Use display: flex to Position Two Boxes

This section uses alternating challenge styles to show how to use CSS to position elements in a flexible way. First, a challenge will explain theory, then a practical challenge using a simple tweet component will apply the flexbox concept. Placing the CSS property `display: flex;` on an element allows you to use other flex properties to build a responsive page. # --instructions-- Add the CSS property `display` to `#box-container` and set its value to `flex`.