Enhancement: Added drop shadows to markdown, text, and tree views

packages/application/style/base.css

@@ -80,6 +80,10 @@ body[data-notebook='edit'] #spacer-widget-bottom {
   box-shadow: var(--jp-elevation-z4);
 }
 
+.jp-TreePanel > .lm-TabPanel-stackedPanel {
+  box-shadow: var(--jp-elevation-z4);
+}
+
 body[data-notebook='notebooks'] #main-panel {
   margin-left: unset;
   margin-right: unset;
@@ -89,3 +93,13 @@ body[data-notebook='notebooks'] #main-panel {
 body[data-notebook='notebooks'] #spacer-widget-top {
   min-height: unset;
 }
+
+#main-panel > .jp-TreePanel {
+  padding: 0px 5px;
+}
+
+@media only screen and (max-width: 760px) {
+  #main-panel > .jp-TreePanel {
+    margin: 0px -5px;
+  }
+}

packages/notebook-extension/style/base.css

@@ -152,11 +152,7 @@ body[data-notebook='notebooks'] .jp-WindowedPanel-window {
 /* Notebook box shadow */
 
 body[data-notebook='notebooks'] .jp-Notebook > *:first-child:not(:last-child) {
-  box-shadow: 0px 0px 12px 1px var(--jp-shadow-umbra-color);
-}
-
-body[data-notebook='notebooks'] .jp-Notebook > *:first-child:not(:last-child) {
-  box-shadow: 0px 0px 12px 1px var(--jp-shadow-umbra-color);
+  box-shadow: var(--jp-elevation-z4);
 }
 
 body[data-notebook='notebooks']