After ironing out some issues with my Twenty Fourteen Child Theme, I found another one. This one is not really a bug, as it is quite deliberate, but it was still a problem for my needs. When viewing a single post page, the secondary menu in the left sidebar is not visible. The menu is visible on other pages, and on the overall blog page. Again, I’m not sure why this was chosen behaviour, but there is a float left and negative margin that pushes the menu off the edge of the screen.
On line 3596 I changed the following:
#secondary { background-color: transparent; border: 0; clear: none; float: left; margin: 0 0 0 -100%; min-height: 100vh; width: 122px; }
To:
#secondary { background-color: transparent; border: 0; clear: none; position:absolute; min-height: 100vh; width: 122px; }
So far, this seems to have reinstated the menu, but I’ve yet to test this much yet. There is a chance it may cause trouble under certain conditions. I will see if it causes issues on a full-width page, and check the other media queries for knock-on issues.