Add project files.

ConstructorAppUI/wwwroot/AdminTheme/build/scss/mixins/_toasts.scss

@@ -0,0 +1,23 @@
+//
+// Mixins: Toasts
+//
+
+// Toast Variant
+@mixin toast-variant($name, $color) {
+  &.bg-#{$name} {
+    background-color: rgba($color, .9) !important;
+    @if (color-yiq($color) == $yiq-text-light) {
+
+      .close {
+        color: color-yiq($color);
+        text-shadow: 0 1px 0 $black;
+      }
+    }
+
+    .toast-header {
+      background-color: rgba($color, .85);
+      color: color-yiq($color);
+    }
+  }
+}
+