flexbox container demo

HTML

<div class="container-flex">
    <div class="flex-item">Flex1</div>
    <div class="flex-item">Flex1</div>
</div>

CSS

.container-flex{
    display:flex;
    background-color:silver;
    flex-direction:column;
    height:200px;
}

.flex-item{
    width: 100px;
    height: 100px;
    margin: 5px;
    background-color: pink;
}