Remove the line under headings - Custom CSS

I installed the Custom CSS “Claire de Lune” by Jamie Brynes, and it comes with lines under the headings, which I do not want it to be present. I am a noob in CSS and I am finding it difficult to locate the code which results in the line under the headings.

It would be great if anyone could point me to the code which could contribute to the line.

Link to the Custom CSS GitHub: Claire de Lune

Update: I found the code and removed the line.

It looked like this (If this might help someone)

border-bottom: 10px solid #444a73;

Thanks, I was getting “concerned” not having a clear way of knowing what was added by a custom theme or my own efforts, I am just using “<u>Underline me</u>” specifically and with some reservation since most links are underlined.

Only issue is hunting that line of code again as the theme is updated.