diff --git a/Makefile b/Makefile
index 3302df2..67ea6c6 100644
--- a/Makefile
+++ b/Makefile
@@ -58,6 +58,7 @@ endif
 
 # --- EMSCRIPTEN-SPECIFIC ---
 ifeq ($(PLATFORM), emscripten)
+    PLATFORM_CFLAGS += -s USE_SDL=2
     LDFLAGS += -s USE_SDL=2\
 			   -s ASYNCIFY \
 			   -s ALLOW_MEMORY_GROWTH=1 \
diff --git a/src/arch/emscripten/devices.c b/src/arch/emscripten/devices.c
index 4d667b1..56d2754 100644
--- a/src/arch/emscripten/devices.c
+++ b/src/arch/emscripten/devices.c
@@ -60,32 +60,7 @@ i32 screen_open(void *data, u32 mode, u32 handle, u8 *buffer, u32 size) {
   memcpy(&info[8], &screen->height, sizeof(u32));
   memcpy(&info[12], &screen->buffer_size, sizeof(u32));
   screen->screen_buffer = (u8*)(buffer + 16);
-
-  screen->window =
-      SDL_CreateWindow("Reality Engine VM", SDL_WINDOWPOS_CENTERED,
-                       SDL_WINDOWPOS_CENTERED, screen->width, screen->height,
-                       SDL_WINDOW_SHOWN | SDL_WINDOW_ALLOW_HIGHDPI);
-
-  if (!screen->window) {
-    return -1;
-  }
-
-  screen->renderer =
-      SDL_CreateRenderer(screen->window, -1, SDL_RENDERER_ACCELERATED);
-  if (!screen->renderer) {
-    return -1;
-  }
-
-  screen->texture = SDL_CreateTexture(screen->renderer, SDL_PIXELFORMAT_RGB332,
-                                      SDL_TEXTUREACCESS_STREAMING,
-                                      screen->width, screen->height);
-
-  if (!screen->texture) {
-    fprintf(stderr, "SDL_CreateTexture failed: %s\n", SDL_GetError());
-    return -1;
-  }
-
-  SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "0");
+  
   return 0;
 }
 
diff --git a/src/arch/emscripten/main.c b/src/arch/emscripten/main.c
index e22622c..4c43664 100644
--- a/src/arch/emscripten/main.c
+++ b/src/arch/emscripten/main.c
@@ -33,59 +33,106 @@ static ScreenDeviceData screen_data = {0};
 static MouseDeviceData mouse_data = {0};
 static ConsoleDeviceData console_data = {0};
 
