I set all element's border-radius to "0" like this:
* {
border-radius: 0 !important;
}
As I'm sure I don't want to overwrite this later I just use !important.
If you are not compiling your less files just do:
* {
-webkit-border-radius: 0 !important;
-moz-border-radius: 0 !important;
border-radius: 0 !important;
}
In bootstrap 3 if you are compiling it you can now set radius in the variables.less file:
@border-radius-base: 0px;
@border-radius-large: 0px;
@border-radius-small: 0px;
In bootstrap 4 if you are compiling it you can disable radius alltogether in the _custom.scss
file:
$enable-rounded: false;