Adding html tag above shiny secure app login page

I have used shinymanager to add an authentication page to my shiny application. The authentication page looks as follows: current problem. I would like to add html tags (e.g. a header) over and outside the borders. I have used the tags_top argument without any luck (it places the element inside the box).

ui <- secure_app(ui,          
                 tags_top = 
                   tags$div(
                     tags$h4("This should be over the login widget, outside the box;"),
                   
                   )
) 

How can this be solved? I will consider also solutions based on css, as long as they remain effective for multiple screens. For instance, my current attempt is problematic for different screens. I also tried position:absolute, top:0 without any results.

ui <- secure_app(ui,          
                 tags_top = 
                   tags$div(
                     tags$h4("I want this header tag to be outside the login widget, over the borders of the box.",style="align:center;position:relative;top:-80px;margin:0"),
                     
                   )
)