This video shares how to customize the background image and login pages of an app.
Here is the code used for customizing the logo and background:
span.t-Login-logo {
background-image: url(#WORKSPACE_IMAGES#Oracle_AutonomousDatabase_rgb.png);
background-size: contain;
width: 260px;
height: 150px;
background-position: center;
}
.t-PageBody--login {
background-image:url(#WORKSPACE_IMAGES#redwood-abstract-bg.jpg);
background-repeat: no-repeat;
background-size : cover;
background-position: center;
}