Nothing appears on the screen without flex-grow

Tell us what’s happening:
why nothing appears without using flex-grow.

Your code so far

#box-container {
  display: flex;
  height: 500px;

#box-1 {
  background-color: dodgerblue;
  height: 200px;
  flex-grow: 1;

#box-2 {
  background-color: orangered;
  height: 200px;
  flex-grow: 2;

<div id="box-container">
<div id="box-1"></div>
<div id="box-2"></div>

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36.

Challenge: Use the flex-grow Property to Expand Items

Link to the challenge:

I copy pasted your code and it passes for me.
Might be some extention that blocks it try using incognito mode

Are you running a dark mode extension? If so, disable it. It will mess with a few of the lessons.