diff --git a/app/covid-calculator.ipynb b/app/covid-calculator.ipynb
index 30531563..44fef497 100644
--- a/app/covid-calculator.ipynb
+++ b/app/covid-calculator.ipynb
@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 1,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -11,7 +11,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 2,
    "metadata": {
     "pycharm": {
      "name": "#%%\n"
@@ -23,12 +23,13 @@
     "                         w.Text(placeholder=\"E.g. Workshop without masks\", description=\"Simulation name:\",\n",
     "                                style={'description_width': '35%'}),\n",
     "                         w.Text(placeholder=\"E.g. 17/R-033\", description=\"Room number:\",\n",
-    "                                style={'description_width': '35%'})))"
+    "                                style={'description_width': '35%'})),\n",
+    "                   layout=w.Layout(padding='0px 0px 50px 0px'))"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 3,
    "metadata": {
     "pycharm": {
      "name": "#%%\n"
@@ -41,7 +42,8 @@
     "height_text = w.Text(placeholder=\"Room ceiling height (m²)\", description=\"Ceiling height\")\n",
     "\n",
     "room_dimensions_box = w.VBox(children=(volume_text, w.Label(value=\"------- OR -------\"),area_text, height_text),\n",
-    "                             layout=w.Layout(align_items='center'))\n",
+    "                             layout=w.Layout(padding='0px 0px 50px 0px'))\n",
+    "\n",
     "def manage_room_text_fields(_):\n",
     "    volume_text.disabled = bool(area_text.value) or bool(height_text.value)\n",
     "    area_text.disabled = bool(volume_text.value)\n",
@@ -49,7 +51,7 @@
     "\n",
     "for text in [volume_text, area_text, height_text]:\n",
     "    text.observe(manage_room_text_fields)\n",
-    "    text.style.description_width = \"50%\"\n",
+    "    text.style.description_width = \"auto\"\n",
     "\n",
     "volume_text.observe(manage_room_text_fields)\n",
     "area_text.observe(manage_room_text_fields)\n",
@@ -58,26 +60,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 145,
+   "execution_count": 197,
    "metadata": {
     "pycharm": {
      "name": "#%%\n"
     }
    },
-   "outputs": [
-    {
-     "data": {
-      "text/plain": "VBox(children=(VBox(children=(Label(value='Ventilation type:'), HBox(children=(ToggleButton(value=False, descr…",
-      "application/vnd.jupyter.widget-view+json": {
-       "version_major": 2,
-       "version_minor": 0,
-       "model_id": "ac7739af0c0d456db756d4844a8f1b41"
-      }
-     },
-     "metadata": {},
-     "output_type": "display_data"
-    }
-   ],
+   "outputs": [],
    "source": [
     "ventilation_label = w.Label(\"Ventilation type:\")\n",
     "mechanical_button = w.ToggleButton(value=False, description='Mechanical', layout={'width': 'auto'})\n",
@@ -105,49 +94,59 @@
     "            w.RadioButtons(options=('Always', '15 min / 2h'))\n",
     "        ))\n",
     "    ),\n",
-    "    layout=w.Layout(align_items='center', display='none'),\n",
+    "    layout=w.Layout(display='none'),\n",
     ")\n",
     "\n",
     "\n",
     "\n",
     "tab_bar = w.HBox(children=(mechanical_button, natural_button))\n",
-    "ventilation_type_menu = w.VBox(children=(ventilation_label, tab_bar), layout=w.Layout(align_items='center', width='auto'))\n",
-    "ventilation_menu = w.VBox(children=(ventilation_type_menu, mech_vent_box, nat_vent_box),\n",
-    "                          layout=w.Layout(align_items='center'))\n",
+    "ventilation_type_menu = w.VBox(children=(ventilation_label, tab_bar), layout=w.Layout(padding='0px 0px 20px 0px'))\n",
+    "ventilation_box = w.VBox(children=(ventilation_type_menu, mech_vent_box, nat_vent_box),\n",
+    "                         layout=w.Layout(padding='0px 0px 50px 0px'))\n",
     "\n",
     "def handle_natural_toggle(_):\n",
     "    if natural_button.value:\n",
     "        mechanical_button.value = False\n",
-    "        ventilation_menu.children[2].layout.display = 'block'\n",
+    "        ventilation_box.children[2].layout.display = 'block'\n",
     "    else:\n",
-    "        ventilation_menu.children[2].layout.display = 'none'\n",
+    "        ventilation_box.children[2].layout.display = 'none'\n",
     "\n",
     "def handle_mechanical_toggle(_):\n",
     "    if mechanical_button.value:\n",
     "        natural_button.value = False\n",
-    "        ventilation_menu.children[1].layout.display = 'block'\n",
+    "        ventilation_box.children[1].layout.display = 'block'\n",
     "    else:\n",
-    "        ventilation_menu.children[1].layout.display = 'none'\n",
+    "        ventilation_box.children[1].layout.display = 'none'\n",
     "\n",
     "natural_button.observe(handle_natural_toggle)\n",
-    "mechanical_button.observe(handle_mechanical_toggle)\n",
-    "\n",
-    "ventilation_menu"
+    "mechanical_button.observe(handle_mechanical_toggle)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "outputs": [],
-   "source": [
-    "natural_button = w.ToggleButton(value=False, description='Mechanical ventilation', layout={'width': '100%'})\n"
-   ],
+   "execution_count": 196,
    "metadata": {
-    "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
+   },
+   "outputs": [
+    {
+     "data": {
+      "text/plain": "VBox(children=(VBox(children=(HTML(value='<font size=\"+2\"><b>CARA</b> Covid Calculator</font>'), Text(value=''…",
+      "application/vnd.jupyter.widget-view+json": {
+       "version_major": 2,
+       "version_minor": 0,
+       "model_id": "06f418553b6d45448e35303e41b1ebb7"
+      }
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    }
+   ],
+   "source": [
+    "w.VBox(children=(intro_box, room_dimensions_box, ventilation_box))"
+   ]
   }
  ],
  "metadata": {