;
}

Answer 1

A few other options for clearing floats here:

http://www.quirksmode.org/css/clearing.html

http://www.sitepoint.com/blogs/2005/02/26/simple-clearing-of-floats/

As to the best way of doing it, that's almost a holy war, the purists would freak about the extra div, if you are not fussed by a little extra markup, the addition of the cleared div as suggested by Joshua and AJ will work fine, and is a reliable technique, but there are at least 17 other ways of doing it...

Answer 2

The quickest solution would be to add overflow:hidden to clear the float on the parent element:

#nav{overflow:hidden;}

Answer 3

Without changing your HTML:

#nav
{
    width: 100%;
    overflow: auto;
    border: solid 1px red;
}
#ulListNavi
{
    margin: 0;
    padding: 0;
    list-style: none;
}
#nav #ulListNavi li
{
    float: left;
}
#nav #ulListNavi li a
{
    margin-left: 5px;
}

Works in IE8 and FF 3.5

Answer 4

Add any overflow value other than visible to your container:

div#nav { overflow:auto; }

Then add width to restore the width

div#nav { width: 100%; overflow:auto; }

Answer 5

Don't bother with clearing elements or overflow. Add this:

#nav {
    float: left;
}

When you float the LI's, the #nav no longer "contains" anything so it collapses. But if the #nav is floated also, it contains anything floated inside it, so it expands again.

(Also consider removing the #nav div and just applying the same styles to the UL.)

Answer 6

add this code after your ul:

<div style="clear: both"></div>