Responsively changing layout to single-column + nav on smaller screens

app/assets/javascripts/components/containers/mastodon.jsx

app/assets/javascripts/components/features/compose/index.jsx

...s/javascripts/components/features/home_timeline/index.jsx

...vascripts/components/features/mentions_timeline/index.jsx

...javascripts/components/features/public_timeline/index.jsx

.../javascripts/components/features/ui/components/column.jsx

...cripts/components/features/ui/components/columns_area.jsx

.../javascripts/components/features/ui/components/drawer.jsx

...avascripts/components/features/ui/components/tabs_bar.jsx

app/assets/javascripts/components/features/ui/index.jsx

app/assets/stylesheets/components.scss

package.json

yarn.lock