Hi,
I looked at your site from 2 devices and always saw just overlapping "mess".
Please take this only as a suggestion, I am not saying you should change it, but just think about it:
You are suggesting to press ctrl and zoom out the page. That surely "solves the problem", but...
Your goal was to have everything on one page without having to scroll. With pressing the CTRL key and then "scrolling" with the mousewheel, you are not saving the user any "work". But most importantly, you have to remember that the default zoom is the font size that is best for the user to read. If I zoom it out then yes, I do see the page like you want me to see it, but it is more or less useless. The font is so small that I have problems reading anything. And I cannot go back to the normal size because then everything is overlapping, so you are not giving me a choice.
There are several options how to really solve this.
First, probably the best, but also most difficult one in terms of coding, would be making it fully responsive by using various layouts based on user screen width. In other words adjust for example the number of columns and on smaller screens put the elements on top of each other rather than next to each other. This can be achieved by CSS and some Javascript and there are frameworks to make this easier for you such as Bootstrap.
The other option would be not using absolute positioning and use percentages for widths and for font sizes. And also make sure that the ideal view is on some relatively common monitor size. Do not make it look good just on the best HD monitor with HD resolution. Many people dont have that. If you make it look good on a smaller monitor, it will be usable on a wider one too, but not the other way around.
Only a suggestion