diff --git a/Ooui.AspNetCore/WebSocketHandler.cs b/Ooui.AspNetCore/WebSocketHandler.cs
index 0c22f74..ce6f417 100644
--- a/Ooui.AspNetCore/WebSocketHandler.cs
+++ b/Ooui.AspNetCore/WebSocketHandler.cs
@@ -32,19 +32,30 @@ namespace Ooui.AspNetCore
             return id;
         }
 
+
+
         public static async Task HandleWebSocketRequestAsync (HttpContext context)
         {
+            void BadRequest (string message)
+            {
+                context.Response.StatusCode = StatusCodes.Status400BadRequest;
+                context.Response.ContentType = "text/plain; charset=utf-8";
+                using (var sw = new System.IO.StreamWriter (context.Response.Body)) {
+                    sw.WriteLine (message);
+                }
+            }
+
             //
             // Make sure we get a good ID
             //
             if (!context.Request.Query.TryGetValue ("id", out var idValues)) {
-                context.Response.StatusCode = StatusCodes.Status400BadRequest;
+                BadRequest ("Missing `id`");
                 return;
             }
 
-            var id = idValues.FirstOrDefault ();
+            var id = idValues.LastOrDefault ();
             if (id == null || id.Length != 32) {
-                context.Response.StatusCode = StatusCodes.Status400BadRequest;
+                BadRequest ("Invalid `id`");
                 return;
             }
 
@@ -52,7 +63,7 @@ namespace Ooui.AspNetCore
             // Find the pending session
             //
             if (!pendingSessions.TryRemove (id, out var pendingSession)) {
-                context.Response.StatusCode = StatusCodes.Status400BadRequest;
+                BadRequest ("Unknown `id`");
                 return;
             }
 
@@ -60,16 +71,32 @@ namespace Ooui.AspNetCore
             // Reject the session if it's old
             //
             if ((DateTime.UtcNow - pendingSession.RequestTimeUtc) > SessionTimeout) {
-                context.Response.StatusCode = StatusCodes.Status400BadRequest;
+                BadRequest ("Old `id`");
                 return;
             }
 
+            //
+            // Set the element's dimensions
+            //
+            if (!context.Request.Query.TryGetValue ("w", out var wValues) || wValues.Count < 1) {
+                BadRequest ("Missing `w`");
+                return;
+            }
+            if (!context.Request.Query.TryGetValue ("h", out var hValues) || hValues.Count < 1) {
+                BadRequest ("Missing `h`");
+                return;
+            }
+            if (!double.TryParse (wValues.Last (), out var w))
+                w = 640;
+            if (!double.TryParse (hValues.Last (), out var h))
+                h = 480;
+
             //
             // OK, Run
             //
             var token = CancellationToken.None;
             var webSocket = await context.WebSockets.AcceptWebSocketAsync ("ooui");
-            var session = new Ooui.UI.Session (webSocket, pendingSession.Element, token);
+            var session = new Ooui.UI.Session (webSocket, pendingSession.Element, w, h, token);
             await session.RunAsync ().ConfigureAwait (false);
         }
 
diff --git a/Ooui.Forms/Extensions/ElementExtensions.cs b/Ooui.Forms/Extensions/ElementExtensions.cs
index eb64812..50b7cb6 100644
--- a/Ooui.Forms/Extensions/ElementExtensions.cs
+++ b/Ooui.Forms/Extensions/ElementExtensions.cs
@@ -8,15 +8,35 @@ namespace Ooui.Forms.Extensions
         public static SizeRequest GetSizeRequest (this Ooui.Element self, double widthConstraint, double heightConstraint,
             double minimumWidth = -1, double minimumHeight = -1)
         {
-            var s = self.Text.MeasureSize (self.Style);
+            var rw = 0.0;
+            var rh = 0.0;
+            Size s = new Size (0, 0);
+            var measured = false;
 
