LIL-428. Fix button styles in course lessons template

apps/course/templates/course/course_only_lessons.html

@@ -134,18 +134,18 @@
         </div>
       </div>
       <div class="course__actions">
-          <a href="{% url 'course' course.id %}" class="course__action btn btn_lg btn_stroke">Описание курса</a>
+          <a href="{% url 'course' course.id %}" class="course__action btn btn_lg{% if not only_lessons %} btn_stroke{% else %} btn_gray{% endif %}">Описание курса</a>
           {% if request.user.role == request.user.AUTHOR_ROLE or request.user.role == request.user.ADMIN_ROLE %}
           <a
             href="{% url 'course-only-lessons' course.id %}"
-            class="course__action btn btn_lg btn_gray"
+            class="course__action btn btn_lg{% if not only_lessons %} btn_stroke{% else %} btn_gray{% endif %}"
             {% if not user.is_authenticated %}data-popup=".js-popup-auth"{% endif %}
             >УРОКИ
           </a>
           {% else %}
           <a
             href="{% if paid %}{% url 'course-only-lessons' course.id %}{% else %}#{% endif %}"
-            class="course__action btn btn_lg btn_gray"
+            class="course__action btn btn_lg{% if not only_lessons %} btn_stroke{% else %} btn_gray{% endif %}"
             >УРОКИ
             {% if not paid %}
             <svg class="icon icon-lock">