way to make the forum like the homepage of forumotion

[ariiki]

hello,

can anyone teach me how to make my forum like forumotion's homepage? (https://help.forumotion.com/)

and i'm pretty confused here.

spaces in the "site description" are limited so I can't really type much of the codes.
I've read through the .css file and i'm not quite understand with wat is written about it.
are we supposed to write codes in .html format using notepad and paste it at css sheet at colour ???