Dark Mode Support

The site finally has dark mode. It follows your system theme by default, and if you'd rather pick one yourself there's a sun/moon button in the nav. Whatever you choose is saved in your browser, so it sticks around next time you visit.

What's new

• Dark mode on every page, from the generator to the documentation and everything in between.
• A theme toggle in the nav. Nothing fancy, it just flips the theme and remembers your choice.
• Toasts, popups, dropdowns and inputs switch along with the rest of the site.

Improvements

• The drop shadow under the nav when you scroll was basically invisible in dark mode, so it now gets a stronger shadow and a thin border there.
• Cleaned up a bunch of text colors that were slightly off from each other, so everything reads the same in both themes.