IFrame completely closing the constructor's site

If you still don't know how to make an iframe that covers the entirety of the builder's site, here's an example from spai:

<iframe src="https://www.yandex.ru" frameborder="0″ style="overflow:hidden;overflow-x:hidden;overflow-y:hidden;height:100%;width:100%;position:absolute;top:0px;left:0px;right:0px;bottom:0px" height="100%" width="100%">