There some issues with forum styles on my Linux machine (Windows seems to be ok). Default (toxic light theme) works fine, any other causes layout problems (see screenshot).
4.4.0-112-generic #135-Ubuntu x86-64
Google Chrome Version 64.0.3282.140 (Official Build) (64-bit)
Firefox 58.0.1 (64-bit)
Questionable style lines inside
flex-direction: column; /* <= this one */
font-family: "Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
font-size: 0.875rem; /* <= font becomes unexpectedly small */
I have no idea how these styles been generated, but seems like there are some problems here.
UPD: cache cleaning doesn't help, as well as even browser changing.