static/pages/css/custom_ckeditor.css .django-ckeditor-widget, .cke_editor_id_content { width: 100% !important; max-width: 821px !important; } Inyectar en pages_menu.html <link href="{% static 'pages/css/custom_ckeditor.css' %}" rel="stylesheet"> Inyectar en admin.py from django.contrib import admin from .models import Page class PageAdmin(admin.ModelAdmin): list_display = ('title', 'order') # Inyectamos nuestro fichero css class Media: css = { 'all': ('pages/css/custom_ckeditor.css',) } admin.site.register(Page, PageAdmin)