diff --git a/package.json b/package.json
index 24e45e2..ea0ea4e 100644
--- a/package.json
+++ b/package.json
@@ -15,6 +15,8 @@
     "@types/react-dom": "^18.0.11",
     "debug": "^4.3.4",
     "monaco-editor": "^0.36.1",
+    "primeicons": "^6.0.1",
+    "primereact": "^9.2.1",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-stl-viewer": "^2.2.5",
diff --git a/public/index.html b/public/index.html
index aa2c8e6..ea06fb5 100644
--- a/public/index.html
+++ b/public/index.html
@@ -14,6 +14,12 @@
     
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/github-fork-ribbon-css/0.2.3/gh-fork-ribbon.min.css" />
 
+    <link rel="stylesheet" href="https://unpkg.com/primeicons/primeicons.css" />
+    <link rel="stylesheet" href="https://unpkg.com/primereact/resources/themes/lara-light-indigo/theme.css" />
+    <link rel="stylesheet" href="https://unpkg.com/primereact/resources/primereact.min.css" />
+    <link rel="stylesheet" href="https://unpkg.com/primeflex@3.2.1/primeflex.min.css" />
+
+
     <meta
       name="description"
       content="OpenSCAD Playground: edit .scad models and render them to STL from the browser (WebAssembly build OpenSCAD, with Monaco editor and STL Viewer)"
diff --git a/src/App.css b/src/App.css
index 272ed99..528765a 100644
--- a/src/App.css
+++ b/src/App.css
@@ -1,4 +1,4 @@
-.App {
+/* .App {
   text-align: center;
 }
 
@@ -42,4 +42,4 @@
   overflow-y: scroll;
   height: calc(min(200px, 30vh));
   position: relative;
-}
\ No newline at end of file
+} */
\ No newline at end of file
diff --git a/src/App.tsx b/src/App.tsx
index 9f1448e..ffb4a07 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -1,13 +1,19 @@
 // Portions of this file are Copyright 2021 Google LLC, and licensed under GPL2+. See COPYING.
 
-import React, { useContext, useEffect, useRef, useState } from 'react';
+import React, { forwardRef, useContext, useEffect, useRef, useState } from 'react';
 import {ModelContext, State} from './app-state'
 import Editor, { loader, Monaco } from '@monaco-editor/react';
-import './App.css';
+// import './App.css';
 import openscadEditorOptions from './language/openscad-editor-options';
 import { Model } from './model';
 import * as monaco from 'monaco-editor/esm/vs/editor/editor.api';
 import {StlViewer} from "react-stl-viewer";
+import { Button } from 'primereact/button';
+import { ProgressBar } from 'primereact/progressbar';
+
+// import "primereact/resources/themes/lara-light-indigo/theme.css";
+// import "primereact/resources/primereact.min.css";
+// import "primeicons/primeicons.css"; 
 
 let monacoInstance: Monaco
 loader.init().then(mi => monacoInstance = mi);
@@ -31,13 +37,13 @@ function EditorPanel() {
         monaco.KeyMod.CtrlCmd | monaco.KeyCode.Enter,
         monaco.KeyCode.F6,
       ],
-      run: () => model.render({isPreview: false})
+      run: () => model.render({isPreview: false, now: true})
     });
     editor.addAction({
       id: "openscad-preview",
       label: "Preview OpenSCAD",
       keybindings: [monaco.KeyCode.F5],
-      run: () => model.render({isPreview: false})
+      run: () => model.render({isPreview: true, now: true})
     });
     setEditor(editor)
   }
@@ -79,7 +85,7 @@ export function App({initialState}: {initialState: State}) {
   const model = new Model(state, setState);
   useEffect(() => model.init());
 
-  const stlModelRef = useRef(null);
+  // const stlModelRef = forwardRef();
   
   return (
     <ModelContext.Provider value={model}>
@@ -88,41 +94,50 @@ export function App({initialState}: {initialState: State}) {
           <div style={{width: "50vw"}}>
             <EditorPanel/>
           </div>
-          {state.output?.stlFileURL &&
-            <StlViewer
-                style={{
-                  flex: 1
-                }}
-                ref={stlModelRef}
-                showAxes={true}
-                orbitControls
-                shadows
-                modelProps={{
-                  color: '#f9d72c',
+          <div style={{display: 'flex', flexDirection: 'column', flex: 1, position: 'relative'}}>
+            {(state.rendering || state.previewing) &&
+              <ProgressBar mode="indeterminate" style={{ height: '6px' }}></ProgressBar>}
+            {state.output?.stlFileURL &&
+              <StlViewer
+                  style={{
+                    flex: 1
+                  }}
+                  // ref={stlModelRef}
+                  showAxes={true}
+                  orbitControls
+                  shadows
+                  modelProps={{
+                    color: '#f9d72c',
+
+                  }}
+                  url={state.output?.stlFileURL ?? ''}
+                  />
+            }
 
