Updates all styles save for the tooltip and tracker, which are forthcoming. I just really wanted to commit all these changes.

WebHostLib/static/assets/check.js

@@ -0,0 +1,9 @@
+window.addEventListener('load', () => {
+    document.getElementById('check-button').addEventListener('click', () => {
+        document.getElementById('file-input').click();
+    });
+
+    document.getElementById('file-input').addEventListener('change', () => {
+        document.getElementById('check-form').submit();
+    });
+});