Chat app CSS illustration [SASS/BEM]

hey man with the background you need them to surpass the edge of the viewport so you should try giving them a position: fixed; then for the purple one try left: -200px; top: 0; then just style the height to however long you want it, this will push it off the page slighty and it should look better, as for the right grey background peice you would want to swap it so bottom: 0 right: 200px; etc.. hope this helps!