JSFiddle - React, Tailwind, and code Playground

HTML

<div class="grid__row grid__row--md">
  <div class="grid__item-flex">
    <div class="grid__row grid__row-md parent">
      <div class="grid__item-flex checkinput"><input type="checkbox"><label>Test Column 1</label></div>
        <div class="grid__row grid__row--md">
          <div class="grid__item-flex">
            <div class="grid__row grid__row-md parent">
              <div class="grid__item-flex checkinput"><input type="checkbox"><label>Column Item</label></div>
            </div>
          </div>
        </div>
        <div class="grid__row grid__row--md">
          <div class="grid__item-flex ">
            <div class="grid__row grid__row-md parent">
              <div class="grid__item-flex checkinput"><input type="checkbox"><label>Column Item</label></div>
            </div>
          </div>
        </div>
        <div class="grid__row grid__row--md">
          <div class="grid__item-flex ">
            <div class="grid__row grid__row-md parent">
              <div class="grid__item-flex checkinput"><input type="checkbox">
                <label>Column Item</label>
              </div>
            </div>
          </div>
        </div>
    </div>
  </div>
  <div class="grid__item-flex">
    <div class="grid__row grid__row-md parent">
      <div class="grid__item-flex checkinput"><input type="checkbox"><label>Test Column 2</label></div>
        <div class="grid__row grid__row--md">
          <div class="grid__item-flex">
            <div class="grid__row grid__row-md child parent">
              <div class="grid__item-flex checkinput"><input type="checkbox"><label>Column Item</label>
              </div>
            </div>
          </div>
        </div>
        <div class="grid__row grid__row--md">
          <div class="grid__item-flex ">
            <div class="grid__row grid__row-md parent">
              <div class="grid__item-flex checkinput"><input type="checkbox"><label>Column Item</label>
              </div>
            </div>
          </div>
...

CSS

/*********************************************/
/**** SUSPECT FLEXBOX BREAKING CODE IN IE ****/
/*********************************************/

.grid__row {
    display: flex;
    flex-direction: row;
}
.grid__row .grid__row {
    margin: 0px 0px 0px 15px;
}
.grid__row-overflow {
  flex: 1 1;
}
.grid__row .order-group {
    display: flex;
    flex-direction: row;
    flex-grow: 1;
}
.grid__item {
    flex: 1;
    padding: 0px;
}
.grid__item-flex {
    display: flex;
    flex: 0 1 auto;
    padding-top: 1px;
}
.grid__item-flex:only-child {
    flex: 1 1 auto;
}
.parent {
    flex-direction: column;
    display: flex;
    margin-bottom: 20px;
}
.order-group {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
}
/*********************************************/
/*********************************************/
/*********************************************/