+static bool display_size_changed = false;
+
+// The callback:
+static EM_BOOL on_web_display_size_changed( int event_type, 
+  const EmscriptenUiEvent *event, void *user_data )
+{
+  display_size_changed = 1;  // custom global flag
+  return 0;
+}
+
+void scale_mouse_pos(u32 mouse_x, u32 mouse_y, u32 *vm_x, u32 *vm_y) {
+  int win_w, win_h;
+  SDL_GetWindowSize(screen_data.window, &win_w, &win_h);
+
+  f32 scale_x = (f32)win_w / screen_data.width;
+  f32 scale_y = (f32)win_h / screen_data.height;
+  f32 scale = SDL_min(scale_x, scale_y);
+
+  u32 dst_w = (u32)(screen_data.width * scale);
+  u32 dst_h = (u32)(screen_data.height * scale);
+  u32 dst_x = (win_w - dst_w) / 2;
+  u32 dst_y = (win_h - dst_h) / 2;
+
+  f32 rel_x = (f32)(mouse_x - dst_x);
+  f32 rel_y = (f32)(mouse_y - dst_y);
+
+  *vm_x = (u32)((rel_x / (f32)dst_w) * screen_data.width);
+  *vm_y = (u32)((rel_y / (f32)dst_h) * screen_data.height);
+
+  if (*vm_x >= screen_data.width) *vm_x = screen_data.width - 1;
+  if (*vm_y >= screen_data.height) *vm_y = screen_data.height - 1;
+}
+
 void mainloop() {
   SDL_Event event;
   SDL_PumpEvents();
-  while (SDL_PollEvent(&event)) {
-    switch (event.type) {
-    // Mouse events
-    case SDL_MOUSEMOTION:
-      mouse_data.x = event.motion.x;
-      mouse_data.y = event.motion.y;
-      break;
-
-    case SDL_MOUSEBUTTONDOWN:
-      if (event.button.button == SDL_BUTTON_LEFT)
-        mouse_data.btn1 = 1;
-      if (event.button.button == SDL_BUTTON_RIGHT)
-        mouse_data.btn2 = 1;
-      if (event.button.button == SDL_BUTTON_MIDDLE)
-        mouse_data.btn3 = 1;
-      if (event.button.button == SDL_BUTTON_X1)
-        mouse_data.btn4 = 1;
-      break;
-
-    case SDL_MOUSEBUTTONUP:
-      if (event.button.button == SDL_BUTTON_LEFT)
-        mouse_data.btn1 = 0;
-      if (event.button.button == SDL_BUTTON_RIGHT)
-        mouse_data.btn2 = 0;
-      if (event.button.button == SDL_BUTTON_MIDDLE)
-        mouse_data.btn3 = 0;
-      if (event.button.button == SDL_BUTTON_X1)
-        mouse_data.btn4 = 0;
-      break;
-
-    case SDL_FINGERMOTION:
-    case SDL_FINGERDOWN:
-    case SDL_FINGERUP: {
-
-      float x = event.tfinger.x * 640;
-      float y = event.tfinger.y * 480;
-
-      mouse_data.x = (int)x;
-      mouse_data.y = (int)y;
-
-      if (event.tfinger.fingerId == 0) {
-        if (event.type == SDL_FINGERDOWN || event.type == SDL_FINGERMOTION) {
-          mouse_data.btn1 = 1;
-        } else if (event.type == SDL_FINGERUP) {
-          mouse_data.btn1 = 0;
+    while (SDL_PollEvent(&event)) {
+      switch (event.type) {
+      case SDL_WINDOWEVENT:{
+        switch (event.window.event) {
+          case SDL_WINDOWEVENT_RESIZED:
+            screen_data.update = true;
+            break;
         }
+        break;        
+      }
+      case SDL_MOUSEMOTION: {
+        u32 vm_x, vm_y;
+        scale_mouse_pos(event.motion.x, event.motion.y, &vm_x, &vm_y);
+        mouse_data.x = vm_x;
+        mouse_data.y = vm_y;
+        break;
+      }
+      case SDL_MOUSEBUTTONDOWN:
+      case SDL_MOUSEBUTTONUP: {
+        u32 vm_x, vm_y;
+        scale_mouse_pos(event.button.x, event.button.y, &vm_x, &vm_y);
+        
+        mouse_data.x = vm_x; 
+        mouse_data.y = vm_y;
+
+        bool pressed = (event.type == SDL_MOUSEBUTTONDOWN);
+        if (event.button.button == SDL_BUTTON_LEFT) mouse_data.btn1 = pressed;
+        if (event.button.button == SDL_BUTTON_RIGHT) mouse_data.btn2 = pressed;
+        if (event.button.button == SDL_BUTTON_MIDDLE) mouse_data.btn3 = pressed;
+        if (event.button.button == SDL_BUTTON_X1) mouse_data.btn4 = pressed;
+        break;
+      }
+      case SDL_FINGERMOTION:
+      case SDL_FINGERDOWN:
+      case SDL_FINGERUP: {
+        int win_w, win_h;
+        SDL_GetWindowSize(screen_data.window, &win_w, &win_h);
+        
+        u32 touch_pixel_x = (u32)(event.tfinger.x * win_w);
+        u32 touch_pixel_y = (u32)(event.tfinger.y * win_h);
+
+        u32 vm_x, vm_y;
+        scale_mouse_pos(touch_pixel_x, touch_pixel_y, &vm_x, &vm_y);
+
+        mouse_data.x = vm_x;
+        mouse_data.y = vm_y;
+
+        if (event.tfinger.fingerId == 0) {
+           bool pressed = (event.type == SDL_FINGERDOWN || event.type == SDL_FINGERMOTION);
+           mouse_data.btn1 = pressed ? 1 : 0;
+        }
+        break;
+      }
       }
-      break;
-    }
     }
+
+  // In the emscripten_set_main_loop() callback:
+  if (display_size_changed)
+  {
+    double w, h;
+    emscripten_get_element_css_size( "#canvas", &w, &h );
+    SDL_SetWindowSize( screen_data.window, (int)w, (int) h );
+
+    display_size_changed = 0;
   }
 
