Dark Mode visual flash

[arekouzounian]

Dark mode is being handled by the footer component, which is the only client side component currently. Since it's a client side component, it gets to use the localStorage to check for dark mode, which lets the selection persist between refreshes.

Right now, whenever dark mode is selected, there is a visual flash on page load because the footer is loading last and setting the page theme to dark mode.

Maybe styles can be switched to have dark mode as default, but this would just result in the opposite error where the page would be dark before it updated.