Two bindings.
One controller.

import { StrictMode } from "react";
import { createRoot } from "react-dom/client";
import { DisplayWidget } from "openregard/display/react";
import type { DisplayController } from "openregard/display";
const regard = (window as unknown as { regard: DisplayController }).regard;
createRoot(document.getElementById("react-controls")!).render(
  <StrictMode>
    <DisplayWidget display={regard} className="demo-widget" />
  </StrictMode>,
);
(
  window as unknown as {
    OpenRegardDisplay: {
      mountDisplayWidget: (
        el: HTMLElement,
        r: DisplayController,
        options?: { className: string },
      ) => void;
    };
  }
).OpenRegardDisplay.mountDisplayWidget(
  document.getElementById("controls")!,
  regard,
  {
    className: "demo-widget",
  },
);

<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width,initial-scale=1" />
    <title>React binding — Open Regard Display</title>
    <!-- Self-host synchronous scripts so the saved profile applies before paint. -->
    <script src="../dist/display.browser.js"></script>
    <script src="../dist/presets.browser.js"></script>
    <script src="./config.js"></script>
    <link rel="stylesheet" href="../dist/style.css" />
    <link rel="stylesheet" href="./demo.css" />
    <link rel="icon" href="./mark.svg" type="image/svg+xml" />
  </head>
  <body>
    <a class="skip" href="#main">Skip to content</a>
    <header class="masthead shell">
      <a class="brand" href="https://openregard.org/"
        ><img src="./mark.svg" alt="" />open regard.</a
      >
      <span class="meta">Module 01 / Display / Runnable examples</span>
    </header>
    <nav class="example-nav shell" aria-label="Example navigation">
      <a href="./">Vanilla HTML</a><a href="./docs.html">Static docs</a
      ><a href="./react.html" aria-current="page">React</a
      ><a href="https://openregard.org/docs/">Library documentation ↗</a>
    </nav>
    <main id="main" class="shell">
      <section class="hero">
        <div>
          <p class="eyebrow">03 / React + vanilla</p>
          <h1>Two bindings.<br /><em>One controller.</em></h1>
          <p class="intro">
            The React widget in this panel shares the controller that was
            started before paint. Change it here or in the vanilla control
            below; both update together.
          </p>
        </div>
        <aside class="control-card" aria-label="Display settings">
          <p class="eyebrow">Try a display profile</p>
          <div id="react-controls"></div>
        </aside>
      </section>

      <div class="section-head">
        <h2>Use Display inside a React app</h2>
        <p>Optional binding · Shared state · Site-owned CSS</p>
      </div>
      <div class="grid">
        <article class="card">
          <p class="eyebrow">React binding</p>
          <h2>Subscribe, then render.</h2>
          <p>
            <code>DisplayWidget</code> uses the same native markup and public
            CSS hooks as the vanilla widget. Pass <code>className</code> to
            scope your design; keep the controller stable between renders.
          </p>
          <pre class="code-note"><code>&lt;DisplayWidget
  display={regard}
  className="demo-widget"
/&gt;</code></pre>
        </article>
        <article class="card">
          <p class="eyebrow">Vanilla binding</p>
          <h2>Same profile. No bridge.</h2>
          <p>
            This control is mounted directly into the DOM. It shares the
            existing controller with React.
          </p>
          <div id="controls"></div>
        </article>
      </div>
      <section class="sync-row">
        <div>
          <p class="eyebrow">A shared configuration</p>
          <h2>Presets work in both bindings.</h2>
        </div>
        <p>
          Composition happens in <strong>config.js</strong>, outside React.
          Vision adds text-spacing tokens; Vision + High Contrast adds paired
          colors and borders. Both widgets inherit the page’s new presentation.
        </p>
      </section>

      
    </main>
    <footer class="shell">
      <p>
        Open Regard / Display. Profiles and page styles are configured by the
        site. Test your integration with your content and users.
      </p>
      <a href="https://github.com/inferal-oss/openregard">View the project ↗</a>
    </footer>
    <script src="../dist/react-demo.js" defer></script>
  </body>
</html>

