in django, you need to set up things a little bit, so that django (in local machine) or your web server (if you deploy the code to production) will find and render the static files (they are: css, images and js files) correctly.
here you read how you set it up first in django itself.
at the end, you will have something like this in your html file:
{% load staticfiles %}
<link href="{% static 'css/templatemo_style.css' %}" rel="stylesheet" type="text/css" />
so, your static files dont live directly in the same folder where html files live, but in their own folders, I normally call them site-static.
and here how you set up PyCharm with Django by the way :) http://www.django-tips.com/tip/how-to-setup-pycharm-for-django/31/
cssandhtmlfile should be at same directorycss/file.cssor../file.css.... read more about rules