Maps.com contacted me to help with CSS layout for their ongoing development of interactive historical maps for classrooms students.
The biggest challenge was getting the timeline and it's buttons (positioned in JavaScript) to keep their proportional spacing as the timeline collapsed and expanded in different viewports.
The designers on this project had a number of specific viewport sizes they were designing for, so I employed media queries to control the size of the timeline, collapsing of the left column key and the other JavaScript controls on the page.