// Optional token recipes. Profile names, composition and site styling are yours.
const { wcagPresets, htmlPresets } = OpenRegardPresets;
window.regardConfig = {
  version: 1,
  defaultProfile: "standard",
  storageKey: "openregard-example",
  controlLabel: "Reading and display preferences",
  profiles: [
    {
      id: "standard",
      label: "Standard",
      description: "The original site presentation.",
    },
    {
      id: "roomy",
      label: "Vision",
      description: "Larger text with the WCAG text-spacing override values.",
      tokens: {
        ...wcagPresets.textSpacing,
        ...htmlPresets.nativeControls,
        "--regard-font-size": "125%",
      },
    },
    {
      id: "vision-contrast",
      label: "Vision + High Contrast",
      description:
        "Larger, spaced text with a restrained palette and stronger borders.",
      tokens: {
        ...wcagPresets.textSpacing,
        ...wcagPresets.contrastLight,
        ...htmlPresets.nativeControls,
        "--regard-font-size": "125%",
      },
    },
    {
      id: "strong",
      label: "Max Contrast",
      description:
        "Larger text, generous spacing and black-and-white surfaces.",
      tokens: {
        ...wcagPresets.textSpacing,
        ...htmlPresets.nativeControls,
        "--regard-font-size": "150%",
        "--regard-page-ink": "#000",
        "--regard-page-paper": "#fff",
        "--regard-panel-ink": "#fff",
        "--regard-panel-paper": "#000",
        "--regard-border-color": "#000",
      },
    },
  ],
};
window.regard = OpenRegardDisplay.createDisplay(window.regardConfig);
window.stopRegard = window.regard.start();

