The 1140 grid, flexbox.

grid.css

@media only screen and (min-width: 600px) {

  .grid {
    display: flex;
  }

  .onecol    { width: 5.801104972%;  }       /* 4.85%;  } /* grid_1  */
  .twocol    { width: 14.364640883%; }       /* 13.45%; } /* grid_2  */
  .threecol  { width: 22.928176794%; }       /* 22.05%; } /* grid_3  */
  .fourcol   { width: 31.491712705%; }       /* 30.75%; } /* grid_4  */
  .fivecol   { width: 40.055248616%; }       /* 39.45%; } /* grid_5  */
  .sixcol    { width: 48.618784527%; }       /* 48%;    } /* grid_6  */
  .sevencol  { width: 57.182320438000005%; } /* 56.75%; } /* grid_7  */
  .eightcol  { width: 65.74585634900001%; }  /* 65.4%;  } /* grid_8  */
  .ninecol   { width: 74.30939226%; }        /* 74.05%; } /* grid_9  */
  .tencol    { width: 82.87292817100001%; }  /* 82.7%;  } /* grid_10 */
  .elevencol { width: 91.436464082%; }       /* 91.35%; } /* grid_11 */
  .twelvecol { width: 99.999999993%; }       /* 100%;   } /* grid_12 */

  /* layout & column defaults */
  .onecol, .twocol, .threecol, .fourcol, .fivecol, .sixcol, .sevencol, .eightcol, .ninecol, .tencol, .elevencol, .twelvecol {
    position: relative;
    padding-left: 2.762430939%;
  }

  .first {
    padding-left: 0;
  }

}