Please give a way to make hotspot page more customizable (ie: edit logo size, edit html structure, etc) and responsive.
The Hotspot feature built into the firewall itself is rather limited due to the webserver it shares with the firewall. There's a limited amount of space available to host that page, hence the limited options.
We do offer the ability to point to an external authentication page, which you can read more about here:https://www.watchguard.com/help/docs/help-center/en-US/Content/en-US/Fireware/authentication/hotspot_external_guest_auth_about_c.html
Pointing to an external page would allow to you edit the webpage however you like.
WatchGuard Customer Support
is there any example page?
I would suggest reading the full articles so you fully understand what you need to configure, but the page I linked above links to other articles that provide an example:
(Configure a Web Server for Hotspot External Guest Authentication)https://www.watchguard.com/help/docs/help-center/en-US/Content/en-US/Fireware/authentication/hotspot_external_web_server_config_c.html
(Hotspot External Guest Authentication Example)https://techsearch.watchguard.com/KB/?type=KBArticle&SFDCID=kA2F00000000LHTKA2&lang=en_US
i dont understand if i need to write, in an external web server, the code to autenticate the user. I want only to have a different layout for the login page, living all the autenthication user/logic in the firebox
You would need to write the entire page if you used an external server.