When deploying a project to Heroku, backgraunds are not loaded, what could be the reason for this?

Question

css

After I posted the project on Heroku, backgrounds are not displayed on it, namely those backgrounds that use different images. What could be the problem, who faced this?

Answer 1

Set the width of the child elements. For example, 30%
Result
PS Better yet, use Flexbox ( Result )
PS For the parent, you have a width of 300px. Somehow not enough.