How to force parent div to expand by child div width/padding/margin/box?

body {
    background: gray;
}
div.page {
    color: white;
    background: black;
    margin: auto;
    padding: 1em;
    display:inline-block;
}
div.one {
    background-color: red;
    width: 10em;
    display:inline-block;
}
div.two {
    background-color: green;
    width: 40em;
    display:inline-block;
}

<div class="page">
  <div class="one">One</div>
  <div class="two">Two</div>
</div>