I also see something very relevant in the directions.
Replace your concatenated string in the querySelector with a template literal – be sure to keep the space between your targetId variable and .input-container.
The selector should be a descendant combinator. This means you need a space between the two selectors.
document.querySelector(theId theClass);
I’ve edited your code for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.
You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.