I have a web map embedded into my organization's website through an iframe block. I used URL parameters to dock the legend/info panel to the left. It looks fine on a computer, but on a mobile device, the legend panel is so wide that it covers nearly the entire map and you can barely see the arrow to collapse it.
I thought about creating an instant app to embed instead of the map, but I'm not sure if I would be able to alter the panel dimensions there, either?
Another idea I had was to show a static image of the map with a note to click the map to view it full screen if viewed on a screen under certain dimensions -- is this possible with an embedded map or instant app?