Board Thread:Support Requests - Designing Your Wiki/@comment-25714421-20170730144102/@comment-9605025-20170730224154

First, I would like to modify TableWiz's response. Since your wiki is new, you should place the CSS TableWiz suggested at MediaWiki:Common.css instead of MediaWiki:Wikia.css. For an explanation of why, see Help:Community_CSS_and_JS. Also, inclusion of the query string ( ?cb=20170605111304 ) in the image URL is not necessary. Using, in TableWiz's example, https://vignette3.wikia.nocookie.net/tma/images/5/50/Wiki-background/revision/latest is sufficient and will allow you to update the image in the future if you wish without needing to update the CSS.

As a side note, per TableWiz's instructions, it is recommended that you upload the image to your wiki. This ensures that it will remain available for you to use. However, this step is not strictly necessary. If the image is hosted somewhere else online, you could get away with using that URL instead. However, doing so is considered a bad practice.

Second, here is a reference for the text shadowing (https://www.w3schools.com/cssref/css3_pr_text-shadow.asp). It is accomplished using CSS. Since English is not your native language, feel free to ask questions if you don't understand what the page is saying.