:root {
  font-size: var(--regard-font-size, 100%);
  --ink: var(--regard-page-ink, #203b32);
  --paper: var(--regard-page-paper, #f4f5ee);
  --muted: var(--regard-page-ink, #52645b);
  --line: var(--regard-border-color, #c5cec0);
  --panel-paper: var(--regard-panel-paper, #203b32);
  --panel-ink: var(--regard-panel-ink, #f4f7ee);
  --surface: var(--regard-page-paper, #fffef8);
  --accent: var(--regard-page-paper, #d8ebbb);
  color: var(--ink);
  background: var(--paper);
  font-family:
    ui-sans-serif,
    system-ui,
    -apple-system,
    sans-serif;
  line-height: var(--regard-line-height, 1.65);
  letter-spacing: var(--regard-letter-spacing, normal);
  word-spacing: var(--regard-word-spacing, normal);
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  overflow-wrap: anywhere;
}
.shell {
  width: min(100% - 3rem, 76rem);
  margin-inline: auto;
}
a {
  color: inherit;
  text-underline-offset: 0.25em;
}
:focus-visible {
  outline: 3px solid currentColor;
  outline-offset: 4px;
}
.skip {
  position: absolute;
  transform: translateY(-150%);
  background: Canvas;
  color: CanvasText;
  padding: 0.7em;
  z-index: 5;
}
.skip:focus {
  transform: none;
}
.masthead {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  justify-content: space-between;
  align-items: center;
  padding-block: 1.5rem;
}
.brand {
  display: inline-flex;
  gap: 0.65em;
  align-items: center;
  font-weight: 700;
  font-size: 1.3rem;
  letter-spacing: -0.04em;
  text-decoration: none;
}
.brand img {
  width: 2rem;
  height: 2rem;
}
.masthead .meta {
  font-size: 0.75rem;
  color: var(--muted);
}
.example-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem 1.5rem;
  padding-block: 0.8rem;
  border-block: 1px solid var(--line);
  font-size: 0.85rem;
}
.example-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 2.75em;
  text-decoration: none;
}
.example-nav [aria-current] {
  font-weight: 700;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 0.55em;
}
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: clamp(2rem, 5vw, 5rem);
  padding-block: 3.5rem;
  align-items: start;
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.7rem;
  font-weight: 700;
}
h1 {
  font-size: clamp(2.4rem, 5vw, 4.4rem);
  line-height: 1.1;
  letter-spacing: -0.055em;
  margin: 0.8rem 0 1.5rem;
  font-weight: 600;
}
h1 em {
  font-family: Georgia, serif;
  font-weight: 400;
}
h2 {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  line-height: 1.2;
  letter-spacing: -0.035em;
  font-weight: 600;
  margin-top: 0;
}
h3 {
  line-height: 1.3;
  font-size: 1.1rem;
}
p {
  margin-block: 0 1em;
  margin-block-end: var(--regard-paragraph-spacing, 1em);
}
.intro {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 39rem;
}
.control-card {
  padding: 1.5rem;
  border: 1px solid var(--line);
  border-radius: 0.8rem;
  background: var(--surface);
  box-shadow: 0 8px 0 var(--accent);
  min-width: 0;
}
.control-card .eyebrow {
  margin-bottom: 1rem;
}
/* The same public styling hooks work on React and vanilla widgets. */
.demo-widget {
  --openregard-control-radius: 0.4rem;
  --openregard-control-padding: 0.75em;
  --openregard-gap: 0.6rem;
  --openregard-focus-color: var(--ink);
}
.demo-widget .openregard-label {
  flex: 1;
  font-size: 0.8rem;
  font-weight: 600;
}
.demo-widget .openregard-select {
  width: 100%;
}
.demo-widget .openregard-description {
  font-size: 0.78rem;
  margin-top: 0.8rem;
  color: var(--muted);
}
.section-head {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  margin-block: 1rem 1.5rem;
}
.section-head h2 {
  margin: 0;
}
.section-head p {
  font-size: 0.8rem;
  color: var(--muted);
  margin: 0;
}
.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
}
.card {
  border: 1px solid var(--line);
  border-radius: 0.7rem;
  padding: clamp(1.1rem, 3vw, 2rem);
  background: var(--surface);
  min-width: 0;
}
.card .eyebrow {
  margin-bottom: 1.4rem;
}
.dark {
  background: var(--panel-paper);
  color: var(--panel-ink);
  border-color: currentColor;
}
.dark p {
  color: inherit;
}
.large-number {
  font-family: Georgia, serif;
  font-size: 3.5rem;
  line-height: 1.2;
}
.tag {
  display: inline-block;
  border: 1px solid currentColor;
  border-radius: 2rem;
  padding: 0.2em 0.7em;
  font-size: 0.7rem;
}
label:not(.openregard) {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
}
input,
button {
  box-sizing: border-box;
  font: inherit;
  max-width: 100%;
  min-width: 0;
}
input {
  display: block;
  width: 100%;
  margin-top: 0.5em;
  padding: 0.75em;
  background: var(--paper);
  color: var(--ink);
  border: 1px solid var(--ink);
  border-radius: 0.35rem;
}
button {
  cursor: pointer;
  padding: 0.65em 0.9em;
  background: Canvas;
  color: CanvasText;
  border: 1px solid currentColor;
  border-radius: 0.35rem;
}
.sync-row {
  margin-block: 1.5rem 3rem;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 2rem;
  align-items: center;
  padding: 2rem;
  background: var(--accent);
  border: 1px solid var(--line);
  border-radius: 0.7rem;
}
.sync-row p {
  font-size: 0.85rem;
}
.doc-layout {
  display: grid;
  grid-template-columns: minmax(0, 12rem) minmax(0, 1fr);
  gap: 3rem;
}
.doc-index {
  border-top: 1px solid var(--line);
  padding-top: 1rem;
  font-size: 0.8rem;
}
.doc-index a {
  display: block;
  padding-block: 0.6em;
}
.doc-article {
  min-width: 0;
  max-width: 48rem;
}
.doc-article section {
  padding-block: 1rem 2rem;
}
.steps {
  padding-inline-start: 1.5rem;
}
.steps li {
  padding-inline-start: 0.4em;
  margin-block: 1em;
}
code {
  font-size: 0.88em;
  overflow-wrap: anywhere;
}
.code-note {
  padding: 1.5rem;
  background: var(--panel-paper);
  color: var(--panel-ink);
  border-radius: 0.5rem;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  line-height: 1.7;
}
.recipe-note {
  border-left: 3px solid currentColor;
  padding-inline-start: 1rem;
  font-size: 0.85rem;
}
footer {
  border-top: 1px solid var(--line);
  padding-block: 2rem;
  margin-top: 3rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--muted);
}
footer p {
  margin: 0;
  max-width: 40rem;
}
/* Spacing overrides also reach typography with authored heading/tracking values. */
:root:not([data-regard-profile="standard"])
  :is(h1, h2, h3, p, a, label, span, select, button, li) {
  line-height: var(--regard-line-height, 1.65);
  letter-spacing: var(--regard-letter-spacing, normal);
  word-spacing: var(--regard-word-spacing, normal);
}
@media (max-width: 850px) {
  .hero,
  .doc-layout {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .hero {
    padding-block: 2rem 3rem;
  }
  .doc-index {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1rem;
  }
}
@media (max-width: 600px) {
  .shell {
    width: calc(100% - 2rem);
  }
  .grid,
  .sync-row {
    grid-template-columns: 1fr;
  }
  .sync-row {
    padding: 1.25rem;
    gap: 1rem;
  }
  .masthead {
    padding-block: 1rem;
  }
}
@media (forced-colors: active) {
  .dark,
  .code-note {
    background: Canvas;
    color: CanvasText;
  }
  .control-card {
    box-shadow: none;
  }
}