I have a main.css file where all my styles are and some of my html files are loading them, but not all of them. All my html files extends base.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Document</title>
    <link href="static/css/main.css" rel="stylesheet" type="text/css" />
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script src="https://kit.fontawesome.com/2a770f4891.js" crossorigin="anonymous"></script>

    <title>{% block title %}E-Learning{% endblock %}</title>
</head>
<body>

<input type="checkbox" id="check">
<nav class="nav">

        <label for="check">
            <i class="fas fa-bars" id="sidebar_btn"></i>
        </label>


        {% if user.is_authenticated %}
        {% if user.first_name != '' or user.last_name != '' %}
        <b class="top-menu" style="font-size:20px; margin-right:5px;"> Hello, {{user.first_name}} {{user.last_name}}</b>
        {% else %}
        <b class="top-menu" style="font-size:20px; margin-right:5px;">Hello, {{ user.username }}</b>
        {% endif %}
        {% else %}
        {% endif %}
            {% if user.is_authenticated %}
        <a href="{% url 'logout' %}" class="top-menu">Log out</a>
        {% else %}
        <a href="{% url 'login' %}" class="top-menu"> Log In </a>
        <a href="{% url 'register' %}" class="top-menu">Register </a>
        {% endif %}
    </nav>

    <div class="sidebar">
        <a href="{% url 'subject_new' %}" > <span> Add </span></a>
    </div>

    <main class="content">

        {% block content %}
        {% endblock content %}
    </main>

</body>
</html>

and for example my register.html extends base.html (with all css files) just fine

{% extends 'base.html' %}

{% block content %}

{% if user.is_authenticated %}

<b>You're already logged in.</b>

{% else %}

  <form method="post">
    {% csrf_token %}
     <div class="register-window">
    {% for field in form %}
       <p class="label_tag"> {{ field.label_tag }} </p>
       {{ field }}
        {% if field.help_text %}
          <br> <small class="help_text">{{ field.help_text }}</small>
        {% endif %}
        {% for error in field.errors %}
          <p style="color: red">{{ error }}</p>
        {% endfor %}
    {% endfor %}
    <button type="submit" class="login-button">Register</button>
     </div>
  </form>

{% endif %}

{% endblock %}

but my subject_detail.html seems to ignore my css file

{% extends 'base.html' %}



    {% block content %}
<head>

    <link rel="stylesheet" href="static/css/main.css" />
</head>
<body>
<div class="subjecttitle">{{subject.name}}</div>

<div class="subjectlessons"><p>{{subject.header|safe}}</p></div>
     {% endblock content %}
</body>

I am doing this in django, so this is my settings.py

"""
Django settings for teamproject project.

Generated by 'django-admin startproject' using Django 3.1.3.

For more information on this file, see
https://docs.djangoproject.com/en/3.1/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.1/ref/settings/
"""
import os
from pathlib import Path

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.1/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'ewmxjw-q3eh=0-+9iq4*$8myvreo8-zg4v+*tkgz5q=+iqg%)q'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

# ALLOWED_HOSTS = []
ALLOWED_HOSTS = ['127.0.0.1', '.pythonanywhere.com']


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'eLearning',
    'ckeditor',
    'ckeditor_uploader',
    'crispy_forms',
    'django_cleanup',
]

CRISPY_TEMPLATE_PACK = 'bootstrap4'

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'teamproject.urls'

TEMPLATE_PATH = os.path.join(BASE_DIR, 'eLearning/Templates')

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [TEMPLATE_PATH],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'teamproject.wsgi.application'


# Database
# https://docs.djangoproject.com/en/3.1/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': str(os.path.join(BASE_DIR, "db.sqlite3")),
    }
}


# Password validation
# https://docs.djangoproject.com/en/3.1/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/3.1/topics/i18n/

# LANGUAGE_CODE = 'en-us'
LANGUAGE_CODE = 'pl-pl'

# TIME_ZONE = 'UTC'
TIME_ZONE = 'Europe/Warsaw'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.1/howto/static-files/

STATIC_URL = '/static/'
STATIC_ROOT = os.path.join(BASE_DIR, 'static')

MEDIA_URL = '/media/'
MEDIA_ROOT = 'media/'

CKEDITOR_UPLOAD_PATH = "uploads/"

LOGIN_URL = '/login'
AUTH_USER_MODEL = 'eLearning.User'
LOGIN_REDIRECT_URL = 'home'

# gmail-mail settings
EMAIL_HOST = "smtp.gmail.com"
EMAIL_HOST_USER = "elearningteamproject@gmail.com"
EMAIL_HOST_PASSWORD = 'projektzespolowy1'
EMAIL_PORT = 587
EMAIL_USE_TLS = True

CKEDITOR_CONFIGS = {
    'default': {
        "removePlugins": "resize, elementspath",
        'toolbar': 'Custom',
        'height': 300,
        'width': 600,        
        'toolbar_Custom': [
            ['Font', 'FontSize', 'Bold', 'Italic', 'Underline', 'Strike', 'Subscript', 'Superscript', 'TextColor', 'BGColor', 'RemoveFormat', 'Blockquote', 'Smiley', 'SpecialChar'],
            ['Cut', 'Copy', 'Paste', 'SelectAll', 'Find', 'List', 'Preview', 'NumberedList', 'BulletedList', 'JustifyLeft', 'JustifyCenter', 'JustifyRight', 'JustifyBlock', 'HorizontalRule'],
            [],
            ]
    }         
}

Every file extends base.html (I can tell by the header) but some of them ignore CSS file. If you need more files to try to solve my problem please ask and I will add this to question. Things I tried: I tried adding {% load static%}, python manage.py collectstatic, adding + static(settings.STATIC_URL, document_root=settings.STATIC_ROOT) at the end of my urls.py