diff --git a/src/_js/main.mjs b/src/_js/main.mjs
deleted file mode 100644
index ea3e9c44..00000000
--- a/src/_js/main.mjs
+++ /dev/null
@@ -1,73 +0,0 @@
-// Copyright 2018 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the “License”);
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-// <https://apache.org/licenses/LICENSE-2.0>.
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an “AS IS” BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-const darkModeToggle = document.querySelector('dark-mode-toggle');
-
-// Toggles the `dark` class based on the dark mode toggle’s mode.
-const root = document.documentElement;
-const updateThemeClass = () => {
-  root.classList.toggle('dark', darkModeToggle.mode === 'dark');
-};
-
-// Set or remove the `dark` class the first time.
-updateThemeClass();
-
-// Listen for toggle changes (which includes `prefers-color-scheme` changes)
-// and toggle the `dark` class accordingly.
-darkModeToggle.addEventListener('colorschemechange', updateThemeClass);
-
-// Navigation toggle.
-const navToggle = document.querySelector('#nav-toggle');
-navToggle.addEventListener('click', (event) => {
-  event.preventDefault();
-  document.querySelector('header nav').classList.add('show');
-  navToggle.classList.add('hide');
-});
-
-// A user right-clicking the logo probably wants to download it.
-if (location.pathname !== '/logo') {
-  const logo = document.querySelector('#header a');
-  logo.addEventListener('contextmenu', (event) => {
-    event.preventDefault();
-    self.location = '/logo';
-  });
-}
-
-// Remove any existing service worker
-navigator.serviceWorker.getRegistrations().then((registrations) => {
-  for(let registration of registrations) {
-    registration.unregister();
-  }
-});
-
-// Remove UTM garbage from URLs, to make it less likely such links get shared.
-if (location.search.includes('utm_source')) {
-  // This site doesn’t use query string parameters anyway, so we can just
-  // set the location to `location.pathname` directly.
-  history.replaceState({}, '', location.pathname);
-}
-
-// Google Analytics.
-const UA_ID = 'UA-65961526-1';
-self.GoogleAnalyticsObject = 'ga';
-self.ga = (...args) => {
-  ga.q.push(args);
-};
-ga.l = Date.now();
-ga.q = [];
-ga('create', UA_ID, 'auto');
-ga('set', 'referrer', document.referrer.split('?')[0]);
-ga('send', 'pageview');
-const gaScript = document.createElement('script');
-gaScript.src = 'https://www.google-analytics.com/analytics.js';
-document.head.appendChild(gaScript);