Hi Christopher,
Running a Django development site on a 'real' web server like nginx is a bit non-standard, so there are a few hoops to jump through if you're going that route instead of ./manage.py runserver.
Normally, runserver would add in some extra logic to serve your static files from a consistent URL (specified by STATIC_URL, usually '/static/') even though the files themselves are located in various app-specific locations. To include this logic when you're not using runserver, add in one of the code snippets detailed here:
https://docs.djangoproject.com/en/1.7/ref/contrib/staticfiles/#static-file-development-view
However, be aware that this isn't suitable for production use. In production, you would run './manage.py collectstatic' to copy all of the static files to the location specified by STATIC_ROOT (usually 'static/' at the top-level of your project) - essentially what you're doing manually at the moment - and set up nginx to serve the '/static' URL from there.
(For Wagtail's own apps, there's an extra step in the chain: we use Django Compressor <
http://django-compressor.readthedocs.org> to compile SASS to CSS, and - when DEBUG is False only - compress the CSS/JS into a single file. You probably don't need to worry about that detail right now - it just means that Wagtail's CSS ends up in the 'CACHE' directory under STATIC_ROOT, where it should be picked up by one of the mechanisms above.)
- Matt