Autoprefixing and clean up

scss/base/_normalise.scss

@@ -1,7 +1,8 @@
-* {
-  -moz-osx-font-smoothing: grayscale;
-   -webkit-font-smoothing: antialiased;
-           font-smoothing: antialiased;
+*,
+*:before,
+*:after {
+  box-sizing: border-box;
+  font-smoothing: antialiased;
   text-rendering: optimizeLegibility;
 }
 

scss/generic/_mixins.scss

@@ -15,13 +15,6 @@
   font-size: #{$px / $base-font-size}rem;
 }
 
-@mixin background-size($size) {
-  -webkit-background-size: $size;
-     -moz-background-size: $size;
-       -o-background-size: $size;
-          background-size: $size;
-}
-
 @mixin placeholder {
   ::-webkit-input-placeholder {
     @content; 

scss/style.scss

@@ -9,9 +9,10 @@ Author: Mike Francis
 @import 'generic/reset';
 @import 'generic/utilities';
 @import 'generic/mixins';
+
 @import 'base/normalise';
 @import 'base/forms';
 @import 'base/grid';
 
 @import 'modules/nav';
-@import 'modules/buttons';
+@import 'modules/buttons';