Shifting the technology tree away from the floating menu. #26

Hi! I was parsing the interface on different devices and noticed that when the page is compressed on the sides (for example, when viewing on a smartphone), the floating menu moves some of the buttons to a new line, which causes the technology names in the top nodes to overlap.
I found out experimentally that changing the <div id="tech-tree" style="margin-top:50px"> property in /assets/html/body.html from 50px to 75px solves the problem perfectly.