Translation
:
Amongst other stuff, it's an attempt to make the web site a bit more "responsive" - meaning it automatically adjusts the layout, size and amount of information it shows to suit the size of the screen it's being viewed on. In other words, changes have been made to make the website more usable on small screen devices - otherwise known as phones.
At the moment, the post/thread display and forum listings have been changed - more major changes will happen later this year when I can get some serious time to look at it.
PS if you want to see what things look like on a phone then drag/resize your the browser window right/left edge to make it narrower and narrower - the layout will change as it gets smaller than about 800 pixels wide.