-            var request = new Size (
-                double.IsPositiveInfinity (s.Width) ? double.PositiveInfinity : s.Width,
-                double.IsPositiveInfinity (s.Height) ? double.PositiveInfinity : s.Height);
-            var minimum = new Size (minimumWidth < 0 ? request.Width : minimumWidth,
-                minimumHeight < 0 ? request.Height : minimumHeight);
+            if (self.Style.Width.Equals ("inherit")) {
+                s = self.Text.MeasureSize (self.Style);
+                measured = true;
+                rw = double.IsPositiveInfinity (s.Width) ? double.PositiveInfinity : s.Width;
+            }
+            else {
+                rw = self.Style.GetNumberWithUnits ("width", "px", 640);
+            }
 
-            return new SizeRequest (request, minimum);
+            if (self.Style.Height.Equals ("inherit")) {
+                if (!measured) {
+                    s = self.Text.MeasureSize (self.Style);
+                    measured = true;
+                }
+                rh = double.IsPositiveInfinity (s.Height) ? double.PositiveInfinity : s.Height;
+            }
+            else {
+                rh = self.Style.GetNumberWithUnits ("height", "px", 480);
+            }
+
+            var minimum = new Size (minimumWidth < 0 ? rw : minimumWidth,
+                minimumHeight < 0 ? rh : minimumHeight);
+
+            return new SizeRequest (new Size (rw, rh), minimum);
         }
     }
 }
diff --git a/Ooui.Forms/Platform.cs b/Ooui.Forms/Platform.cs
index 5295ac6..938adb2 100644
--- a/Ooui.Forms/Platform.cs
+++ b/Ooui.Forms/Platform.cs
@@ -33,16 +33,17 @@ namespace Ooui.Forms
         {
             _renderer = new PlatformRenderer (this);
 
-            MessagingCenter.Subscribe(this, Page.AlertSignalName, (Page sender, AlertArguments arguments) =>
-            {
-                var alert = new DisplayAlert(arguments);
+            _renderer.Style.PropertyChanged += HandleRendererStyle_PropertyChanged;
+
+            MessagingCenter.Subscribe (this, Page.AlertSignalName, (Page sender, AlertArguments arguments) => {
+                var alert = new DisplayAlert (arguments);
                 alert.Clicked += CloseAlert;
 
-                _renderer.AppendChild(alert.Element);
+                _renderer.AppendChild (alert.Element);
 
-                void CloseAlert(object s, EventArgs e)
+                void CloseAlert (object s, EventArgs e)
                 {
-                    _renderer.RemoveChild(alert.Element);
+                    _renderer.RemoveChild (alert.Element);
                 }
             });
         }
@@ -128,6 +129,12 @@ namespace Ooui.Forms
                 Console.Error.WriteLine ("Potential view double add");
         }
 
+        void HandleRendererStyle_PropertyChanged (object sender, System.ComponentModel.PropertyChangedEventArgs e)
+        {
+            var pageRenderer = GetRenderer (Page);
+            pageRenderer?.SetElementSize (Ooui.Forms.Extensions.ElementExtensions.GetSizeRequest (_renderer, double.PositiveInfinity, double.PositiveInfinity).Request);
+        }
+
         void INavigation.InsertPageBefore (Page page, Page before)
         {
             throw new NotImplementedException ();
diff --git a/Ooui.Forms/PlatformRenderer.cs b/Ooui.Forms/PlatformRenderer.cs
index 6e8d939..d555803 100644
--- a/Ooui.Forms/PlatformRenderer.cs
+++ b/Ooui.Forms/PlatformRenderer.cs
@@ -9,6 +9,8 @@ namespace Ooui.Forms
 
 		public Platform Platform => platform;
 
