Add CSS to guide/index and placeholder-lesson
Add CSS test for 'warning'
Add debug page for unfinished lessons
Add support for lightweight <mark>up
Add support for lesson titles
Add lesson: adjectives
Add lesson: nouns
Show finished lessons on debug.guide
Refactor nav bar to its own file
Rename 'layout.html' as 'base.html'
Refactor navbar CSS
Clean up index page
Fix title bug in CSS debug page
Add lesson: present-tense-verbs

It's still missing the verb table, though.
Expand CSS debug coverage
Fix API bugs in /dicts/mw
Create 'div.narrow' selector and use it liberally