Fix pop out window layout when resized to small height

T59

popup.html

@@ -72,6 +72,7 @@
 		bottom: 4em;
 		border: 0;
 		border-bottom: 1px solid #dfdfdf;
+		min-height: 0;
 	}
 	body.popout a#popout {
 		display: none;