Update notebooks with widget dark mode fixes

Author: nking-1

notebook-processor/custom_template/index.html.j2

@@ -144,14 +144,20 @@
   .rendered_html tbody tr:nth-child(odd) {
     background: #282F3E;
   }
+
   .rendered_html tbody tr:nth-child(even) {
     background: #1A1E2B;
   }
+
   /* Add some padding to table cells for better readability */
   .rendered_html td, .rendered_html th {
     padding: 8px 12px;
   }
 
+  div.input_area {
+    background-color: #151922;
+  }
+
 </style>
 
 <script>