Update SCSS to module system (fixes #266)

Change-Id: I2387ef49dadaeac0f62620e0c803df12dad42cf8
diff --git a/dev/scss/main/introjs-ids.scss b/dev/scss/main/introjs-ids.scss
index 89496b1..44b3ff6 100644
--- a/dev/scss/main/introjs-ids.scss
+++ b/dev/scss/main/introjs-ids.scss
@@ -1,4 +1,5 @@
-@import "../util";
+@use "../util";
+@use "../base/colors";
 
 /**
  * Styles overriding introJS styles
@@ -21,5 +22,5 @@
 
 
 .tgreeting {
-    color: $darkest-orange;
+    color: colors.$darkest-orange;
     }