Prompt

Make a card that shows how many days are left until the summer holidays. It has to be a single HTML file that opens in a browser with nothing to install and no other files. Put the CSS and JavaScript inside it.

The day is 2026-12-25. Show the number of days left very large in the middle of the screen, with what I am waiting for written above it and the date written small underneath.

Let me change the date and the name on the screen, and keep whatever I set after closing and reopening the browser.

If the day has passed, change it to "days since". If it is today, show "it is today". All three cases have to read naturally.

Make it look right on a phone: let the number grow with the width of the screen. Do not use image files or any external address.

When you are done, go through it as if you had set the date to yesterday, today, and tomorrow. Check the wording is right in all three cases, fix it, and give me only the final version.