<!DOCTYPE html>
<html>
<link href="resources/flexbox.css" rel="stylesheet">
<style>
.flexbox {
    border: 2px solid orange;
}
.h3 {
    height: 300px;
}
.w3 {
    width: 300px;
}
.h4 {
    height: 400px;
}
.w4 {
    width: 400px;
}
.border-box, .flexbox > div {
    box-sizing: border-box;
    height: 100px;
    width: 100px;
    border: 2px solid lightblue;
    border-top-width: 4px;
    padding: 3px;
}
</style>
<script src="../../resources/check-layout.js"></script>
<body onload="checkLayout('.flexbox')">