Hi Ramya,
Could you please send a snapshot of the device screen somehow? (Taking a photo of the screen from your phone). As per my experience, this is possible to be achieved via the CSS file pixel settings.
For the second question, it is not necessary to default the user ID and password in SICF Logon Data. You can keep it blank. Also, make sure that you have done the settings as below:
It is imperative to keep Logon Procedure as 'Logon through HTTP fields' ONLY in case you are not using SSO or certificates.
Let me know.
Regards,
Utkarsha