The picture looks similar to what the legacy wikis look like when CSS isn't loaded. Perhaps it is just an issue with the browser having issues with the CSS? How many other things do you have running when you try to access the page?
The at-import doesn't change anything. All it does is make the font available for use in other parts of the CSS. You choose where the font is applied the same way you choose for any CSS; with the selector portion of the CSS rule.
It doesn't have to be on the school network. They could have some ad-blocker or website blocker program running.
Then the school probably has some sort of internet filter that is blocking the content.
Just because other wikis do it doesn't mean it is allowed. Per the customization policy CSS customizations must be restricted to the right rail and the main article area. That said, you probably won't get into any serious trouble for it either.
I am not sure what you are asking in your question. The CSS gets applied to the header because of the selector that you used.
Well, we don't know for sure if that is the cause but the timing is oddly coincidental.
I have uploaded a larger version of the image (here). You can download it and re-upload it via ThemeDesigner. It should be large enough to get the "no-split" option.
Well, the one that appears last in the CSS is the one that should be applied to the header. But just FYI, both are violating the customization policy.
Fandom has been having server issues over the past few months. The one you listed is one of the errors that user have occasionally encountered. There isn't much you can do besides wait and try again. As for the cause of the carious errors, Fandom isn't saying.
Is this happening on all wikis or just some? If just some wikis, which ones? Which editor are you using?
You can request (using the link that Headquarter8302 provided) that Fandom move your wiki to an earlier batch of migrations but they may or may not agree to do it.
Which wiki is this for?
You have to copy the CSS as well. Also, on the Rise of Nations Wiki, you may want to clean-up the CSS imports a bit. One of the main points of using load.php is to load everything in one request but you have separate requests for each stylesheet right now.
For the purposes of being as transparent as possible, it is best practice to clearly identify the alt account as such on its user page.
Fonts don't just magically work on websites. Either the viewer has to have it installed on their device or the website was to provide the font file. Web-safe fonts are fonts that are so common on devices that it is likely the viewer has it. However, even web-safe fonts are not guaranteed to work unless the website provides the font file.
I remember someone else asking about this. The mode parameter is from base MediaWiki not the galleries that were ported from the legacy platform. Based on what I recall and what the other user said, I believe it did work on UCP for a while but apparently it isn't anymore. I suggest you contact staff and ask them about this.
In the mean time, you can report vandalism to SOAP.
They are the wikis for which announcements will be auto-dismissed. They will still show in your notification list but they will already be marked as read. On legacy wikis, the unread count will be updated accordingly but that part of the script doesn't work on UCP yet. As for other types of notifications, they will not be auto-dismissed even if they are from those wikis.