Untitled

<!DOCTYPE html>
<html>
<head>
  <script src=”prefixfree.min.js” type="text/javascript"></script>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
<style id="jsbin-css">
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;

}
body{
    background: #e9e9e9;
}

.contenedor{
    width: 500px;
    height: 200px;
    background: #fff;
    padding: 10px;
    border: 10px solid #2c3e50;
    margin: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
  /*  align-content: flex-start; /// */
    flex-wrap: no-wrap;
    flex-direction: row;


}

.elemento {
    color: #fff;
    margin: 5px;
/*    width: 50px; */
    flex-basis: 150px;
    height: 50px;
    background: #e67e22;
    text-align: center;

}
</style>
</head>
<body>
  <div class="contenedor">
    <div class="elemento elemento1">1</div>
    <div class="elemento elemento2">2</div>
    <div class="elemento elemento3">3</div>
    <div class="elemento elemento4">4</div>
  </div>


<script id="jsbin-source-css" type="text/css">* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;

}
body{
    background: #e9e9e9;
}

.contenedor{
    width: 500px;
    height: 200px;
    background: #fff;
    padding: 10px;
    border: 10px solid #2c3e50;
    margin: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
  /*  align-content: flex-start; /// */
    flex-wrap: no-wrap;
    flex-direction: row;


}

.elemento {
    color: #fff;
    margin: 5px;
/*    width: 50px; */
    flex-basis: 150px;
    height: 50px;
    background: #e67e22;
    text-align: center;

}

</script>
</body>
</html>