+        public override bool WantsFullScreen => true;
+
 		public PlatformRenderer (Platform platform)
 		{
 			this.platform = platform;
diff --git a/Ooui.Forms/VisualElementTracker.cs b/Ooui.Forms/VisualElementTracker.cs
index 6efb363..1e570ee 100644
--- a/Ooui.Forms/VisualElementTracker.cs
+++ b/Ooui.Forms/VisualElementTracker.cs
@@ -142,10 +142,10 @@ namespace Ooui.Forms
             bool shouldUpdate = width > 0 && height > 0 && parent != null && (boundsChanged || parentBoundsChanged);
             if (shouldUpdate) {
                 uiview.Style.Position = "absolute";
-                uiview.Style.Left = x + "px";
-                uiview.Style.Top = y + "px";
-                uiview.Style.Width = width + "px";
-                uiview.Style.Height = height + "px";
+                uiview.Style.Left = x;
+                uiview.Style.Top = y;
+                uiview.Style.Width = width;
+                uiview.Style.Height = height;
                 Renderer.SetControlSize (new Size (width, height));
             }
             else if (width <= 0 || height <= 0) {
diff --git a/Ooui/Client.js b/Ooui/Client.js
index 779ca36..108fc35 100644
--- a/Ooui/Client.js
+++ b/Ooui/Client.js
@@ -18,6 +18,7 @@ const mouseEvents = {
     wheel: true,
 };
 
+// Try to close the socket gracefully
 window.onbeforeunload = function() {
     if (socket != null) {
         socket.close (1001, "Unloading page");
@@ -27,10 +28,22 @@ window.onbeforeunload = function() {
     return null;
 }
 
+function getSize () {
+    return {
+        height: window.innerHeight,
+        width: window.innerWidth
+    };
+}
+
+// Main entrypoint
 function ooui (rootElementPath) {
     var opened = false;
 
-    socket = new WebSocket ("ws://" + document.location.host + rootElementPath, "ooui");
+    var initialSize = getSize ();
+    var wsArgs = (rootElementPath.indexOf("?") >= 0 ? "&" : "?") +
+        "w=" + initialSize.width + "&h=" + initialSize.height;
+
+    socket = new WebSocket ("ws://" + document.location.host + rootElementPath + wsArgs, "ooui");
 
     socket.addEventListener ("open", function (event) {
         console.log ("Web socket opened");
@@ -61,6 +74,34 @@ function ooui (rootElementPath) {
     });
 
     console.log("Web socket created");
+
+    // Throttled window resize event
+    (function() {
+        window.addEventListener("resize", resizeThrottler, false);
+
+        var resizeTimeout;
+        function resizeThrottler() {
+            if (!resizeTimeout) {
+                resizeTimeout = setTimeout(function() {
+                    resizeTimeout = null;
+                    actualResizeHandler();            
+                }, 100);
+            }
+        }
+
+        function resizeHandler() {
+            const em = {
+                m: "event",
+                id: 42,
+                k: "window.resize",
+                v: getSize (),
+            };
+            const ems = JSON.stringify (em);
+            if (socket != null)
+                socket.send (ems);
+            if (debug) console.log ("Event", em);
+        }    
+    }());
 }
 
 function getNode (id) {
diff --git a/Ooui/Element.cs b/Ooui/Element.cs
index 253f57d..8ba85e9 100644
--- a/Ooui/Element.cs
+++ b/Ooui/Element.cs
@@ -90,6 +90,12 @@ namespace Ooui
             remove => RemoveEventListener ("wheel", value);
         }
 
+        /// <summary>
+        /// A signal to Ooui that this element should take up the
+        /// entire browser window.
+        /// </summary>
+        public virtual bool WantsFullScreen => false;
+
         protected Element (string tagName)
             : base (tagName)
         {
diff --git a/Ooui/Style.cs b/Ooui/Style.cs
index 1a0fedb..cec8577 100644
--- a/Ooui/Style.cs
+++ b/Ooui/Style.cs
@@ -11,6 +11,10 @@ namespace Ooui
 
         readonly Dictionary<string, Value> properties =
             new Dictionary<string, Value> ();
+        static readonly private char[] numberChars = new char[] {
+            '0','1','2','3','4','5','6','7','8','9',
+            '.','-','+',
+        };
 
