diff --git a/web/menu.css b/web/menu.css
new file mode 100644
index 000000000..8d5cee607
--- /dev/null
+++ b/web/menu.css
@@ -0,0 +1,177 @@
+/* Copyright 2025 Mozilla Foundation
+ *
+ * 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
+ *
+ *     http://www.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.
+ */
+
+.popupMenu {
+  --menuitem-checkmark-icon: url(images/checkmark.svg);
+  --menu-mark-icon-size: 0;
+  --menu-icon-size: 16px;
+  --menuitem-gap: 5px;
+  --menuitem-border-color: transparent;
+  --menuitem-active-bg: color-mix(
+    in srgb,
+    var(--menu-text-color),
+    transparent 79%
+  );
+  --menuitem-text-active-fg: var(--menu-text-color);
+  --menuitem-focus-bg: color-mix(
+    in srgb,
+    var(--menu-text-color),
+    transparent 93%
+  );
+  --menuitem-focus-outline-color: light-dark(#0062fa, #00cadb);
+  --menuitem-focus-border-color: light-dark(white, black);
+
+  @media screen and (forced-colors: active) {
+    --menu-bg: Canvas;
+    --menu-background-blend-mode: normal;
+    --menu-box-shadow: none;
+    --menu-backdrop-filter: none;
+    --menu-text-color: ButtonText;
+    --menu-border-color: CanvasText;
+    --menuitem-border-color: none;
+    --menuitem-hover-bg: SelectedItemText;
+    --menuitem-text-hover-fg: SelectedItem;
+    --menuitem-active-bg: SelectedItemText;
+    --menuitem-text-active-fg: SelectedItem;
+    --menuitem-focus-outline-color: CanvasText;
+    --menuitem-focus-border-color: none;
+  }
+
+  display: flex;
+  flex-direction: column;
+  width: max-content;
+  height: auto;
+  position: relative;
+  left: 0;
+  top: 1px;
+  margin: 0;
+  padding: 5px;
+
+  background: var(--menu-bg);
+  background-blend-mode: var(--menu-background-blend-mode);
+  box-shadow: var(--menu-box-shadow);
+  border-radius: 6px;
+  border: 1px solid var(--menu-border-color);
+  backdrop-filter: var(--menu-backdrop-filter);
+
+  &.withMark {
+    --menu-mark-icon-size: 16px;
+  }
+
+  > li {
+    display: flex;
+    align-items: center;
+    list-style: none;
+    width: 100%;
+    height: 24px;
+    padding-inline: calc(var(--menu-mark-icon-size) + var(--menuitem-gap))
+      var(--menuitem-gap);
+    gap: var(--menuitem-gap);
+    box-sizing: border-box;
+    border-radius: var(--menuitem-border-radius);
+    border: 1px solid var(--menuitem-border-color);
+    background: transparent;
+
+    &:has(button.selected)::before {
+      content: "";
+      display: inline-block;
+      width: 11px;
+      height: 11px;
+      mask-repeat: no-repeat;
+      mask-position: center;
+      mask-image: var(--menuitem-checkmark-icon);
+      background-color: var(--menu-text-color);
+      position: absolute;
+      margin-left: -16px;
+    }
+
+    &:has(button:disabled) {
+      opacity: 0.62;
+      pointer-events: none;
+    }
+
+    &:hover {
+      background: var(--menuitem-hover-bg);
+      background-blend-mode: var(--menuitem-hover-background-blend-mode);
+      > button {
+        &:not(.noIcon)::before {
+          background-color: var(--menuitem-text-hover-fg);
+        }
+        > span {
+          color: var(--menuitem-text-hover-fg);
+        }
+      }
+      &:has(button.selected)::before {
+        background-color: var(--menuitem-text-hover-fg);
+      }
+    }
+
+    &:active {
+      background-color: var(--menuitem-active-bg);
+      > button > span {
+        color: var(--menuitem-text-active-fg);
+      }
+    }
+
+    &:has(> button:focus-visible) {
+      border-color: var(--menuitem-focus-border-color);
+      background-color: var(--menuitem-focus-bg);
+      outline: 2px solid var(--menuitem-focus-outline-color);
+      outline-offset: 2px;
+    }
+
+    > button {
+      display: flex;
+      flex-direction: row;
+      align-items: center;
+      width: 100%;
+      height: auto;
+      padding: var(--menuitem-gap);
+      gap: var(--menuitem-gap);
+      background: transparent;
+      border: none;
+
+      &:not(.noIcon)::before {
+        display: inline-block;
+        width: var(--menu-icon-size);
+        height: var(--menu-icon-size);
+        content: "";
+        mask-size: cover;
+        mask-position: center;
+        background-color: var(--menu-text-color);
+      }
+
+      &:focus-visible {
+        outline: none;
+      }
+
+      > span {
+        display: inline-block;
+        width: max-content;
+        height: auto;
+        text-align: left;
+        color: var(--menu-text-color);
+        user-select: none;
+        padding-inline-start: 6px;
+
+        font: menu;
+        font-size: 13px;
+        font-style: normal;
+        font-weight: 510;
+        line-height: normal;
+      }
+    }
+  }
+}
diff --git a/web/menu.js b/web/menu.js
new file mode 100644
index 000000000..508c2c303
--- /dev/null
+++ b/web/menu.js
@@ -0,0 +1,216 @@
+/* Copyright 2025 Mozilla Foundation
+ *
+ * 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
+ *
+ *     http://www.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.
+ */
+
+import { noContextMenu, stopEvent } from "pdfjs-lib";
+
+class Menu {
+  #triggeringButton;
+
+  #menu;
+
+  #menuItems;
+
+  #openMenuAC = null;
+
+  #menuAC = new AbortController();
+
+  #lastIndex = -1;
+
+  /**
+   * Create a menu for the given button.
