Enabling a popup from a boot window

I am creating popups with popover bootstrap option in interactive html creation. I first used the following tag:

<a class="btn popoverOption" 
   data-content="A group of people with a shared characteristic. It is an object of observation in epidemiological studies."
   data-original-title="cohort"
   data-placement="bottom"
   href="#"
   rel="popover"
   style="font-size: inherit; vertical-align: baseline; padding: 0; font: inherit;">
cohort
</a>

      

        
        
        
      

    

I deliberately made spces to show the syntax. The popup is below the text, so I tried to add data-container='body'

, but this way, when I enlarge the popup, it often goes off-screen. How can I get the popup to always stay on my screen (without fixing the size in any way, if possible)?

Thanks in advance! Please give me a call if I need to show more code, I haven't done so for brevity.