Two stylesheets acting on one element

When in doubt, !important it out!

In the child, change it to max-width:769px !important;. That will force the page to be rendered with that style.

I have a feeling the parent theme is using @import to get custom.css (although I cant verify that). That could be screwing with things.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)