Resolve "Improve week view for mobile devices (size s)"

Closes #186 (closed)

aleksis/apps/alsijil/static/css/alsijil/week_view.css

@@ -96,12 +96,9 @@ p.subtitle {
 
 .unfold-trigger i.material-icons {
     transition: transform .5s 0s ease-in-out;
-    rotate: 270deg;
-    rotation: 270deg;
-    -webkit-transform: rotate(270deg);
+    transform: rotate(-90deg);
 }
 
 .unfold-trigger.vertical i.material-icons {
-    transform: rotate(-90deg);
-    -webkit-transform: rotate(180deg);
+    transform: rotate(-180deg);
 }