Graham bemethavinci Both html5 and css3 are browser based
html5 is just html and can be used in either code blocks or the pages html code as a whole
xtgem's standard blank page is a html5 page on most accounts (some may still use html4 default)
the same goes for css3 you just use it in your stylesheets or style attributes
its not a matter of xtgem supporting them
its a matter of whether the users or visitors device/browser supports them
I notice your page has a xml and xhtml !DOCTYPE (old wap phone header) not a html5 one which could possibly affect the way some browsers process the code