I made a powerpoint presentation & converted it to HTML at https://www.idrsolutions.com/online-powerpoint-to-html5-converter
The output html page on the mentioned site looks perfect for me.
But after I downloaded zip and put the contents on my new site (Ubuntu & PHP7 fresh install) I don’t see the blue background.
My site is https://castaneda.su/DK/221023
I tried to make these steps for my another site https://alpin52.ru/221023 (preconfigured by host provider) and the look is as required.
I think the problem is that I missed installing some component on the server. But I cannot figure out which. Thanks.