When I start the project in desktop view the slider is positioned correctly inside the gray box, even when I then switch to a mobile view in Chrome’s developer tools. But when I reload the site in mobile view, element.screenCorners seems to return the wrong values and the slider is positioned wrongly.
This can also be reproduced on a real mobile device, where my slider was nowhere to be found.
Maybe I did something wrong, I’m not sure. The slider code is inside slider.js in scripts.
Image of wrong slider (blue line):