with default medium and litle screen size responsive breakpoints :
> i create 2 * 50% width column
= when screen is at the little screen responsive breakpoint, two horizontal columns come to 2 vertical columns. Fine.
i change the medium and little Resp.Brek.Point and set each colomn to be at 80% width at medium RBP and to be at 100% width at little RBP
> at medium screen size : columns are at 80% width but not horizontally centered like a margin (0 , auto) but are like no margin and stay on the left on the screen.
> at little screen size : colums are not at 100% as i set but like 50% and are not horizontally centered but are on the left of the screen.
What can i do to have my columns at 80% or 100% AND horizontally centerd ?
The reason why they are left aligned is most likely because your module was using the left alignment as well. What we can do is use media queries to set a different alignment for when the medium and small breakpoints are met. You can read more of media queries here. If, as a starting point, you would want us to help you with your concern, please reply back with the page URL you are having the problem with coupled with a temporary admin access to your site so we may check.
Couple your margin:0px auto; with a float: none; and that should do the trick. The thing is, if you use a custom width value for the column breakpoints, the float changes to left so putting two columns side by side would be possible. If left to default value, the float changes to none so the columns stack on top of each other. Hope this helps.
That’s actually because the Medium Breakpoint is geared towards tablets. Most tablets have wider resolution so they can afford to have 2 or more columns stay side by side. Whereas the Small Breakpoint, it is for mobile phones having a very narrow resolution where we have no option but to stack the columns on top of each other.