Umm... using universal selector is one of the most complex things of CSS, so it is very difficult to comment on this.

It looks like there is a dilemma, judging from the difference of the selectors between the 60 classes and the.no-gutters. At least, I agree with the performance problem of the.no-gutters selector. If we take consistency seriously, the changes will be right. There is no problem with the breaking change.

Umm... using universal selector is one of the most complex things of CSS, so it is very difficult to comment on this.

What exactly do you mean withcomplex?

Also just added an edit for.form-row, the same technique from.no-gutters was used there.

Sorry for late reply.

What exactly do you mean with complex?

It means that it's difficult to understand and use them effect. Universal selectors have the power to easily break other styles.

For example, expects the following case? (Aside from whether the such usage is good or bad):
https://codepen.io/anon/pen/oOwYQO

From the docs:

In a grid layout, content must be placed within columns and only columns may be immediate children of rows.

For example, expects the following case? (Aside from whether the such usage is good or bad): codepen.io/anon/pen/oOwYQO

Aside from the fact that's not a good idea, the theming can easily be overridden with a class (even without!important because* has no effect on specificity:https://codepen.io/MartijnCuppens/pen/yroKYz

Haven't spent nearly enough time in Bootstrap work, but what about something akin to Primer? For example:https://styleguide.github.com/primer/objects/grid/#flexbox-grids. Primer has column classes that only setwidth in%s and then utilities are used for creating the flexbox behaviors you want.

@mdo, this PR only covers the way paddings are set. We could also change the grid so that the.col-* classes can be used without the need of a.row parent like Primer. This would also provide a solution for#21943.

Shall I extend the scope of this PR and also add that change here?

Perhaps! What are your thoughts on going that direction? It'd be one of the bigger changes to arguably one of our biggest and most well known features.

I've experimented with widths instead of flex-basis and it looks like we can drop the max-widths, gonna check some browsers and test some edge cases, but it looks promising. I'll tweak this PR further later this week!

Would also close#26512.

Updated the PR and introduced a second grid. The second grid mimics the behaviour of the block gutters ofdisplay: grid. Documentation is still lacking, we'll probably need to have a look at how we combine this PR with#28450.

@MartijnCuppens Looking at this new secondary grid, maybe we just usedisplay: grid? Support appears close enoughhttps://caniuse.com/#feat=css-grid.

IE doesn't support auto placement or gutters. Can't do this yet.

Will update this PR soon. Not sure if we should go for the second grid (.grid) or if we should introduce gutter classes in x and y direction. What do you think,@mdo?

Ah, wasn't aware of those shortcomings. Vertical margins for gutters have been asked in the past, so if that saves on a few selectors (adding.grid to.row), I'm in favor.

might anything be in the works for the negative margins on.row? I think those exist to offset grids being placed in a container, but the rows/cols otherwise work fine w/o container

@twbs/css-review I have read through all the changes! Please see#28517 (comment)

@MartijnCuppens,@XhmikosR Can we merge this? Are there any remaining tasks?

This is quite a change and personally I haven't reviewed it. I'd say wait until we get an approval from@mdo before moving forward with this.

We might consider a switch to CSS grid now that we've descided to drop IE11 support. Not sure how to provide a solution forcol-auto andcol though.

Anyway, merging this would be a good base to build upon later on.

🙌🏻👏🏻🎉

We're all looking forward to seeing IE11 disappear over the horizon. I'm repeating myself but I love the flexbox utility classes, and wish we had the same utilities available for CSS Grid. We're open to an asbstraction of CSS Grid but not sure we'd implement another approach to grids, even as an interim step. Our new design system is heavily invested in web standards, semantic markup and accessibility, and we have application developers already creating PoCs with CSS Grid. Appreciate everyone's work on making BS better.