<!DOCTYPE html>
<title>Tests the fallback value in anchor queries</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-1/#anchor-pos">
<link rel="help" href="https://drafts.csswg.org/css-anchor-1/#anchor-size">
<link rel="author" href="mailto:xiaochengh@chromium.org">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/check-layout-th.js"></script>
<script src="support/test-common.js"></script>
<style>
#container {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  width: 300px;
}

.flex-item {
  width: 100px;
  height: 50px;
  flex: auto;
}

#a1 {
  anchor-name: --a1;
  background: orange;
}
#a2 {
  anchor-name: --a2;
  background: purple;
}

.target {
  position: absolute;
}
</style>

<body onload="checkLayoutForAnchorPos('.target')">
  <div id="container">
    <div class="flex-item" id="a1"></div>
    <div class="flex-item"></div>
    <div class="flex-item"></div>
    <div class="flex-item"></div>
    <div class="flex-item"></div>
    <div class="flex-item"></div>
    <div class="flex-item"></div>
    <div class="flex-item"></div>
    <div class="flex-item" id="a2"></div>

    <!-- Fallback due to no valid anchor -->
    <div class="target" style="left: anchor(--inexist-anchor left, 50px)" data-offset-x="50"></div>
    <div class="target" style="width: anchor-size(--inexist-anchor width, 50px)" data-expected-width="50"></div>

    <!-- Fallback due to wrong axis for anchor() -->
    <div class="target" style="left: anchor(--a1 top, 50px)" data-offset-x="50"></div>
    <div class="target" style="left: anchor(--a1 bottom, 50px)" data-offset-x="50"></div>
    <div class="target" style="top: anchor(--a1 left, 50px)" data-offset-y="50"></div>
    <div class="target" style="top: anchor(--a1 right, 50px)" data-offset-y="50"></div>

    <!-- More complicated fallback values -->
    <div class="target" style="left: anchor(--inexist-anchor left, 50%)" data-offset-x="150"></div>
    <div class="target" style="left: anchor(--inexist-anchor left, calc(20% + 20px))" data-offset-x="80"></div>
    <div class="target" style="top: anchor(--a1 left, anchor(--a2 top))" data-offset-y="100"></div>
    <div class="target" style="top: anchor(--a1 left, calc((anchor(--a1 bottom) + anchor(--a2 top)) / 2))" data-offset-y="75"></div>
    <div class="target" style="width: anchor-size(--inexist-anchor width, 50%)" data-expected-width="150"></div>
    <div class="target" style="width: anchor-size(--inexist-anchor width, calc(20% + 20px))" data-expected-width="80"></div>
    <div class="target" style="height: anchor-size(--inexist-anchor height, anchor-size(--a1 width))" data-expected-height="100"></div>
    <div class="target" style="height: anchor-size(--inexist-anchor height, calc((anchor-size(--a1 width) + anchor-size(--a2 height)) / 2))" data-expected-height="75"></div>
  </div>
</body>
