Custom password reset flow

[kiran.ms]

thanks @john.gateley

We are currently using the API “/dbconnections/change_password” to reset the password.
I know that we can customize the email template.
But where & how we can customize:

1. The page which opens when the link in email is clicked
2. The success message popup
3. The error message popup
4. Put additional data validation in this page - to check custom password policy. Password check against a regular expression or a custom javascript code.

We need the exact look and feel like this