Mobile Display Issues

[amandahope10]

I have been trying for days to get my website banner to resize correctly for mobile viewers. It fits the screen perfectly when viewing from a desktop, but only 1/4 of the banner, if that, shows when viewing on a mobile device.  I have searched and discovered that several other people have had this same issue.  I tried resizing the banner to a size mentioned in a previous thread and that DID NOT work.  Please tell me someone can actually walk me through getting this fixed.

http://theolivecartboutique.square.site/