Eosc rtc (#212)

* Adding RTC extension

* Adding border-top CSS style

---------

Co-authored-by: gonimoro <>

single-user-eosc/Dockerfile

@@ -24,7 +24,10 @@ RUN mamba install -y --quiet \
 	plotly \
 	graphviz \
 	jq \
-	nb_conda_kernels \
+	nb_conda_kernels \ 
+        # RTC extension, must be disabled
+        # before Lab starts to work without RTC 
+        jupyter-collaboration=2.1.2 \
         # resource usage info in GUI
         jupyter-resource-usage \
     && conda clean --all

single-user-eosc/eosc/custom.css

@@ -451,4 +451,11 @@ all of MD as it is not optimized for dense, information rich UIs.
   .lm-MenuBar-item {
     line-height: 20px !important;
   }
-
+
+/* Modified extracted style from JupyterLab menus.css
+https://github.com/jupyterlab/jupyterlab/blob/0546815cb2615a7460c59dbf0494ddc94a04e139/packages/application/style/menus.css
+to allow border-top appear in default view because otherwise it is present only in single-doc view. 
+*/
+.lm-MenuBar.lm-mod-active .lm-MenuBar-item.lm-mod-active {
+  border-top: var(--jp-border-width) solid var(--jp-border-color1) !important;
+}