Added preloader to hide elements before they are correctly rendered

src/web/stylesheets/utils/_general.scss

@@ -41,7 +41,7 @@ body {
 }
 
 .konami {
-    @include transform(180deg);
+    @include rotate(180deg);
 }
 
 ::-webkit-scrollbar {

src/web/stylesheets/utils/_mixins.scss

@@ -21,9 +21,40 @@
     user-select: $value;
 }
 
-@mixin transform($value) {
+@mixin rotate($value) {
     -ms-transform: rotate($value);
     -webkit-transform: rotate($value);
     -moz-transform: rotate($value);
     transform: rotate($value);
 }
+
+@mixin translateX($value) {
+    -ms-transform: translateX($value);
+    -webkit-transform: translateX($value);
+    -moz-transform: translateX($value);
+    transform: translateX($value);
+}
+
+@mixin translateY($value) {
+    -ms-transform: translateY($value);
+    -webkit-transform: translateY($value);
+    -moz-transform: translateY($value);
+    transform: translateY($value);
+}
+
+@mixin translate3d($x, $y, $z) {
+    -ms-transform: translate3d($x, $y, $z);
+    -webkit-transform: translate3d($x, $y, $z);
+    -moz-transform: translate3d($x, $y, $z);
+    transform: translate3d($x, $y, $z);
+}
+
+@mixin transition($value) {
+    -webkit-transition: $value; 
+    transition: $value;
+}
+
+@mixin animation($value) {
+    -webkit-animation: $value;
+    animation: $value;
+}

src/web/stylesheets/utils/_overrides.scss

@@ -118,4 +118,4 @@ optgroup {
 .colorpicker-color,
 .colorpicker-color div {
     height: 100px;
-}
+}