How to define column css in views? How to define column css in views?

I testing a theme. I tried edit the css from CSS class one-half to one-fourth. The layout changes successfully from half column to fourth column.

I wondered how the CSS define.

I looked into the views but can't find the css added (one-half)
Click here and check if it was added as a row class.

Else, look under Advanced 



If nothing is there, check your theme's templates folder. They probably created a template file (.tpl.php or .html.twig) for the view. 

Lastly, if still nothing, check inside your theme's folder for template.php or theme-name.theme