Re-add shared-styles

We have to copy shared-styles from gerrit core to apply the styles.

Change-Id: I15cd0591204dc950b2b2ea2cd067cb68e3642414

web/gr-zuul.ts

diff --git a/web/gr-zuul.ts b/web/gr-zuul.ts
index 9d28ab2..45c2918 100644
--- a/web/gr-zuul.ts
+++ b/web/gr-zuul.ts
@@ -18,6 +18,7 @@
 import {ChangeInfo, NumericChangeId} from '@gerritcodereview/typescript-api/rest-api';
 import {LitElement, html, css, nothing} from 'lit';
 import {customElement, property, state} from 'lit/decorators.js';
+import {sharedStyles} from './shared-styles';
 
 declare global {
   interface HTMLElementTagNameMap {
@@ -51,6 +52,7 @@
 
   static override get styles() {
     return [
+      sharedStyles,
       css`
         section.related-changes-section {
           margin-bottom: 1.4em;

web/shared-styles.ts

diff --git a/web/shared-styles.ts b/web/shared-styles.ts
new file mode 100644
index 0000000..fe53157
--- /dev/null
+++ b/web/shared-styles.ts
@@ -0,0 +1,184 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+// Copied from https://github.com/GerritCodeReview/gerrit/blob/cb0c3c82db2d1902facb5578cf22181cd64cd4af/polygerrit-ui/app/styles/shared-styles.ts
+import {css} from 'lit';
+
+export const sharedStyles = css`
+  /* CSS reset */
+
+  html,
+  body,
+  button,
+  div,
+  span,
+  applet,
+  object,
+  iframe,
+  h1,
+  h2,
+  h3,
+  h4,
+  h5,
+  h6,
+  p,
+  blockquote,
+  pre,
+  a,
+  abbr,
+  acronym,
+  address,
+  big,
+  cite,
+  code,
+  del,
+  dfn,
+  em,
+  img,
+  ins,
+  kbd,
+  q,
+  s,
+  samp,
+  small,
+  strike,
+  strong,
+  sub,
+  sup,
+  tt,
+  var,
+  b,
+  u,
+  i,
+  center,
+  dl,
+  dt,
+  dd,
+  ol,
+  ul,
+  li,
+  fieldset,
+  form,
+  label,
+  legend,
+  table,
+  caption,
+  tbody,
+  tfoot,
+  thead,
+  tr,
+  th,
+  td,
+  article,
+  aside,
+  canvas,
+  details,
+  embed,
+  figure,
+  figcaption,
+  footer,
+  header,
+  hgroup,
+  main,
+  menu,
+  nav,
+  output,
+  ruby,
+  section,
+  summary,
+  time,
+  mark,
+  audio,
+  video {
+    border: 0;
+    box-sizing: border-box;
+    font-size: 100%;
+    font: inherit;
+    margin: 0;
+    padding: 0;
+    vertical-align: baseline;
+  }
+  *::after,
+  *::before {
+    box-sizing: border-box;
+  }
+  a {
+    color: var(--link-color);
+  }
+  textarea,
+  select,
+  button {
+    font: inherit;
+  }
+  ol,
+  ul {
+    list-style: none;
+  }
+  blockquote,
+  q {
+    quotes: none;
+  }
+  blockquote:before,
+  blockquote:after,
+  q:before,
+  q:after {
+    content: '';
+    content: none;
+  }
+  table {
+    border-collapse: collapse;
+    border-spacing: 0;
+  }
+
+  /* Stopgap solution until we remove hidden$ attributes. */
+
+  :host([hidden]),
+  [hidden] {
+    display: none !important;
+  }
+  .separator {
+    border-left: 1px solid var(--border-color);
+    height: 20px;
+    margin: 0 8px;
+  }
+  .separator.transparent {
+    border-color: transparent;
+  }
+
+  /**
+   * TODO: Remove these rules and change (plugin) users to rely on
+   * gr-spinner-styles directly.
+   */
+  /** BEGIN: loading spiner */
+  .loadingSpin {
+    border: 2px solid var(--disabled-button-background-color);
+    border-top: 2px solid var(--primary-button-background-color);
+    border-radius: 50%;
+    width: 10px;
+    height: 10px;
+    animation: spin 2s linear infinite;
+    margin-right: var(--spacing-s);
+  }
+  @keyframes spin {
+    0% {
+      transform: rotate(0deg);
+    }
+    100% {
+      transform: rotate(360deg);
+    }
+  }
+  /** END: loading spiner */
+`;
+
+const $_documentContainer = document.createElement('template');
+$_documentContainer.innerHTML = `<dom-module id="shared-styles-zuul">
+  <template>
+    <style>
+    ${sharedStyles.cssText}
+    </style>
+  </template>
+</dom-module>`;
+document.head.appendChild($_documentContainer.content);
\ No newline at end of file