When I do that nothing changes... Maybe the gap was ment to be there? Or that there is some invincible broken thing in the way.
Comment "padding-left: $gutter-size;" out with "/* ... */.
So it looks like this:
/* padding-left: $gutter-size; */
If that doesn't work comment out both rows.
I have done it like this
Saved correctly checked on another device and browser, still the same issue.
That's really strange. Actually the yellow part shouldn't be there anymore but it didn't disappear.
Sorry, I cannot help you anymore. Try to ask your question in "Shopify Design". Usually it is the better Shopify Discussion thread because more people are looking there.