         public Value AlignSelf {
             get => this["align-self"];
@@ -126,7 +130,7 @@ namespace Ooui
 
         public Value Bottom {
             get => this["bottom"];
-            set => this["bottom"] = value;
+            set => this["bottom"] = AddNumberUnits (value, "px");
         }
 
         public Value Clear {
@@ -196,12 +200,12 @@ namespace Ooui
 
         public Value Height {
             get => this["height"];
-            set => this["height"] = value;
+            set => this["height"] = AddNumberUnits (value, "px");
         }
 
         public Value Left {
             get => this["left"];
-            set => this["left"] = value;
+            set => this["left"] = AddNumberUnits (value, "px");
         }
 
         public Value LineHeight {
@@ -301,7 +305,7 @@ namespace Ooui
 
         public Value Top {
             get => this["top"];
-            set => this["top"] = value;
+            set => this["top"] = AddNumberUnits (value, "px");
         }
 
         public Value Transform {
@@ -326,7 +330,7 @@ namespace Ooui
 
         public Value Width {
             get => this["width"];
-            set => this["width"] = value;
+            set => this["width"] = AddNumberUnits (value, "px");
         }
 
         public Value ZIndex {
@@ -396,5 +400,34 @@ namespace Ooui
             }
             return o.ToString ();
         }
+
+        static string AddNumberUnits (object val, string units)
+        {
+            if (val is string s)
+                return s;
+            if (val is IConvertible c)
+                return c.ToString (System.Globalization.CultureInfo.InvariantCulture) + units;
+            return val.ToString ();
+        }
+
+        public double GetNumberWithUnits (string key, string units, double baseValue)
+        {
+            var v = this[key];
+            if (v == null)
+                return 0;
+
+            if (v is string s) {
+                var lastIndex = s.LastIndexOfAny (numberChars);
+                if (lastIndex < 0)
+                    return 0;
+                var num = double.Parse (s.Substring (0, lastIndex + 1), System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture);
+                return num;
+            }
+
+            if (v is IConvertible c)
+                return c.ToDouble (System.Globalization.CultureInfo.InvariantCulture);
+
+            return 0;
+        }
     }
 }
diff --git a/Ooui/UI.cs b/Ooui/UI.cs
index 079972b..b3a3ac9 100644
--- a/Ooui/UI.cs
+++ b/Ooui/UI.cs
@@ -436,7 +436,7 @@ namespace Ooui
             // Create a new session and let it handle everything from here
             //
             try {
-                var session = new Session (webSocket, element, serverToken);
+                var session = new Session (webSocket, element, 1024, 768, serverToken);
                 await session.RunAsync ().ConfigureAwait (false);
             }
             catch (WebSocketException ex) when (ex.WebSocketErrorCode == WebSocketError.ConnectionClosedPrematurely) {
@@ -473,11 +473,15 @@ namespace Ooui
             readonly System.Timers.Timer sendThrottle;
             DateTime lastTransmitTime = DateTime.MinValue;
             readonly TimeSpan throttleInterval = TimeSpan.FromSeconds (1.0 / 30); // 30 FPS max
+            readonly double initialWidth;
+            readonly double initialHeight;
 
-            public Session (WebSocket webSocket, Element element, CancellationToken serverToken)
+            public Session (WebSocket webSocket, Element element, double initialWidth, double initialHeight, CancellationToken serverToken)
             {
                 this.webSocket = webSocket;
                 this.element = element;
+                this.initialWidth = initialWidth;
+                this.initialHeight = initialHeight;
 
                 //
                 // Create a new session cancellation token that will trigger
@@ -525,6 +529,10 @@ namespace Ooui
                     //
                     // Add it to the document body
                     //
+                    if (element.WantsFullScreen) {
+                        element.Style.Width = initialWidth;
+                        element.Style.Height = initialHeight;
+                    }
                     QueueMessage (Message.Call ("document.body", "appendChild", element));
 
                     //