sidebar: reduce breakpoint to 630pt, reduce width to 320pt

lib/sidebar.js

@@ -22,7 +22,7 @@ define([], function () {
       if (sidebar.classList.contains("hidden"))
           return 0
 
-      var small = window.matchMedia("(max-width: 60em)")
+      var small = window.matchMedia("(max-width: 630pt)")
       return small.matches ? 0 : sidebar.offsetWidth
     }
 

scss/main.scss

@@ -3,9 +3,9 @@
 @import '_leaflet';
 @import '_leaflet.label';
 
-$minscreenwidth: 60em;
+$minscreenwidth: 630pt;
 $sidebarwidth: 420pt;
-$sidebarwidthsmall: 360pt;
+$sidebarwidthsmall: 320pt;
 $buttondistance: 12pt;
 
 @import '_sidebar';