I was having a hard time figuring out a way to create a responsibe Google Maps application template. Learn more about this template from my blog post.
View a working version of the application
In the PC view you will have a menu bar on top, a filter on the side, and the legend on the bottom of the page.
In the mobile view, you have the menu on the top with a button to expand the filter on the side and the legend will be shown by clicking the bottom button.