Fix popup changelist header/footer position

jet/static/jet/css/_changelist.scss

@@ -393,11 +393,15 @@
 
   &.fixed {
     position: fixed;
-    left: 250px + 20px;
+    left: $sidebar-width + 20px;
     right: 20px;
     bottom: 0;
     border-top: 2px solid $content-border2-color;
 
+    body.popup & {
+      left: 20px;
+    }
+
     @include for-mobile {
       position: static;
       left: auto;

jet/static/jet/css/_tables.scss

@@ -22,6 +22,10 @@ table {
     border-radius: 0;
     box-shadow: none;
 
+    body.popup & {
+      left: 20px;
+    }
+
     @include for-mobile {
       display: none !important;
     }