Update SCSS to module system (fixes #266)

Change-Id: I2387ef49dadaeac0f62620e0c803df12dad42cf8
diff --git a/dev/scss/main/plugin.scss b/dev/scss/main/plugin.scss
index 5b289a6..e0ac886 100644
--- a/dev/scss/main/plugin.scss
+++ b/dev/scss/main/plugin.scss
@@ -1,10 +1,13 @@
+@use "../base/colors";
+@use "../base/lengths";
+
 /**
  * Base rules for all plugin related styles,
  * like widgets.
  */
 
 div.view.widget {
-  padding-right: $right-view-distance;
+  padding-right: lengths.$right-view-distance;
 
   > iframe {
     margin:     0;
@@ -16,5 +19,5 @@
 }
 
 div.panel.result > div > div.widget > iframe {
-  background-color: $nearly-white;
+  background-color: colors.$nearly-white;
 }
\ No newline at end of file