         
         //update on layout
         syncHighlight()
+        
+        //update overlay view based on highlight position
+        overlayView.layer.borderColor = UIColor.orange.cgColor
+        overlayView.layer.borderWidth = 2
+        
+        switch self.traitCollection.horizontalSizeClass {
+        case .compact:
+            overlayView.frame = self.view.bounds
+        case .regular:
+            //check if highlight view is to left or right of screen
+            if highlightView.frame.midX > self.view.bounds.midX {
+                overlayView.frame = CGRect(x: 0, y: 0, width: highlightView.frame.minX, height: self.view.bounds.height)
+            } else {
+                overlayView.frame = CGRect(x: highlightView.frame.maxX, y: 0, width: self.view.bounds.width - highlightView.frame.maxX, height: self.view.bounds.height)
+            }
+        case.unspecified:
+            overlayView.frame = .zero
+        }
+        
     }
 }

    override func viewDidLoad() {
        super.viewDidLoad()
        
        //add highlight view
        self.view.addSubview(highlightView)
        
        //observe position

    
    let highlight: Highlight
    let highlightView: HighlightView
    let overlayView: UIView
    
    required init(highlight: Highlight) {
        self.highlightView = HighlightView()
        self.highlight = highlight
        self.overlayView = UIView()
        
        super.init(nibName: nil, bundle: nil)
    }
