Actualización

app/Resources/public/assets/modernizr/feature-detects/css-remunit.js

@@ -0,0 +1,19 @@
+
+// test by github.com/nsfmc
+
+// "The 'rem' unit ('root em') is relative to the computed
+// value of the 'font-size' value of the root element."
+// http://www.w3.org/TR/css3-values/#relative0
+// you can test by checking if the prop was ditched
+
+// http://snook.ca/archives/html_and_css/font-size-with-rem
+
+Modernizr.addTest('cssremunit', function(){
+
+  var div = document.createElement('div');
+  try {
+    div.style.fontSize = '3rem';
+  } catch(er){}
+  return (/rem/).test(div.style.fontSize);
+
+});