New source found from dndbeyond.com

ddb_main/tools/js/smartComponents/ArmorClassBox/ArmorClassBox.tsx

@@ -1,8 +1,9 @@
-import { visuallyHidden } from "@mui/utils";
 import * as React from "react";
 
 import { CharacterTheme } from "@dndbeyond/character-rules-engine/es";
 
+import a11yStyles from "~/styles/accessibility.module.css";
+
 import BoxBackground from "../BoxBackground";
 import ArmorClassBoxSvg from "../Svg/boxes/ArmorClassBoxSvg";
 
@@ -36,7 +37,7 @@ export default class ArmorClassBox extends React.PureComponent<Props> {
     return (
       <section className={classNames.join(" ")} onClick={this.handleClick}>
         <BoxBackground StyleComponent={ArmorClassBoxSvg} theme={theme} />
-        <h2 style={visuallyHidden}>Armor Class</h2>
+        <h2 className={a11yStyles.screenreaderOnly}>Armor Class</h2>
         <div
           className={`ddbc-armor-class-box__label ${
             theme.isDarkMode ? "ddbc-armor-class-box__label--dark-mode" : ""