I'm doing this table like layout with divs and flex as some styling got more complicated I had to leave "real" <table> behind and do it like this. With that out the way. 
One of my main issues here is that table-card, table-card__head or table-card__body does not become full width to wrap the rows. I'm my example I made one of the rows to have more cells. At this point to be perfectly honest, I have no idea on why this is. I would highly appreciate pointers.
I'll drop a fiddle as well just in case
* {
  box-sizing: border-box;
}
/* plage specific */
.table-card__cell-width .table-card__head-cell,
.table-card__cell-width .table-card__cell {
  width: 11.25rem;
}
/* shared styles */
.table-card {
  position: relative;
}
.table-card__head {
  position: -webkit-sticky;
  position: sticky;
  top: 0;
  z-index: 2;
}
.table-card__head-row {
  display: flex;
  flex-direction: row;
  flex-wrap: nowrap;
  background-color: coral;
}
.table-card__head-cell {
  border-right: 1px solid aqua;
  height: 2rem;
  line-height: 2rem;
  text-align: center;
}
.table-card__body {
  flex: 1 0 100%;
}
.table-card__row {
  flex-shrink: 0;
  display: flex;
  flex-wrap: nowrap;
  background-color: white;
  border-bottom: 1px solid #cccccc;
}
.table-card__row:nth-child(odd) {
  background-color: #ededed;
}
.table-card__cell {
  display: flex;
  flex-shrink: 0;
  justify-content: center;
  align-items: center;
  height: 4rem;
  border-right: 1px solid #cccccc;
}
<div class="table-card">
  <div class="table-card__head table-card__cell-width">
    <div class="table-card__head-row">
      <div class="table-card__head-cell">Head 1</div>
      <div class="table-card__head-cell">Head 2</div>
      <div class="table-card__head-cell">Head 3</div>
      <div class="table-card__head-cell">Head 4</div>
    </div>
  </div>
  <div class="table-card__body table-card__cell-width">
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
    <div class="table-card__row">
      <div class="table-card__cell">Value 1</div>
      <div class="table-card__cell">Value 2</div>
      <div class="table-card__cell">Value 3</div>
      <div class="table-card__cell">Value 4</div>
    </div>
  </div>
</div>