Each column has horizontal padding called a gutter for controlling the space between them.
Bootstrap add gutter between columns.
That padding is offset in rows for the first and last column via negative margin on rows.
Gutters let us add padding between columns.
Bootstrap 4 now has spacing utilities that make adding or substracting the space gutter between columns easier.
Every column have a padding of 15 px on both sides.
Predefined classes like row and col sm 4 are available for quickly making grid layouts.
Rows are wrappers for columns.
Use container for a responsive pixel width or container fluid for width.
100 across all viewport and device sizes.
Div class container px 4 div class row gx 5 div class col div class p 3 border column padding div div div class col div class p 3 border column padding div div div div.
Content should be placed within columns and only columns may be immediate children of rows.
This padding is then counteracted on the rows with negative margins.
Add it to the row div like this.
For example we can write.
You also must adjust the negative margin so that spacing around the outer columns is not affected.
We can use it to space and align content.
Div class row div class text center col md 6 div class mr 2 widget 1 div div div class text center col md 6 div class ml 2 widget 2 div div div.
Every column get a width of 940 12.
Which makes a gutter between of 30 px.
I will name this class gutter border.
Extra css isn t necessary.
To add a border in the gutter we will change the columns to use margin and padding and also add a left border.
Columns create gutters gaps between column content via padding.
The resulting grid gutter width 2 on both sides of the grid will be hide with a negative margin of 15px.
In the case of the sm grid your container class will 970px 940px grid gutter width.
We will define a new class that when added to the container div row will override the default style for the columns.