Hello,

First of all, thanks for this interesting and very useful tool. It will be really helpful for newcomers and those who want to refresh his knowledge of modern C++ standards.

Just a suggestion of a tiny UX improvement: it'd be nice to synchronize code output in the web page when scrolling. Right now you have to scroll both panels manually to compare output side by side.

Optionally, may be something similar to diff view with slightly colored lines (of course, a full diff highlighting, like in github, isn't needed).