add width:100% to vbox for webkit / FF consistency

closes  #3049

IPython/frontend/html/notebook/static/less/flexible-box-model.less

@@ -1,97 +1,99 b''
 
 /* Flexible box model classes */
 /* Taken from Alex Russell http://infrequently.org/2009/08/css-3-progress/ */
 
 .hbox {
 	display: -webkit-box;
 	-webkit-box-orient: horizontal;
 	-webkit-box-align: stretch;
 
 	display: -moz-box;
 	-moz-box-orient: horizontal;
 	-moz-box-align: stretch;
 
 	display: box;
 	box-orient: horizontal;
 	box-align: stretch;
 }
 
 .hbox > * {
 	-webkit-box-flex: 0;
 	-moz-box-flex: 0;
 	box-flex: 0;
 }
 
 .vbox {
 	display: -webkit-box;
 	-webkit-box-orient: vertical;
 	-webkit-box-align: stretch;
 
 	display: -moz-box;
 	-moz-box-orient: vertical;
 	-moz-box-align: stretch;
 
 	display: box;
 	box-orient: vertical;
 	box-align: stretch;
+	/* width must be 100% to force FF to behave like webkit */
+	width: 100%;
 }
 
 .vbox > * {
 	-webkit-box-flex: 0;
 	-moz-box-flex: 0;
 	box-flex: 0;
 }
 
 .reverse {
 	-webkit-box-direction: reverse;
 	-moz-box-direction: reverse;
 	box-direction: reverse;
 }
 
 .box-flex0 {
 	-webkit-box-flex: 0;
 	-moz-box-flex: 0;
 	box-flex: 0;
 }
 
 .box-flex1, .box-flex {
 	-webkit-box-flex: 1;
 	-moz-box-flex: 1;
 	box-flex: 1;
 }
 
 .box-flex2 {
 	-webkit-box-flex: 2;
 	-moz-box-flex: 2;
 	box-flex: 2;
 }
 
 .box-group1 {
 	-webkit-box-flex-group: 1;
 	-moz-box-flex-group: 1;
 	box-flex-group: 1;
 }
 
 .box-group2 {
 	-webkit-box-flex-group: 2;
 	-moz-box-flex-group: 2;
 	box-flex-group: 2;
 }
 
 .start {
 	-webkit-box-pack: start;
 	-moz-box-pack: start;
 	box-pack: start;
 }
 
 .end {
 	-webkit-box-pack: end;
 	-moz-box-pack: end;
 	box-pack: end;
 }
 
 .center {
 	-webkit-box-pack: center;
 	-moz-box-pack: center;
 	box-pack: center;
 }