Windows Search is one of the flagship features of Windows 10 and it allows you to search for your local files and web (Bing) Windows Search interface is based on Microsoft’s web technologies, it can be easily tweaked by injecting a custom JavaScript file. If you don’t want to do this manually, you can use an open-source free tool called “BeautySearch”” to tweak the look and feel of the search results. BeautySearch also allows users to enable dark mode within the results page. The other features include: Add shadows to context menus and acrylic effect to the context menus.”
Source: https://www.bleepingcomputer.com/news/microsoft/how-to-beautify-the-windows-10-search-feature/