Whenever you are working with HTML code, it's always best to first copy your code to a blank web page or use jsfiddle.net. You can then test the code before embedding it, ensuring that it works and does what you want it to do. You can even test with multiple browsers for compatibility.
If the code isn't working on your test site it means that this code might not be suitable for our builder.
Elements that are added using external code can only be adjusted by editing the code itself and re-add it to the site.