Initial code in embedded live editor not printable across various browsers and not exportable to PDF in Safari

Issue description:

When attempting to print the initial code present in the embedded live editor within the React.dev documentation, the code appears blank in Chrome, Firefox, and Safari. Additionally, the initial code is not exportable to PDF in Safari.

Having the ability to print or export the initial code as a PDF would allow users to read the documentation without a screen and try the code in their local environment using their preferred IDE, such as vscode, without the need for a second screen.

It's important to note that the Vue.js live editor supports printable initial codes.

Steps to reproduce:

1. Open the React.dev documentation with embedded live editor examples in Chrome, Firefox, or Safari.
2. Navigate to a page containing an embedded live editor with initial code.
3. Try to print the page or export it to PDF in Safari.

Expected behavior:

Initial code in the embedded live editor should be printable across different browsers and exportable to PDF in Safari.

Actual behavior:

1. Initial code in the embedded live editor is not printable in Chrome, Firefox, or Safari.
2. Initial code in the embedded live editor is not exportable to PDF in Safari.

Suggested solution:

Please consider adding support for printing and exporting the initial code in the embedded live editor within the documentation. This would make it more convenient for users who prefer to read the documentation without a screen and only use their IDE when trying out the code.

Additional information:

Comparatively, the Vue.js live editor supports printable initial codes in the mentioned browsers.

Thank you for looking into this issue. Please let me know if you need further information or clarification.

找出 React.dev 文件範例中使用的嵌入式即時編輯器，並先重現其在 Chrome、Firefox 和 Safari 中的列印功能，包括 Safari 中的 PDF 匯出。完成的標準是列印時可以看到初始程式碼，並且可以在 Safari 中將其匯出為 PDF；該 issue 未指定任何可用來引導實作的檔案或測試。