How to set image on foreground

I am using Sydney theme and I have some problem with setting on-click image on foreground. When I open full image top menu and other elements overlap it.
For example: here portfolio page with several images
When I click on any image it open full width on background:
How could I fix this problem?

P.S. if images didn’t open - you could check it on my sitepage

Hello Dmitriy,

Please try to use the following CSS code.

You can add CSS code to your site with Simple Custom CSS plugin (just copy CSS code and paste it in Dashboard → Appearance → Custom CSS after installing and activating the plugin). Also you can add CSS code directly to style.css file of your child theme.

body div#fancy_outer {
    z-index: 999 !important;

Kind Regards, Roman.