Microsoft’s ASP. Now it uses standard HTML 5 with CSS 3. The structure has undergone significant change. Evolved code, under any circumstances, ends up with idiosyncratic nooks and crannies that become a bugger to maintain and an even bigger bugger to replace (that’s a British bugger).
So the result of all of this is that, although the site has undergone major changes, there will be parts that are unintentionally broken. I haven’t repaired them because I haven’t found them. As I do so, I will fix the errors, but I apologise in advance for any you may encounter.