Special-Character Safe Web Form

I need a small web form that accepts user input containing Unicode symbols, Mathematical symbols, and Accented letters without breaking, stripping characters, or causing encoding errors. The form’s task is simple—collect the data, show it back to the user in a confirmation message, and save it safely to the backend in the exact form it was entered.

While I did not lock the brief to a single form style, it will likely resemble a concise contact or registration form (name, email, message/notes field). Whichever structure we settle on, every field must be:

• Encoded so that all three character categories display correctly in every modern browser.
• Sanitised to prevent XSS or injection attacks while still preserving the original characters.
• Logged to the database or flat-file storage with no loss of data fidelity.

Feel free to choose the tech stack you are most comfortable with—PHP, Node, Python, or a lightweight framework—as long as the final result is portable and straightforward to deploy on a standard Linux host. Provide clear setup instructions and a quick demo page so I can verify end-to-end behaviour.