Grid classes have been changed to account for a fourth set of classes,
meaning we now have XS, S, M, and L options. Specifically, we made the
following changes:
* Renames `.col-` to `.col-xs-`
* Adds `.col-md-` for devices 992px wide and up
* Remaps `.col-lg-` for devices 1200px wide and up
Alongside that, we've updated our media queries to better handle
advanced grid layouts:
* All column classes now kick in when they hit a `min-width`, undoing
the #9128 fix in
https://github.com/twbs/bootstrap/commit/db45a60cc86190a060f0baf0b3961cb
c690f3a65
* All column offsets, pushes, and pulls are scoped to an appropriate
range, meaning a `min-width` and `max-width` (thanks for the idea,
@eratzlaff)
We've also modified the widths of our grid containers for the small
device grid (now a max 720px instead of 728px) and large device grid
(now a max 1140px instead of 1170px) to avoid horizontal scrollbar
problems in Firefox (likely due to box-sizing, which is why we didn't
see it in 2.x).
Similarly, we've updated the responsive ultility classes to match the
new four media query approach of the grid system. That means we've:
* Added new `.visible-xs` and `.hidden-xs` classes
* Reassigns visible and hidden classes for small, medium, and large to
matching grid system media queries
* Updates docs examples to match grid system and account for fourth
utility range
-----
Fixes the following:
* #9135: fourth grid tier
* #9302: undoes previous range change for small grid system, so no need
to update any docs here
* #8755: consistent grid and responsive utilities schemas)
* #9195, #9216, and #9227: no more horizontal scrollbars
* Update docs to include table of grid levels and behaviors
* Change from .col-md to .col-sm to match existing size variables we use elsewhere
* Keep .col-lg as-is though for simplicity as we won't likely add a fourth level of the grid
* Combine responsive .container breakpoints with grid breakpoints in grid.less
* Other misc docs updates
- Removed mixins for generating grid classes
- Thus, we manually declare every grid class, from 1-11 (12th unit is
excluded as that's the same as no grid columns)
- No more need for `.col` base class (yay!)
- Negative indent the rows at tablets and above once again (ugh, still
working through this part)
- Add support for `.col-md` for tablet-specific grid columns
- Still need to figure out offsets, pushes, and pulls on other
devices—right now only available on desktop
* Add new grid mixins adapted from Preboot (http://github.com/mdo/preboot)
* Drop the @grid-row-width and @grid-column-width variables
* Add the @grid-float-breakpoint variable, as used in Preboot
* Add support for .push* and .pull* classes for column ordering manipulation
* Document all the things
