padding and margin changes to make www project page layout work without hacks; hack to position monitors correctly

src/css/units.css

@@ -1,3 +1,6 @@
+/* make sure to keep these in sync with other constants,
+e.g. STAGE_DIMENSION_DEFAULTS in lib/screen-utils.js */
+
 $space: 0.5rem;
 
 $sprites-per-row: 5;
@@ -9,6 +12,10 @@ $stage-menu-height: 2.75rem;
 $library-header-height: 3.125rem;
 $library-filter-bar-height: 2.5rem;
 
+$stage-standard-border-width: 0.0625rem;
+$stage-full-screen-border-width: 0.1875rem;
+$stage-full-screen-stage-padding: 0.1875rem;
+
 $form-radius: calc($space / 2);
 
 /* layout contants from `layout-constants.js` */