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.
https://i.sstatic.net/YvfDT.png
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.
https://i.sstatic.net/T1vaS.png
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.