Is it possible to put an invisible line on a website so that the mouse can't go past a certain point?
You can't restrict the movement of the mouse, but you can hide the cursor using javascript, if you want to annoy everybody who visits your site. It will only work if people have javascript turned on, and it will annoy people. Don't do it.
You can't restrict the movement of the mouse, but you can hide the cursor using javascript, if you want to annoy everybody who visits your site. It will only work if people have javascript turned on, and it will annoy people. Don't do it.