<!DOCTYPE html>
<title>position:sticky elements should work correctly with grid layout</title>
<link rel="match" href="position-sticky-grid-ref.html" />
<link rel="help" href="https://www.w3.org/TR/css-position-3/#sticky-pos" />
<meta name="assert" content="This test checks that position:sticky elements interoperate correctly with grid" />

<style>
.scroller {
  position: relative;
  overflow-x: scroll;
  overflow-y: hidden;
  width: 300px;
  height: 100px;
  margin-bottom: 15px;
}

.grid-container {
  display: grid;
  grid-template-columns: 25% 25% 25% 25%;
  grid-template-rows: 100%;
  width: 400px;
  height: 90px;
}

.sticky {
  position: sticky;
  left: 50px;
}

.green {
  background-color: green;
}

.grid-item {
  width: 100%;
  height: 100%;
  grid-row: 1;
}

.indicator {
  position: absolute;
  background-color: red;
  width: 100px;
  height: 90px;
}

.padding {
  height: 1px;
  width: 700px;
}

</style>

<script>
window.addEventListener('load', function() {
  document.getElementById('scroller1').scrollLeft = 0;
  document.getElementById('scroller2').scrollLeft = 150;
  document.getElementById('scroller3').scrollLeft = 300;
});
</script>

<div id="scroller1" class="scroller">
  <div class="grid-container">
    <div class="indicator" style="left: 100px;"></div>
    <div class="grid-item" style="grid-column: 1;"></div>
    <div class="sticky green grid-item" style="grid-column: 2;"></div>
    <div class="green grid-item" style="grid-column: 3;"></div>
  </div>
  <div class="padding"></div>
</div>

<div id="scroller2" class="scroller">
  <div class="grid-container">
    <div class="indicator" style="left: 200px;"></div>
    <div class="grid-item" style="grid-column: 1;"></div>
    <div class="sticky green grid-item" style="grid-column: 2;"></div>
    <div class="green grid-item" style="grid-column: 3;"></div>
  </div>
  <div class="padding"></div>
</div>

<div id="scroller3" class="scroller">
  <div class="grid-container">
    <div class="indicator" style="left: 300px;"></div>
    <div class="grid-item" style="grid-column: 1;"></div>
    <div class="sticky green grid-item" style="grid-column: 2;"></div>
    <div class="green grid-item" style="grid-column: 3;"></div>
  </div>
  <div class="padding"></div>
</div>

<p>You should see three green boxes of varying size above. There should be no red.</p>