1) Split TFD main pages into 'has didactic content', 'has no didactic content', and 'is viz' sections. 2) Split TFD navbar dropdowns into the aforementioned sections. 3) Gave all subsection menu links icons based on the aforementioned sections (no effect on the mobile menu as the mobile menu has no sub-sections) 4) Fixed thought viz spacing 5) Fixed the continue button on the activity tracker since it still had the old style 6) Fixed a bug with detecting incomplete content in the navbar if the content is not marked as today's content. 7) Fixed the height of the alert messages so that they no longer stack and push other elements of the page [Finishes: #75384936] [Finishes: #75387166] [Finishes: #77216940] [Finishes: #77210222] [Finishes: #77210078]