Board Thread:Support Requests - Designing Your Wiki/@comment-44745594-20200927035923/@comment-9605025-20200927221431

You wanted to adjust the background size so it appears similar for all screen sizes. HumansCanWinElves's proposed solution is to just set the width to whatever it needs to be to fit the different screen sizes by using @media to set different widths for different screen sizes. The size of the element you are placing the background in depends on the size of the screen so in order to do that you need to know what the size of that element is on different screens. The CSS I pasted above is Fandom's current global UCP CSS that dictates what those sizes are. By looking at the above CSS, you can calculate the size of the target element and set the background size accordingly.