Getting the size of the hotbar and mouse

How would I get the current size of the mouse? I have a bar that appears underneath the mouse and since the mouse size varies across different resolutions, it doesn’t show up the same way on every resolution. I know how to get the position of the mouse and position the GUI based on it, but I’m not sure how to get the size of the mouse.

To add on, is there also a way to get the size and position of the hotbar (the bar of tools that appear if you have tools in your backpack)? Because certain GUI appear behind it on certain resolutions (usually mobile) and it’d be great if I could position it based on the size and position so it’s more visible.