Great job on making Core responsive.
There's just a few little things that could be fixed (I don't know if these are part of Core or part of XF though). I can post screenshots tonight to explain better.
1) When going to a small browser window the sidebar drops below the node list but it doesn't expand to the same width (it's slightly less) until you go to an even smaller browser window when it then actually expands to match the width of the node list.
2) The Advanced footer doesn't go responsive very elegantly with some parts pushed below and then no longer aligned. I'd suggest as soon as the page is too narrow for the 3 panel footer, to push it so it's only 1 panel wide and all 3 are below each other.
3) When using the User Bar, below a certain width the account options all disappear (they actually drop to a new line and are hidden). I imagine a longer username makes this worse. I think you need at least a dropdown icon to remain in the top right whatever the resolution is. i.e. Inbox and Alerts can both go if it gets really narrow but turning the username into an icon and having it link to index.php?account is fairly vital.
There's just a few little things that could be fixed (I don't know if these are part of Core or part of XF though). I can post screenshots tonight to explain better.
1) When going to a small browser window the sidebar drops below the node list but it doesn't expand to the same width (it's slightly less) until you go to an even smaller browser window when it then actually expands to match the width of the node list.
2) The Advanced footer doesn't go responsive very elegantly with some parts pushed below and then no longer aligned. I'd suggest as soon as the page is too narrow for the 3 panel footer, to push it so it's only 1 panel wide and all 3 are below each other.
3) When using the User Bar, below a certain width the account options all disappear (they actually drop to a new line and are hidden). I imagine a longer username makes this worse. I think you need at least a dropdown icon to remain in the top right whatever the resolution is. i.e. Inbox and Alerts can both go if it gets really narrow but turning the username into an icon and having it link to index.php?account is fairly vital.