I just noticed what I assume is another layout bug. When the browser width dips below about ~870 pixels the Room Key (listing of rooms) goes from two columns to one column, however the width of the column stays the same, so the rooms are only taking up the middle half of the page instead of going from left margin to right margin.
Fixing this in dungeon.css by adding the following line under the existing @media screen entry. (unlike my other fix, which is essentially a workaround, this is a permanent fix for this issue).
Code:
@media screen and (max-width: 870px) {
.room {width: 95%;}
}