diff --git a/lib/cyberarm_engine/common.rb b/lib/cyberarm_engine/common.rb
index f11e997..133b82c 100644
--- a/lib/cyberarm_engine/common.rb
+++ b/lib/cyberarm_engine/common.rb
@@ -8,8 +8,11 @@ module CyberarmEngine
       window.current_state
     end
 
-    def previous_state
-      window.previous_state
+    def previous_state(state = nil)
+      raise "Only available for CyberarmEngine::GameState and subclasses" unless is_a?(CyberarmEngine::GameState) || state.is_a?(CyberarmEngine::GameState)
+
+      i = window.states.index(state || self)
+      window.states[i - 1] unless (i - 1).negative?
     end
 
     def pop_state
diff --git a/lib/cyberarm_engine/ui/element.rb b/lib/cyberarm_engine/ui/element.rb
index cddba7f..5fbf7ab 100644
--- a/lib/cyberarm_engine/ui/element.rb
+++ b/lib/cyberarm_engine/ui/element.rb
@@ -447,18 +447,10 @@ module CyberarmEngine
       end
 
       if @parent && @style.fill # Handle fill behavior
-        fill_siblings = @parent.children.select { |c| c.style.fill }.count.to_f # include self since we're dividing
-
         if dimension == :width && @parent.is_a?(Flow)
-          space_available_width = ((@parent.content_width - (@parent.children.reject { |c| c.style.fill }).map(&:outer_width).sum) / fill_siblings)
-          space_available_width = space_available_width.nan? ? 0 : space_available_width.floor # The parent element might not have its dimensions, yet.
-
           return space_available_width - noncontent_width
 
         elsif dimension == :height && @parent.is_a?(Stack)
-          space_available_height = ((@parent.content_height - (@parent.children.reject { |c| c.style.fill }).map(&:outer_height).sum) / fill_siblings)
-          space_available_height = space_available_height.nan? ? 0 : space_available_height.floor # The parent element might not have its dimensions, yet.
-
           return space_available_height - noncontent_height
         end
 
@@ -470,6 +462,22 @@ module CyberarmEngine
       new_size
     end
 
+    def space_available_width
+      # TODO: This may get expensive if there are a lot of children, probably should cache it somehow
+      fill_siblings = @parent.children.select { |c| c.style.fill }.count.to_f # include self since we're dividing
+
+      available_space = ((@parent.content_width - (@parent.children.reject { |c| c.style.fill }).map(&:outer_width).sum) / fill_siblings)
+      (available_space.nan? || available_space.infinite?) ? 0 : available_space.floor # The parent element might not have its dimensions, yet.
+    end
+
+    def space_available_height
+      # TODO: This may get expensive if there are a lot of children, probably should cache it somehow
+      fill_siblings = @parent.children.select { |c| c.style.fill }.count.to_f # include self since we're dividing
+
+      available_space = ((@parent.content_height - (@parent.children.reject { |c| c.style.fill }).map(&:outer_height).sum) / fill_siblings)
+      (available_space.nan? || available_space.infinite?) ? 0 : available_space.floor # The parent element might not have its dimensions, yet.
+    end
+
     def background=(_background)
       @style.background_canvas.background = _background
       update_background
diff --git a/lib/cyberarm_engine/ui/elements/container.rb b/lib/cyberarm_engine/ui/elements/container.rb
index 4f75e3d..6e4fd20 100644
--- a/lib/cyberarm_engine/ui/elements/container.rb
+++ b/lib/cyberarm_engine/ui/elements/container.rb
@@ -136,7 +136,31 @@ module CyberarmEngine
           @height = _height || (@children.map { |c| c.y + c.outer_height }.max || 0).floor
         end
 
-        # Move child to parent after positioning
+        # FIXME: Correctly handle alignment when element has siblings
+        # FIXME: Enable alignment for any element, not just containers
+        if @style.v_align
+          space = space_available_height
+
+          case @style.v_align
+          when :center
+            @y = parent.height / 2 - height / 2
+          when :bottom
+            @y = parent.height - height
+          end
+        end
+
+        if @style.h_align
+          space = space_available_width
+
+          case @style.h_align
+          when :center
+            @x = parent.width / 2 - width / 2
+          when :right
+            @x = parent.width - width
+          end
+        end
+
+        # Move children to parent after positioning
         @children.each do |child|
           child.x += (@x + @style.border_thickness_left) - style.margin_left
           child.y += (@y + @style.border_thickness_top) - style.margin_top
diff --git a/lib/cyberarm_engine/window.rb b/lib/cyberarm_engine/window.rb
index 763589a..c5c7de8 100644
--- a/lib/cyberarm_engine/window.rb
+++ b/lib/cyberarm_engine/window.rb
@@ -139,12 +139,6 @@ module CyberarmEngine
       @states.last
     end
 
-    def previous_state
-      if @states.size > 1 && (state = @states[@states.size - 2])
-        state
-      end
-    end
-
     def pop_state
       @states.pop
     end