Should have a reasonable login page.

[hunterhector]

Is your feature request related to a problem? Please describe.
The current login page is a very simple page without any style. We need to have a login page with som reasonable style.

Describe the solution you'd like
Adapt a style for the input page. Notably, center the form and make it clear for the users.

Describe alternatives you've considered
N/A

Additional context
N/A