ionic-framework/ionic/components/grid/grid.scss

/**
 * Grid
 * --------------------------------------------------
 * 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.
 */

$grid-padding-width:              10px !default;
$grid-responsive-sm-break:        567px !default;  // smaller than landscape phone
$grid-responsive-md-break:        767px !default;  // smaller than portrait tablet
$grid-responsive-lg-break:        1023px !default; // smaller than landscape tablet

@mixin responsive-grid-break($selector, $max-width) {
  @media (max-width: $max-width) {
    #{$selector} {
      flex-direction: column;

      .col, .col-10, .col-20, .col-25, .col-33, .col-34, .col-50, .col-66, .col-67, .col-75, .col-80, .col-90 {
        flex: 1;
        margin-bottom: ($grid-padding-width * 3) / 2;
        margin-left: 0;
        max-width: 100%;
        width: 100%;
      }
    }
  }
}


ion-row {
  display: flex;
  padding: ($grid-padding-width / 2);
  width: 100%;
  &[wrap] {
    flex-wrap: wrap;
  }
  &[flush] {
    padding: 0;
  }

  > .col {
    padding: 0;
  }

  &[top] {
    align-items: flex-start;
  }
  &[bottom] {
    align-items: flex-end;
  }

  &[center] {
    align-items: center;
  }
  &[stretch] {
    align-items: stretch;
  }
  &[baseline] {
    align-items: baseline;
  }
}

ion-row + ion-row {
  margin-top: ($grid-padding-width / 2) * -1;
  padding-top: 0;
}

ion-col {
  flex: 1;
  display: block;
  padding: ($grid-padding-width / 2);
  width: 100%;

  &[top] {
    align-self: flex-start;
  }
  &[bottom] {
    align-self: flex-end;
  }
  &[center] {
    align-self: center;
  }
}


/* Vertically Align Columns */
/* .row-* vertically aligns every .col in the .row */

/* .col-* vertically aligns an individual .col */

/* Column Offsets */
.col-offset-10 {
  margin-left: 10%;
}
.col-offset-20 {
  margin-left: 20%;
}
.col-offset-25 {
  margin-left: 25%;
}
.col-offset-33, .col-offset-34 {
  margin-left: 33.3333%;
}
.col-offset-50 {
  margin-left: 50%;
}
.col-offset-66, .col-offset-67 {
  margin-left: 66.6666%;
}
.col-offset-75 {
  margin-left: 75%;
}
.col-offset-80 {
  margin-left: 80%;
}
.col-offset-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, .col-34 {
  flex: 0, 0, 33.3333%;
  max-width: 33.3333%;
}
.col-50 {
  flex: 0, 0, 50%;
  max-width: 50%;
}
.col-66, .col-67 {
  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%;
}


/* Responsive Grid Classes */
/* Adding a class of responsive-X to a row */
/* will trigger the flex-direction to */
/* change to column and add some margin */
/* to any columns in the row for clearity */

@include responsive-grid-break('.responsive-sm', $grid-responsive-sm-break);
@include responsive-grid-break('.responsive-md', $grid-responsive-md-break);
@include responsive-grid-break('.responsive-lg', $grid-responsive-lg-break);