Markup / scss refactor WIP

- Scroll on tree;
- Class renaming pane > l-pane;
- Refinements to collapsed state, WIP

src/ui/components/layout/Layout.vue

@@ -8,7 +8,7 @@
                 <div class="l-shell__search">
                     <search class="c-search--major" ref="shell-search"></search>
                 </div>
-                <div class="l-shell__tree u-last">
+                <div class="l-shell__tree">
                     <MctTree ref="shell-tree"></MctTree>
                 </div>
             </pane>
@@ -57,6 +57,10 @@
             order: 2;
         }
 
+        &__tree {
+            flex: 1 1 100%;
+        }
+
         &__object-view {
             flex: 1 1 auto;
             padding: $interiorMarginLg;

src/ui/components/layout/MctTree.vue

@@ -22,8 +22,12 @@
     @import "~styles/sass-base";
 
     .c-tree {
+        overflow-x: hidden;
+        overflow-y: auto;
+        height: 100%;
+
         .c-tree {
-            display: none;
+            display: none; // Will be overridden when in an expanded tree node.
             margin-left: 20px;
         }