I've been working on customizing the Tabulator header filter to have a more "flattened" style, as requested by my boss. In my CSS, I added the code ...input:focus{border:1px solid #1bb394} to change the input border to 1px green. While this change takes effect, I'm encountering an issue where on focus, there is an additional black border inside the green one that I can't pinpoint the origin of.
The extra black border appears to be about 2px solid with a border-radius of approximately 3. Despite searching through the stylesheets, I couldn't locate the specific entry responsible for this. Interestingly, I noticed that the Tabulator demo page also displays this issue, indicating that the problematic style must be defined within Tabulator's codebase.
Considering it might not be directly associated with the input element itself, I'm seeking advice on where to look in order to correct or remove this unwanted black border.