+   * @param {HTMLElement} menuContainer
+   * @param {HTMLElement} triggeringButton
+   * @param {Array<HTMLElement>|null} menuItems
+   */
+  constructor(menuContainer, triggeringButton, menuItems) {
+    this.#menu = menuContainer;
+    this.#triggeringButton = triggeringButton;
+    if (Array.isArray(menuItems)) {
+      this.#menuItems = menuItems;
+    } else {
+      this.#menuItems = [];
+      for (const button of this.#menu.querySelectorAll("button")) {
+        this.#menuItems.push(button);
+      }
+    }
+    this.#setUpMenu();
+  }
+
+  /**
+   * Close the menu.
+   */
+  #closeMenu() {
+    if (!this.#openMenuAC) {
+      return;
+    }
+    const menu = this.#menu;
+    menu.classList.toggle("hidden", true);
+    this.#triggeringButton.ariaExpanded = "false";
+    this.#openMenuAC.abort();
+    this.#openMenuAC = null;
+    if (menu.contains(document.activeElement)) {
+      // If the menu is closed while focused, focus the actions button.
+      setTimeout(() => {
+        if (!menu.contains(document.activeElement)) {
+          this.#triggeringButton.focus();
+        }
+      }, 0);
+    }
+    this.#lastIndex = -1;
+  }
+
+  /**
+   * Set up the menu.
+   */
+  #setUpMenu() {
+    this.#triggeringButton.addEventListener("click", e => {
+      if (this.#openMenuAC) {
+        this.#closeMenu();
+        return;
+      }
+
+      const menu = this.#menu;
+      menu.classList.toggle("hidden", false);
+      this.#triggeringButton.ariaExpanded = "true";
+      this.#openMenuAC = new AbortController();
+      const signal = AbortSignal.any([
+        this.#menuAC.signal,
+        this.#openMenuAC.signal,
+      ]);
+      window.addEventListener(
+        "pointerdown",
+        ({ target }) => {
+          if (target !== this.#triggeringButton && !menu.contains(target)) {
+            this.#closeMenu();
+          }
+        },
+        { signal }
+      );
+      window.addEventListener("blur", this.#closeMenu.bind(this), { signal });
+    });
+
+    const { signal } = this.#menuAC;
+
+    this.#menu.addEventListener(
+      "keydown",
+      e => {
+        switch (e.key) {
+          case "Escape":
+            this.#closeMenu();
+            stopEvent(e);
+            break;
+          case "ArrowDown":
+          case "Tab":
+            this.#goToNextItem(e.target, true);
+            stopEvent(e);
+            break;
+          case "ArrowUp":
+          case "ShiftTab":
+            this.#goToNextItem(e.target, false);
+            stopEvent(e);
+            break;
+          case "Home":
+            this.#menuItems
+              .find(
+                item => !item.disabled && !item.classList.contains("hidden")
+              )
+              .focus();
+            stopEvent(e);
+            break;
+          case "End":
+            this.#menuItems
+              .findLast(
+                item => !item.disabled && !item.classList.contains("hidden")
+              )
+              .focus();
+            stopEvent(e);
+            break;
+        }
+      },
+      { signal, capture: true }
+    );
+    this.#menu.addEventListener("contextmenu", noContextMenu, { signal });
+    this.#menu.addEventListener("click", this.#closeMenu.bind(this), {
+      signal,
+      capture: true,
+    });
+    this.#triggeringButton.addEventListener(
+      "keydown",
+      ev => {
+        if (!this.#openMenuAC) {
+          return;
+        }
+        switch (ev.key) {
+          case "ArrowDown":
+          case "Home":
+            this.#menuItems
+              .find(
+                item => !item.disabled && !item.classList.contains("hidden")
+              )
+              .focus();
+            stopEvent(ev);
+            break;
+          case "ArrowUp":
+          case "End":
+            this.#menuItems
+              .findLast(
+                item => !item.disabled && !item.classList.contains("hidden")
+              )
+              .focus();
+            stopEvent(ev);
+            break;
+          case "Escape":
+            this.#closeMenu();
+            stopEvent(ev);
+        }
+      },
+      { signal }
+    );
+  }
+
+  /**
+   * Go to the next/previous menu item.
+   * @param {HTMLElement} element
+   * @param {boolean} forward
+   */
+  #goToNextItem(element, forward) {
+    const index =
+      this.#lastIndex === -1
+        ? this.#menuItems.indexOf(element)
+        : this.#lastIndex;
+    const len = this.#menuItems.length;
+    const increment = forward ? 1 : len - 1;
+    for (
+      let i = (index + increment) % len;
+      i !== index;
+      i = (i + increment) % len
+    ) {
+      const menuItem = this.#menuItems[i];
+      if (!menuItem.disabled && !menuItem.classList.contains("hidden")) {
+        menuItem.focus();
+        this.#lastIndex = i;
+        break;
+      }
+    }
+  }
+
+  destroy() {
+    this.#closeMenu();
+    this.#menuAC?.abort();
+    this.#menuAC = null;
+  }
+}
+
+export { Menu };
diff --git a/web/pdf_viewer.css b/web/pdf_viewer.css
index 66990399a..b4a5052f3 100644
--- a/web/pdf_viewer.css
+++ b/web/pdf_viewer.css
@@ -20,6 +20,7 @@
 /* Ignored in GECKOVIEW builds: */
 @import url(annotation_editor_layer_builder.css);
 @import url(sidebar.css);
+@import url(menu.css);
 
 :root {
   color-scheme: light dark;