ie11fix.css

/*
* ============= Explanation for this file ===================
*   This file addresses an issue with ie11 in R presentation two-column mode.
*   Chrome (and, reportedly, Firefox) works fine, but ie11 looks really
*   weird: if there are code blocks or plots in two-column mode, 
*   they float on top of the slide title, occluding it (Paul Clark experienced
*   this first hand).
*
*   According to the author, the code below is from the "default css." 
*   Reportedly, the only change from the default was that
*   'position' was changed from 'fixed' to 'absolute'.  
*/

.reveal .slides section .column { 
  position: absolute; 
  width: 48%; 
  top: 2.5em; 
  bottom: 0; 
  margin: auto; 
 }