Thank you for reaching out to us. I checked your site and the min-width property is applying on the image element (see screenshot)
Can you please let us know what you're trying to achieve by specifying the
min-width property so we can guide you? If you want to increase the image clickable area, you can try wrapping the image in an anchor tag e.g:
<a href="#"><img id="homepage" src="http://aosmith.waterproducts.wpengine.com/wp-content/uploads/sites/2/2019/02/HotwaterComBackgroundEdited.png" usemap="#image-map" width="1920" height="286"></a>
Replace the '#' with the actual link in the above code. Hope this helps!