How can I center an inline div (not its content) using css?
VERY IMPORTANT: the width of the div is unknown (I can not specify it)
If by inline you mean, its CSS display property is set to inline
then you can center it by giving the immediate parent container a text-align:center
If you mean a div within another div, you can follow this approach if you can add a wrapper and float both:
How to horizontally center a floating element of a variable width?