diff --git a/test.php b/test.php
new file mode 100644
index 0000000..10aed56
--- /dev/null
+++ b/test.php
@@ -0,0 +1,47 @@
+<?php
+/*require_once("core.php");
+
+$element = "Gtfs\CalendarDate";
+
+$item = new $element([
+  "service_id" => "a",
+  "date" => "b",
+  "exception_type" => Gtfs\CalendarDate\ExceptionType::ADDED
+]);
+
+//$feed->setServiceId(Gtfs\CalendarDate\ExceptionType::ADDED);
+
+var_dump(json_decode($item->serializeToJsonString(), true));
+*/
+?>
+
+<!DOCTYPE html>
+<html>
+  <head>
+    <style>
+    @media (orientation: landscape) {
+      :root {
+        --size: 4vh;
+      }
+    }
+
+    @media (orientation: portrait) {
+      :root {
+        --size: 4vw;
+      }
+    }
+
+    .a {
+      font-size: calc(4 * var(--size));
+      background: cyan;
+      width: 400px;
+      height: 400px;
+    }
+    </style>
+  </head>
+  <body>
+    <div class="a">
+      Adri
+    </div>
+  </body>
+</html>