Just CSS. Absolutely NO jQuery/javascript or any other programming language.

my original version of this demonstration was produce on the 23rd August 2008. CSS can come a long way since this demo.

Now that all the latest browsers support the new :is pseudo-class, I can convert my previous demonstration of tic-tac-toe so that the stylesheet is a little simpler.

The :is pseudo-class replaces the :matches / :any pseudo-classes.

Also note that the :not pseudo-class now accepts a list of selectors. This is not used in this demo, but in several of my previous demos the CSS can be compressed using a list of selectors.

Player starts first and plays noughts, the computer will then place its cross and the game continues until there is a winner or the game is drawn.

As with most games against the computer it is almost impossible to win, so in this version I have made it possible for you to win in two ways.
If you can follow the stylesheet you may be able to find these or you can just play the game and see if you can find them.

The stylesheet for this demonstration is in the page head, but if you use this, please keep my copyright comment with the stylesheet.

A donation for use of this demo would be appreciated.