What is the best way to embed HTML code into a foreign website?

Question

I have developed a chart diagram which shows the temperature of a public bath. I want to host the HTML, CSS and JS code on my website.

I want that foreign websites can embed this diagram into their website with just one line of code.

I know these solutions:

1. Use

   <script src="..."></script>

2. Use

   <object type="text/html" data="..."></object>

3. Use

   <iframe src="..."></iframe>

These are the problems with each solution:

1. The CSS of the foreign website does make my diagram look bad. Also I have access to the cookies of the foreign website (but this would be acceptable).
2. The height of my diagram changes when the user interacts and I don't want a scrollbar to appear.
3. Same problems as object tag.

So what is the best (cleanest) way to do this?