How do I get the white background to fit with the black border line ?

[PROBERT68]

See the picture as I am trying to get the white backgound to fit with the black border line 

I try to find for that but I was not able to do it.. Is anyone having the same problem as i have ?

Using ArcGIS Pro 2.4.1

[PROBERT68]

Never mind I got it fixed.