How to put it responsive

Hi, i’m using this plugin and it works 🙂 On the computer screen it looks ok but I want to view the image on the mobile screen without it being cut to the right (The image does not scale correctly and does not fit the correct width)

I tried to change the original CSS putting ‘auto’ in width but doesn’t work

[compare before=”http://domain.com/imagename1.jpg” after=”http://domain.com/imagename2.jpg” width=”600px” height=”400px”]

[compare before=”http://domain.com/imagename1.jpg” after=”http://domain.com/imagename2.jpg” width=”auto” height=”400px”]

Is there any additional CSS code that can solve this? Thank you!