Использование API для отображения документа в полноэкранном режиме

<div id="container">
  <p class="in-pip-message">
    Video player is currently in the separate Picture-in-Picture window.
  </p>
  <div id="player">
    <video
      src="assets/bigbuckbunny.mp4"
      id="video"
      controls
      width="320"></video>

    <div id="credits">
      <a href="https://peach.blender.org/download/" target="_blank">
        Video by Blender </a
      >;
      <a href="https://peach.blender.org/about/" target="_blank">
        licensed CC-BY 3.0
      </a>
    </div>

    <div id="control-bar">
      <p class="no-picture-in-picture">
        Document Picture-in-Picture API not available
      </p>

      <p></p>
    </div>
  </div>
</div>

if ("documentPictureInPicture" in window) {
  document.querySelector(".no-picture-in-picture").remove();

  const togglePipButton = document.createElement("button");
  togglePipButton.textContent = "Toggle Picture-in-Picture";
  togglePipButton.addEventListener("click", togglePictureInPicture, false);

  document.getElementById("control-bar").appendChild(togglePipButton);
}

async function togglePictureInPicture() {
  // Early return if there's already a Picture-in-Picture window open
  if (window.documentPictureInPicture.window) {
    return;
  }

  // Open a Picture-in-Picture window.
  const pipWindow = await window.documentPictureInPicture.requestWindow({
    width: videoPlayer.clientWidth,
    height: videoPlayer.clientHeight,
  });

  // ...

  // Move the player to the Picture-in-Picture window.
  pipWindow.document.body.append(videoPlayer);

  // Display a message to say it has been moved
  inPipMessage.style.display = "block";
}

// ...

// Copy style sheets over from the initial document
// so that the player looks the same.
[...document.styleSheets].forEach((styleSheet) => {
  try {
    const cssRules = [...styleSheet.cssRules]
      .map((rule) => rule.cssText)
      .join("");
    const style = document.createElement("style");

    style.textContent = cssRules;
    pipWindow.document.head.appendChild(style);
  } catch (e) {
    const link = document.createElement("link");

    link.rel = "stylesheet";
    link.type = styleSheet.type;
    link.media = styleSheet.media;
    link.href = styleSheet.href;
    pipWindow.document.head.appendChild(link);
  }
});

// ...

@media (display-mode: picture-in-picture) {
  body {
    background: red;
  }
}

@media (display-mode: picture-in-picture) and (prefers-color-scheme: light) {
  body {
    background: antiquewhite;
  }
}

@media (display-mode: picture-in-picture) and (prefers-color-scheme: dark) {
  body {
    background: #333;
  }

  a {
    color: antiquewhite;
  }
}

inPipMessage.style.display = "none";
playerContainer.append(videoPlayer);
window.documentPictureInPicture.window.close();

pipWindow.addEventListener("pagehide", (event) => {
  inPipMessage.style.display = "none";
  playerContainer.append(videoPlayer);
});

documentPictureInPicture.addEventListener("enter", (event) => {
  const pipWindow = event.window;
  console.log("Video player has entered the pip window");

  const pipMuteButton = pipWindow.document.createElement("button");
  pipMuteButton.textContent = "Mute";
  pipMuteButton.addEventListener("click", () => {
    const pipVideo = pipWindow.document.querySelector("#video");
    if (!pipVideo.muted) {
      pipVideo.muted = true;
      pipMuteButton.textContent = "Unmute";
    } else {
      pipVideo.muted = false;
      pipMuteButton.textContent = "Mute";
    }
  });

  pipWindow.document.body.append(pipMuteButton);
});

const pipWindow = window.documentPictureInPicture.window;
if (pipWindow) {
  // Mute video playing in the Picture-in-Picture window.
  const pipVideo = pipWindow.document.querySelector("#video");
  pipVideo.muted = true;
}