tachyons/src/_border-radius.css

@custom-media --breakpoint-not-small screen and (min-width: 48em);
@custom-media --breakpoint-medium screen and (min-width: 48em) and (max-width: 64em);
@custom-media --breakpoint-large screen and (min-width: 64em);

/*

   BORDER RADIUS

   Base:
     br   = border-radius

   Modifiers:
     0    = 0/none
     1    = 1st step in scale
     2    = 2nd step in scale
     3    = 3rd step in scale
     4    = 4th step in scale
     -100 = 100%


   Media Query Extensions:
     -ns = not-small
     -m  = medium
     -l  = large

*/

  .br0 {        border-radius: 0; }
  .br1 {        border-radius: .125rem; }
  .br2 {        border-radius: .25rem; }
  .br3 {        border-radius: .5rem; }
  .br4 {        border-radius: 1rem; }
  .br-100 {     border-radius: 100%; }
  .br--bottom {
      border-top-left-radius: 0;
      border-top-right-radius: 0;
  }
  .br--top {
      border-bottom-left-radius: 0;
      border-bottom-right-radius: 0;
  }

@media (--breakpoint-not-small) {
  .br0-ns {     border-radius: 0; }
  .br1-ns {     border-radius: .125rem; }
  .br2-ns {     border-radius: .25rem; }
  .br3-ns {     border-radius: .5rem; }
  .br4-ns {     border-radius: 1rem; }
  .br-100-ns {  border-radius: 100%; }
  .br--bottom-ns {
      border-top-left-radius: 0;
      border-top-right-radius: 0;
  }
  .br--top-ns {
      border-bottom-left-radius: 0;
      border-bottom-right-radius: 0;
  }
}

@media (--breakpoint-medium) {
  .br0-m {     border-radius: 0; }
  .br1-m {     border-radius: .125rem; }
  .br2-m {     border-radius: .25rem; }
  .br3-m {     border-radius: .5rem; }
  .br4-m {     border-radius: 1rem; }
  .br-100-m {  border-radius: 100%; }
  .br--bottom-m {
      border-top-left-radius: 0;
      border-top-right-radius: 0;
  }
  .br--top-m {
      border-bottom-left-radius: 0;
      border-bottom-right-radius: 0;
  }
}

@media (--breakpoint-large) {
  .br0-l {     border-radius: 0; }
  .br1-l {     border-radius: .125rem; }
  .br2-l {     border-radius: .25rem; }
  .br3-l {     border-radius: .5rem; }
  .br4-l {     border-radius: 1rem; }
  .br-100-l {  border-radius: 100%; }
  .br--bottom-l {
      border-radius-top-left: 0;
      border-radius-top-right: 0;
  }
  .br--top-l {
      border-bottom-left-radius: 0;
      border-bottom-right-radius: 0;
  }
}