-                }}
-                url={state.output?.stlFileURL ?? ''}
-                />
-          }
           </div>
-        <div style={{display: 'flex', flexDirection: 'row'}}>
-            <button onClick={() => model.render({isPreview: false})}>Render</button>
-            {model.state.previewing && 'previewing... '}
-            {model.state.rendering && 'rendering... '}
-            {model.state.checkingSyntax && 'checking syntax... '}
+        </div>
+        <div style={{display: 'flex', flexDirection: 'row', gap: '10px'}}>
+            <Button onClick={() => model.render({isPreview: false, now: true})}>Render</Button>
+            {state.output && state.output.formattedElapsedMillis}
+            &nbsp;
+            {state.previewing && 'previewing... '}
+            {state.rendering && 'rendering... '}
+            {state.checkingSyntax && 'checking syntax... '}
+
+            {state.output && (
+              <a href={state.output.stlFileURL}
+              target="_blank" 
+              download={state.output.isPreview ? "preview.stl" : "render.stl"}
+              title="STL Download">
+                  {state.output.isPreview ? "preview.stl" : "render.stl"} ({state.output.formattedStlFileSize})
+              </a>
+            )}
 
             <span style={{flex: 1}}></span>
             
             <a target="_blank" className="text-fragment" href="http://openscad.org/documentation.html">Docs</a> |
             <a target="_blank" className="text-fragment" href="http://openscad.org/cheatsheet/">Cheatsheet</a> |
             <a target="_blank" href="https://github.com/openscad/openscad-playground/blob/rewrite1/LICENSE.md">LICENSES</a>
-
-            {state.output?.stlFileURL && (
-              <a href={state.output?.stlFileURL}
-                title="STL Download">
-                  Download Model
-              </a>
-            )}
         </div>
       </div>
     </ModelContext.Provider>
diff --git a/src/actions.ts b/src/actions.ts
index 37f9e93..8167a36 100644
--- a/src/actions.ts
+++ b/src/actions.ts
@@ -36,7 +36,7 @@ export const checkSyntax =
   });
 
 var renderDelay = 1000;
-export type RenderOutput = {stlFile: File, logText: string, markers: monaco.editor.IMarkerData[], elapsedMillis?: number}
+export type RenderOutput = {stlFile: File, logText: string, markers: monaco.editor.IMarkerData[], elapsedMillis: number}
 
 export type RenderArgs = {
   source: string,
@@ -45,23 +45,26 @@ export type RenderArgs = {
   isPreview: boolean
 }
 export const render =
- turnIntoDelayableExecution(renderDelay, (args: RenderArgs) => {
-  
-    const prefixLines: string[] = [];
-    if (args.isPreview) prefixLines.push('$preview=false;');
-    const source = args.isPreview ? [...prefixLines, args.source].join('\n') : args.source
+ turnIntoDelayableExecution(renderDelay, (params: RenderArgs) => {
     const inputFile = 'input.scad';
+    const args = [
+      inputFile,
+      "-o", "out.stl",
+      "--export-format=binstl",
+      ...(params.features ?? []).map(f => `--enable=${f}`),
+      ...(params.extraArgs ?? [])
+    ]
+
+    const prefixLines: string[] = [];
+    if (params.isPreview) {
+      prefixLines.push('$preview=true;');
+    }
+    const source = [...prefixLines, params.source].join('\n');
     
     const job = spawnOpenSCAD({
       // wasmMemory,
       inputs: [['input.scad', source]],
-      args: [
-        inputFile,
-        "-o", "out.stl",
-        "--export-format=binstl",
-        ...(args.features ?? []).map(f => `--enable=${f}`),
-        ...(args.extraArgs ?? [])
-      ],
+      args,
       outputPaths: ['out.stl']
     });
 
diff --git a/src/app-state.ts b/src/app-state.ts
index 7d6d2a2..b072ad8 100644
--- a/src/app-state.ts
+++ b/src/app-state.ts
@@ -22,6 +22,9 @@ export interface State {
     isPreview: boolean,
     stlFile: File,
     stlFileURL: string,
+    elapsedMillis: number,
+    formattedElapsedMillis: string,
+    formattedStlFileSize: string,
   },
 };
 
