diff --git a/engine-proto/ConstructionViewer.jl b/engine-proto/ConstructionViewer.jl
index efa7293..563857a 100644
--- a/engine-proto/ConstructionViewer.jl
+++ b/engine-proto/ConstructionViewer.jl
@@ -3,7 +3,7 @@ module Viewer
 using Blink
 using Colors
 
-export ConstructionViewer, display!
+export ConstructionViewer, display!, opentools!, closetools!
 
 # === Blink utilities ===
 
@@ -24,17 +24,23 @@ mutable struct ConstructionViewer
   
   function ConstructionViewer()
     # create window and open developer console
-    win = Window()
-    opentools(win)
+    win = Window(Blink.Dict(:width => 620, :height => 620))
     
     # set stylesheet
     style!(win, """
-      /* needed to keep Ganja canvas from blowing up */
+      body {
+        background-color: #c8c0d0;
+      }
+      
+      /* maximum dimensions are needed to keep Ganja canvas from blowing up */
       canvas {
         min-width: 600px;
         max-width: 600px;
         min-height: 600px;
         max-height: 600px;
+        margin-top: 10px;
+        margin-left: 10px;
+        border-radius: 10px;
       }
     """)
     
@@ -50,8 +56,9 @@ mutable struct ConstructionViewer
       var elements = [];
       var palette = [];
       
-      // declare visualization handle
+      // declare handles for the visualization and its options
       var graph;
+      var graphOpt;
       
       // create scene function
       function scene() {
@@ -65,14 +72,13 @@ mutable struct ConstructionViewer
     
     # create view
     @js win begin
-      graph = CGA3.graph(
-        scene,
-        Dict(
-          "conformal" => true,
-          "gl" => true,
-          "grid" => true
-        )
+      graphOpt = Dict(
+        :conformal => true,
+        :gl => true,
+        :grid => true,
+        :devicePixelRatio => window.devicePixelRatio
       )
+      graph = CGA3.graph(scene, graphOpt)
       document.body.replaceChildren(graph)
     end
     
@@ -105,6 +111,16 @@ function display!(viewer::ConstructionViewer, elements::Matrix)
   @js viewer.win requestAnimationFrame(graph.update.bind(graph, scene));
 end
 
+function opentools!(viewer::ConstructionViewer)
+  size(viewer.win, 1240, 620)
+  opentools(viewer.win)
+end
+
+function closetools!(viewer::ConstructionViewer)
+  closetools(viewer.win)
+  size(viewer.win, 620, 620)
+end
+
 end
 
 # ~~~ sandbox setup ~~~