While it is not strictly needed. You will need to check all styles code in order to work.
Sliders are made to work with Headspin Copilot plugin which you could get for free.
Headspin Copilot is small design system builder. That means everything that we create will be styled in few clicks. Over 1000 users are using that system, it won't lock your site, and you could use it for free.
If you are advanced user, it supports pluginless mode also, where you would use plugin to build styles and later include these styles with small PHP code.