add centering and focus capabilities

lib/utils/size_extensions.dart

@@ -0,0 +1,18 @@
+import 'package:flutter/material.dart';
+
+extension SizeOps on Size {
+  Size operator /(double scalar) {
+    if (scalar == 0) {
+      throw ArgumentError('Division by zero is not allowed.');
+    }
+    return Size(width / scalar, height / scalar);
+  }
+
+  Size operator *(double scalar) {
+    return Size(width * scalar, height * scalar);
+  }
+
+  Offset toOffset() {
+    return Offset(width, height);
+  }
+}