css/css-overflow/overflow-outside-padding.html

<!DOCTYPE html>
<title>CSS Overflow and Transforms: css-overflow-3</title>
<link rel="author" href="mailto:atotic@google.com">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<link rel="help" href="https://www.w3.org/TR/css-overflow-3/#scrollable">
<meta name="assert" content="blocks wholly outside padding edges should not contribute to overflow">
<style>
.container {
  position: relative;
  display: inline-block;
  border: 5px solid rgba(0,0,0,0.5);
  border-width: 0px 0px 50px 80px;
  overflow: auto;
  width: 200px;
  height: 200px;
  background: gray;
}
.target {
  position: absolute;
  width: 1000px;
  height: 1000px;
  background: red;
}
.htb {
  writing-mode: horizontal-tb;
}
.vrl {
  writing-mode: vertical-rl;
}
.vlr {
  writing-mode: vertical-lr;
}
.rtl {
  direction: rtl;
}
</style>
<!--  -->
<div class="container htb">
  <div class="target" style="top: -1000px"></div>
  htb
</div>
<div class="container htb rtl">
  <div class="target" style="right: -1000px" ></div>
  htb rtl
</div>
<div class="container vrl">
  <div class="target" style="top: -1000px"></div>
  vrl
</div>
<div class="container vrl rtl">
  <div class="target" style="bottom: -1000px"></div>
  vrl rtl
</div>
<div class="container vlr">
  <div class="target" style="top: -1000px"></div>
  vlr
</div>
<div class="container vlr rtl">
  <div class="target" style="left: -1000px"></div>
  vlr rtl
</div>
<script>
test(() => {
  Array.from(document.querySelectorAll(".container")).forEach( el => {
    assert_equals(el.scrollWidth, 200);
  });
}, '#target did not trigger scroll overflow');
</script>