Mixed http / https content when accessing via https

I use ATA 3.7.15; site: goo . gl / qTO4Mc . When the site is accessed via https://, the theme still seems to include the files (css, js, images) via http; as a result the page is broken (unstyled) with IE 's warning "only secure content is displayed". Any advise?

I tried WP's default theme (twenty fourteen), it works properly via https.

I did find a workaround in a post #4 in http://forum.bytesforall.com/showthread.php?t=19840 :
I don't like this workaround because on a page accessed via http it includes all files (css, js, images) via https.