   int cycles_this_frame = 0;
@@ -100,8 +147,26 @@ void mainloop() {
 
   if (screen_data.update) {
       if (screen_data.renderer && screen_data.texture) {
-          SDL_RenderCopy(screen_data.renderer, screen_data.texture, NULL, NULL);
-          SDL_RenderPresent(screen_data.renderer);
+        // Clear and render
+        SDL_RenderClear(screen_data.renderer);
+
+        int window_w, window_h;
+        SDL_GetWindowSize(screen_data.window, &window_w, &window_h);
+
+        // Calculate aspect ratio preserving scaling
+        f32 scale_x = (f32)window_w / screen_data.width;
+        f32 scale_y = (f32)window_h / screen_data.height;
+        f32 scale = SDL_min(scale_x, scale_y);
+
+        SDL_Rect dstrect = {
+            (i32)((window_w - screen_data.width * scale) / 2),
+            (i32)((window_h - screen_data.height * scale) / 2),
+            (i32)(screen_data.width * scale),
+            (i32)(screen_data.height * scale)};
+
+        SDL_RenderCopy(screen_data.renderer, screen_data.texture, NULL,
+                       &dstrect);
+        SDL_RenderPresent(screen_data.renderer);
       }
       screen_data.update = false;
   }
@@ -148,6 +213,7 @@ int main(int argc, char **argv) {
     return 1;
   }
   SDL_SetHint(SDL_HINT_TOUCH_MOUSE_EVENTS, "0");
+  SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "nearest");
 
 #ifdef __EMSCRIPTEN__
   emscripten_set_canvas_element_size("#canvas", 640, 480);
@@ -160,9 +226,24 @@ int main(int argc, char **argv) {
   screen_data.width = 640;
   screen_data.height = 480;
   screen_data.buffer_size = screen_data.width * screen_data.height;
-  screen_data.window = NULL;
-  screen_data.renderer = NULL;
-  screen_data.texture = NULL;
+  screen_data.window = SDL_CreateWindow("Reality Engine VM", SDL_WINDOWPOS_CENTERED,
+                       SDL_WINDOWPOS_CENTERED, 640, 480,
+                       SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN | SDL_WINDOW_ALLOW_HIGHDPI);
+
+  screen_data.renderer =
+      SDL_CreateRenderer(screen_data.window, -1, SDL_RENDERER_ACCELERATED);
+  if (!screen_data.renderer) {
+    return -1;
+  }
+
+  screen_data.texture = SDL_CreateTexture(screen_data.renderer, SDL_PIXELFORMAT_RGB332,
+                                      SDL_TEXTUREACCESS_STREAMING,
+                                      screen_data.width, screen_data.height);
+
+  if (!screen_data.texture) {
+    fprintf(stderr, "SDL_CreateTexture failed: %s\n", SDL_GetError());
+    return -1;
+  }
 
   mouse_data.x = 0;
   mouse_data.y = 0;
@@ -179,6 +260,11 @@ int main(int argc, char **argv) {
   vm_register_device(&vm, "/dev/term/0", "terminal", &console_data,
                      &console_device_ops, 4);
 
+  emscripten_set_resize_callback(
+    EMSCRIPTEN_EVENT_TARGET_WINDOW,
+    0, 0, on_web_display_size_changed
+  );
+
   emscripten_set_main_loop(mainloop, 0, 1);
   return 0;
 }
diff --git a/src/arch/emscripten/shell_minimal.html b/src/arch/emscripten/shell_minimal.html
index 8a8c6db..6e7fec8 100644
--- a/src/arch/emscripten/shell_minimal.html
+++ b/src/arch/emscripten/shell_minimal.html
@@ -208,8 +208,9 @@
       <input type="checkbox" id="resize">Resize canvas
       <input type="checkbox" id="pointerLock" checked>Lock/hide mouse pointer
       &nbsp;&nbsp;&nbsp;
-      <input type="button" value="Fullscreen" onclick="Module.requestFullscreen(document.getElementById('pointerLock').checked, 
+      <span><input type="button" value="Fullscreen" onclick="Module.canvas.requestFullscreen(document.getElementById('pointerLock').checked, 
                                                                                 document.getElementById('resize').checked)">
+      </span>
     </div>
     
     <hr/>