Index: /trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSStyleSource.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSStyleSource.java	(revision 7073)
+++ /trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSStyleSource.java	(revision 7074)
@@ -52,4 +52,5 @@
     public final List<MapCSSRule> relationRules = new ArrayList<>();
     public final List<MapCSSRule> multipolygonRules = new ArrayList<>();
+    public final List<MapCSSRule> canvasRules = new ArrayList<>();
     
     private Color backgroundColorOverride;
@@ -86,4 +87,5 @@
         relationRules.clear();
         multipolygonRules.clear();
+        canvasRules.clear();
         try (InputStream in = getSourceInputStream()) {
             try {
@@ -144,4 +146,6 @@
                     multipolygonRules.add(optRule);
                     break;
+                case "canvas":
+                    canvasRules.add(r);
             }
         }
@@ -235,4 +239,6 @@
             if (((Relation) osm).isMultipolygon()) {
                 matchingRules = multipolygonRules;
+            } else if (osm.hasKey("#canvas")) {
+                matchingRules = canvasRules;
             } else {
                 matchingRules = relationRules;