Change mathjaxr font family in Shiny app

[Minh96]

I am just wondering if it is possible to change the font family in mathjaxr equation, ideally I want to have it changed to monospace. I have tried changing this in css but it still doesn't work. It could be because I have the wrong class specified.

style.css

div.MathJax_Display{
   text-align:center !important;
   font-family:monospace !important;
}
.MathJax body{font-family:monospace;}

SERVER.R

observeEvent(input$calculation,{
  createAlert(session, anchorId = "percentage", alertId = "Alert4", title = "<center><font size='20px'>IMPORTANT</font></center>",
              content = HTML("<div class=alert alert-info, role=alert style='color:black;font-family:monospace;'>
                      $$\\textrm{one} = \\frac{53.2 \\times \\textrm{two}}{\\textrm{three}}$$<script>MathJax.Hub.Queue(['Typeset', MathJax.Hub]);</script>"), 
              append = FALSE, style = "info")
  jqui_draggable(selector = '.alert-info')
})

OUTPUT

Any help would be greatly appreciated.

Many thanks