Captive Portal Customization - Unifi Controller

Hi, I have a working Captive Portal (a simple one page html and CSS) and like to enhance this pages with the following features: 1. New CSS Design (nice modern look, transparent, new fonts, picture background, etc.) see screenshot 2. New page shall work for Desktop, Tablett and Mobile. (Adaptive design) 3. Simple customization of page components (Logo, Title, , background, Terms of use) of the portal 4. Multi-language: the few text phrases shall be available in different languages. User select language, Default language set by me (We do translation) The given code is a full working sample code from ubiquity. see [login to view URL] attachment Thanks!