Navigating through the different card levels was very important to us. We did not want users to have to back out to explore another topic and we also wanted the user to have an understanding where they were at all times. The navigation we came up with shows which of the six cards they are currently exploring, and provides additional feedback by blinking when the user changes cards. In addition the bar changes colors based on the colors assigned to each topic and it is accessible using mobile gestures and keyboard commands.