fill #site height with notebook containers
fill #site height with notebook containers

avoids cutoff of overlay elements

ipython/ipywidgets,SylvainCorlay/ipywidgets,jupyter-widgets/ipywidgets,ipython/ipywidgets,cornhundred/ipywidgets,cornhundred/ipywidgets,cornhundred/ipywidgets,jupyter-widgets/ipywidgets,jupyter-widgets/ipywidgets,cornhundred/ipywidgets,jupyter-widgets/ipywidgets,SylvainCorlay/ipywidgets,SylvainCorlay/ipywidgets,ipython/ipywidgets,ipython/ipywidgets,cornhundred/ipywidgets,ipython/ipywidgets,SylvainCorlay/ipywidgets