Where change CSS of reset password page

rg90

Hi i try more than hour find CSS of reset page (where user can reset password)

I try add any styles in CSS in administration or i try add i to admin.less so nothing change.
I try clear cache in administration in browser.. nothing

I try change .form .button { and .button {

I would like to welcome more advanced color change options in Flarum than just the two main ones :-)
Thank you for your help.