Custom sign in page with Azure ADFS SSO authentication

I have an MVC  5 application that lets users Single Sign On using Azure ADFS.  Currently, when users first navigate to the application site, they see the Azure Portal login page (SSO) as default.  That is not what our company wants.  We would like theorder of user log in process like:   

First, users should see our own company custom themed page. In that custom themed page, there are some custom logos and company business texts and aLog-In button.  When the Log-In button is pressed, users should see the Azure Portal login page (SSO) and log in from there.

Please give me some ideas how to achieve so.  Thank you  in advance.