picocss/scss/layout/_flexgrid.scss

// Grid | milligram.io | MIT License
// ––––––––––––––––––––––––––––––––––––––––––––––––––

// .flexgrid is main centered wrapper with a max width of 112.0rem (1120px)
.flexgrid {
  position: relative;
  width: 100%;
  max-width: 112.0rem;
  margin: 0 auto;
  padding: 0 2.0rem;
}
// Using flexbox for the grid, inspired by Philip Walton:
// http://philipwalton.github.io/solved-by-flexbox/demos/grids/
// By default each .col within a .row will evenly take up
// available width, and the height of each .col with take
// up the height of the tallest .col in the same .row
.row {
  display: flex;
  flex-direction: column;
  width: 100%;
  padding: 0;

  &.row-no-padding {
    padding: 0;

    & > .col {
      padding: 0;
    }
  }
  &.row-wrap {
    flex-wrap: wrap;
  }
  // Vertically Align columns
  // .row-* vertically aligns every .col in the .row
  &.row-top {
    align-items: flex-start;
  }
  &.row-bottom {
    align-items: flex-end;
  }
  &.row-center {
    align-items: center;
  }
  &.row-stretch {
    align-items: stretch;
  }
  &.row-baseline {
    align-items: baseline;
  }
  .col {
    display: block;
    // IE 11 required specifying the flex-basis otherwise it breaks mobile
    flex: 1 1 auto;
    width: 100%;
    max-width: 100%;
    margin-left: 0;

    // column Offsets
    &.col-os-10 {
      margin-left: 10%;
    }
    &.col-os-20 {
      margin-left: 20%;
    }
    &.col-os-25 {
      margin-left: 25%;
    }
    &.col-os-33 {
      margin-left: 33.3333%;
    }
    &.col-os-40 {
      margin-left: 40%;
    }
    &.col-os-50 {
      margin-left: 50%;
    }
    &.col-os-60 {
      margin-left: 60%;
    }
    &.col-os-66 {
      margin-left: 66.6666%;
    }
    &.col-os-75 {
      margin-left: 75%;
    }
    &.col-os-80 {
      margin-left: 80%;
    }
    &.col-os-90 {
      margin-left: 90%;
    }
    // Explicit column Percent Sizes
    // By default each grid column will evenly distribute
    // across the grid. However, you can specify individual
    // columns to take up a certain size of the available area
    &.col-10 {
      flex: 0 0 10%;
      max-width: 10%;
    }
    &.col-20 {
      flex: 0 0 20%;
      max-width: 20%;
    }
    &.col-25 {
      flex: 0 0 25%;
      max-width: 25%;
    }
    &.col-33 {
      flex: 0 0 33.3333%;
      max-width: 33.3333%;
    }
    &.col-40 {
      flex: 0 0 40%;
      max-width: 40%;
    }
    &.col-50 {
      flex: 0 0 50%;
      max-width: 50%;
    }
    &.col-60 {
      flex: 0 0 60%;
      max-width: 60%;
    }
    &.col-66 {
      flex: 0 0 66.6666%;
      max-width: 66.6666%;
    }
    &.col-75 {
      flex: 0 0 75%;
      max-width: 75%;
    }
    &.col-80 {
      flex: 0 0 80%;
      max-width: 80%;
    }
    &.col-90 {
      flex: 0 0 90%;
      max-width: 90%;
    }
    // .col-* vertically aligns an individual .col column
    .col-top {
      align-self: flex-start;
    }
    .col-bot {
      align-self: flex-end;
    }
    .col-cen {
      align-self: center;
    }
  }
}
// Larger than mobile screen
// Safari desktop has a bug using `rem`, but Safari mobile works
@media (min-width: 40.0rem) {
  .row {
    flex-direction: row;
    width: calc(100% + 2.0rem);
    margin-left: -1.0rem;

    .col {
      margin-bottom: inherit;
      padding: 0 1.0rem;
    }
  }
};