Removed border on default CSS preview to make it prettier
Removed border on default CSS preview to make it prettier

timmyomahony/django-pagedown,ministryofjustice/django-pagedown,ministryofjustice/django-pagedown,kaushalaman/django-pagedown,kaushalaman/django-pagedown,kaushalaman/django-pagedown,ministryofjustice/django-pagedown,timmyomahony/django-pagedown,timmyomahony/django-pagedown