I wonder why the 8 inline-block elements inside the flex div get squeezed and do not adhere to their setting (`width: 50px`).

```css
div {
  display: flex;
  justify-content: center;
  border: 1px solid red;
  width: 150px;
  overflow: auto;
}

a {
  display: inline-block;
  background: orange;
  width: 50px;
  height: 50px;
  margin: 10px;
}
```

```html
<div>
  <a>1</a><a>2</a><a>3</a><a>4</a><a>5</a><a>6</a><a>7</a><a>8</a>
</div>
```