使容器在包装时缩小到适合子元素

.holder {
width: 500px;
background: lightgray;
display: flex;
flex-direction: row;
justify-content: space-between;
flex-wrap: nowrap;
}
.v2 {
width: 320px;
}
.child {
display: inline-block;
border: 1px solid black;
padding: 30px 0px;
text-align: center;
}

<div class="holder">
<div class="child">At a glance</div>
<div class="child">After coverage ends</div>
<div class="child">Forms &amp; documents</div>
</div>
<br>
<br>
<div class="holder v2">
<div class="child">At a glance</div>
<div class="child">After coverage ends</div>
<div class="child">Forms &amp; documents</div>
</div>
<br>
<br>
<div class="holder v2">
<div class="child">At a
<br>glance</div>
<div class="child">After coverage
<br>ends</div>
<div class="child">Forms &amp;
<br>documents</div>
</div>