Increase space panel collapse clickable area (#6084)

res/css/structures/_SpacePanel.pcss

@@ -101,6 +101,8 @@ $activeBorderColor: $primary-content;
 
     .mx_SpaceItem.collapsed {
         & > .mx_SpaceButton > .mx_SpaceButton_toggleCollapse {
+            padding: 0 10px;
+            margin: 0 -10px;
             transform: rotate(-90deg);
         }
 
@@ -161,6 +163,7 @@ $activeBorderColor: $primary-content;
 
         .mx_SpaceButton_toggleCollapse {
             width: $gutterSize;
+            padding: 10px 0;
             min-width: $gutterSize;
             height: 20px;
             mask-position: center;