Not sure what that other guy is talking about. CSS by itself is not the best thing to go with. That does not make sense. You can do nearly all of this with a WordPress site. That part he did get right. Some of these things you can do through plugins, but to get it looking exactly like you have pictured in your head, you may need some of it to be custom coded by somebody. Drupal tends to be more flexible for developers as well as Joomla. They have a higher learning curve though so are harder to learn. I would suggest making sure something like this does not already exist as well. Once you are sure it does not, do a bit more research on CMSs.
Wordpress is more widely used and has more available plugins. Drupal and Joomla are harder to learn but better for developers (which may be required for more custom stuff).
FYI: [NASA.gov](https://NASA.gov) and [UFC.com](https://UFC.com) both use Drupal and are highly custom sites.