diff --git a/src/default-scad.ts b/src/default-scad.ts
index e5a93ca..e99a60a 100644
--- a/src/default-scad.ts
+++ b/src/default-scad.ts
@@ -13,5 +13,5 @@ translate([10, 10, 10])
 //
 // include <BOSL2/std.scad>
 // translate([-100, 0, 0])
-	spheroid(d=100, style="icosa", $fn=20);
+//   spheroid(d=100, style="icosa", $fn=20);
 `
\ No newline at end of file
diff --git a/src/index.css b/src/index.css
index ec2585e..9529ee9 100644
--- a/src/index.css
+++ b/src/index.css
@@ -1,8 +1,9 @@
 body {
   margin: 0;
-  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
+  font-family: (--font-family);
+  /* font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
     'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
-    sans-serif;
+    sans-serif; */
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
 }
diff --git a/src/model.ts b/src/model.ts
index 0f92fc0..9fb5c9a 100644
--- a/src/model.ts
+++ b/src/model.ts
@@ -42,7 +42,7 @@ export class Model {
 
   private processSource() {
     this.checkSyntax();
-    this.render({isPreview: true});
+    this.render({isPreview: true, now: false});
   }
   checkSyntax() {
     this.mutate(s => s.checkingSyntax = true);
@@ -52,7 +52,7 @@ export class Model {
     })});
   }
 
-  render({isPreview}: {isPreview: boolean}) {
+  render({isPreview, now}: {isPreview: boolean, now: boolean}) {
     const setRendering = (s: State, value: boolean) => {
       if (isPreview) {
         s.previewing = value;
@@ -64,9 +64,10 @@ export class Model {
 
     const source = this.state.params.source;
     const features = this.state.params.features;
-    const renderArgs = {source, features, extraArgs: ['-D$preview=true'], isPreview};
+    const renderArgs = {source, features, extraArgs: [], isPreview};
+    // console.log('renderArgs', renderArgs);
 
-    render(renderArgs)({now: !isPreview, callback: output => {
+    render(renderArgs)({now, callback: output => {
       this.mutate(s => {
         s.lastCheckerRun = {
           logText: output.logText,
@@ -75,10 +76,14 @@ export class Model {
         if (s.output?.stlFileURL) {
           URL.revokeObjectURL(s.output.stlFileURL);
         }
+
         s.output = {
           isPreview: isPreview,
           stlFile: output.stlFile,
           stlFileURL: URL.createObjectURL(output.stlFile),
+          elapsedMillis: output.elapsedMillis,
+          formattedElapsedMillis: formatMillis(output.elapsedMillis),
+          formattedStlFileSize: formatBytes(output.stlFile.size),
         };
         setRendering(s, false);
       });
@@ -86,3 +91,22 @@ export class Model {
   }
 
 }
+
+function formatBytes(n: number) {
+  if (n < 1024) {
+    return `${Math.floor(n)} bytes`;
+  }
+  n /= 1024;
+  if (n < 1024) {
+    return `${Math.floor(n * 10) / 10} kB`;
+  }
+  n /= 1024;
+  return `${Math.floor(n * 10) / 10} MB`;
+}
+
+function formatMillis(n: number) {
+  if (n < 1000)
+    return `${Math.floor(n)} millis`;
+
+  return `${Math.floor(n / 100) / 10} sec`;
+}
\ No newline at end of file
diff --git a/src/openscad-runner.ts b/src/openscad-runner.ts
index f902a9c..94cafaa 100644
--- a/src/openscad-runner.ts
+++ b/src/openscad-runner.ts
@@ -27,7 +27,7 @@ export type OpenSCADInvocationResults = {
   error?: string,
   outputs?: [string, string][],
   mergedOutputs: MergedOutputs,
-  elapsedMillis?: number,
+  elapsedMillis: number,
 }
 
 export function spawnOpenSCAD({inputs, args, outputPaths}: OpenSCADInvocation): AbortablePromise<OpenSCADInvocationResults> {
diff --git a/webpack.config.js b/webpack.config.js
index b83fa6d..98b98d8 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -15,9 +15,16 @@ module.exports = {
       {
         test: /\.css$/i,
         use: [
-         {loader: 'css-loader', options:{url: false}}
+         {
+          loader: 'css-loader',
+          options:{url: false},
+        }
         ]
-      }
+      },
+      {
+        test: /\.(png|gif|woff|woff2|eot|ttf|svg)$/,
+        loader: "url-loader?limit=100000"
+      },
     ],
   },
   resolve: {