Atom is the editor of choice for many, but one thing a lot of people don’t like is the white line that shows up when first installed. The culprit for this white line is the Wrap Guide Package. So you are left with two options:
1Disable the Package
The first option is to simply disable the package. This can be done in the editor through your preferences pages. You may be required to restart Atom in some cases.
2CSS Hack to Hide It
The next option, the one I tend to use as this is the original solution from the early days of Atom, is to add a small snippet of code to your stylesheet. This will hide the line for you. To edit your Stylesheet go to File > Stylesheet. Add the following code to the bottom and save the file.
The line should disappear when you save the file.