_vendor-prefixes.scss in bootstrap-sass-3.3.0.0

- old
+ new

@@ -97,12 +97,15 @@
           hyphens: $mode;
 }
 
 // Placeholder text
 @mixin placeholder($color: $input-color-placeholder) {
-  &::-moz-placeholder           { color: $color;   // Firefox
-                                  opacity: 1; } // See https://github.com/twbs/bootstrap/pull/11526
-  &:-ms-input-placeholder       { color: $color; } // Internet Explorer 10+
+  // Firefox
+  &::-moz-placeholder {
+    color: $color;
+    opacity: 1; // See https://github.com/twbs/bootstrap/pull/11526
+  }
+  &:-ms-input-placeholder { color: $color; } // Internet Explorer 10+
   &::-webkit-input-placeholder  { color: $color; } // Safari and Chrome
 }
 
 // Transformations
 @mixin scale($ratio...) {