CSS: Fix Bootstrap 4 grid system for Safari

Close #690
Also, see #571

layouts/partials/css/academic.css

@@ -8,18 +8,6 @@
  *  Core
  **************************************************/
 
-*,
-*::after,
-*::before {
-  box-sizing: border-box;
-}
-
-.row:after,
-.row:before {
-  content: " ";
-  display: table;
-}
-
 html {
   font-family: '{{ .Get "body_font" }}', sans-serif;
   font-size: {{ .Get "font_size_small" }}px;