css/css-contain/contain-inline-size-bfc-floats-001.html

<!doctype html>
<title>CSS Containment Test: inline-size of fit-content bfc constrained by floats, affected by height via its contents</title>
<link rel="help" href="https://drafts.csswg.org/css-contain-3/#containment-inline-size">
<link rel="match" href="contain-inline-size-bfc-floats-001-ref.html">
<style>
  .float { float: left; background-color: blue; }
  .right { float: right; }

  #outer { width: 400px; }
  #float1 { width: 200px; height: 100px; }
  #float2 { width: 250px; height: 100px; }
  #float3 { width: 300px; height: 100px; }

  #contain {
    contain: inline-size;
    display: flow-root;
    width: fit-content;
    line-height: 1em;
  }
  #filler { height: 150px; }
  #orange {
    display: inline-block;
    width: 200px;
    height: 20px;
    background: orange;
    vertical-align: top;
  }
</style>
<p>You should see a wide orange rectangle to the left of the third float, overlapping the float.</p>
<div id="outer">
  <div id="float1" class="float right"></div>
  <div id="float2" class="float left"></div>
  <div id="float3" class="float right"></div>
  <div id="contain">
    <span id="orange"></span>
    <div id="filler"></div>
  </div>
</div>