Edit in JSFiddle

<h3>
order
</h3>
<div class="wrapper">
  <div class="box a">A</div>
  <div class="box b">B</div>
  <div class="box c">C</div>
  <div class="box d">D</div>
  <div class="box e">E</div>
  <div class="box f">F</div>
</div>

body {
  padding: 20px;
  font-family: Helvetica;
}

.wrapper {
  display: flex;
  background-color:#eee;
  margin-bottom:10px;
  border:1px solid #CCC;
}

.a { order: 2;}
.c { order: 1;}
.e { order: 1;}
.f { order: 1;}

.flex-start {
  justify-content:flex-start;
}

.flex-end {
  justify-content:flex-end;
}

.center {
  justify-content:center;
}

.space-between {
  justify-content:space-between;
}

.space-around {
  justify-content:space-around;
}

.box {
  background-color: #20262e;
  color: #fff;
  border-radius: 3px;
  padding: 20px;
  margin:10px;
  font-size: 14px;
  width:fit-content;
}