How can I make a div not larger than its contents?

Question

I have a layout similar to:

I would like for the div to only exp

Answer 1

Tampering around with Firebug I found the property value -moz-fit-content which exactly does what the OP wanted and could be used as follow:

width: -moz-fit-content;

Although it only works on Firefox, I couldn't find any equivalent for other browsers such as Chrome.