interface improvements

Co-authored-by: Alex <AlexanderMcDowell@users.noreply.github.com>

static/app.css

@@ -33,6 +33,14 @@ html {
     flex-direction: column;
 }
 
+#img-preview {
+    width: 18rem;
+}
+
+#pyro-eqn {
+    width: 800px;
+}
+
 .img-table-heading {
     padding: 4px 10px;
 }

static/img_preview.js

@@ -0,0 +1,11 @@
+function setOnchange() {
+    let imgPreview = document.getElementById('img-preview');
+    let imgUpload = document.getElementById('img-upload');
+    imgUpload.onchange = event => {
+        const [file] = imgUpload.files;
+        if (file) {
+            console.log(file)
+            imgPreview.src = URL.createObjectURL(file);
+        }
+    };
+}