Hi!
Sorry my English... (By Google):

I'm using iframe on my website, as follows:
On top, a player of is used in another iframe below, the website is located.

<iframe 1 player>
<iframe 2 website>

The problem is located, that when the site is open through the iframe, css3 does not work (border, background, nothing)

but when I open the site outside of the iframe, the effects usually appear, can anyone help me?

thanks!

make sure the call to pie is relative to your iframe page.
also make sure your iframe page has the call or if you are using an external css file, make sure it's a relative path to the iframe page.
I use iframes with pie on hundreds of sites and it works fine for me.