Please be more specific.

What do you mean that Mozilla or Chrome doesn't support CSS or PHP? Both browsers support CSS and PHP.

Is it one Website that you are checking or is it all Websites?

Please explain exactly what you mean.

Check your browsers updates, all those browsers you mentioned are fully ready to support any website's codes !!
or clarify your question more better

Mozila and google chrome both support css, php. There is a problem elsewhere. Tell the problem in detail.

Hi
I think Both browsers support CSS and PHP. Please use update version of mozila or google chrome. Then your problem would be solved.

Hi,

I agree with Fredbou. If you explain exactly what do you mean. Mozila and Chrome supported css, php. Please update your browser. I hope your problem will be resolved.

Thanks

Check your browser up to date or not if your browser updated then you have need to changes some settings of your browser.

Php is a server side scripting language which isn't executed on client side (browser). If you are unable to view any webpage, there might be something wrong with you browser settings like javascript disabled or any malicious extension, add-on. Please reset the browser settings and if the problem still persist, you may want re-install the browser.