Files
rust_browser/tests/goldens/fixtures/218-z-index-zero-step6.html
Zachary D. Rowitsch 53dd6646b2 Implement stacking contexts and z-index per CSS 2.1 §9.9.1 / Appendix E
Root element now creates a stacking context unconditionally. Refactored
display list builder to correctly bucket stacking participants into three
groups (negative/zero/positive z-index) per Appendix E steps 2/6/7.
Fixed z-index:0 elements painting at step 7 instead of step 6, and
descendant stacking contexts being trapped inside positioned z-index:auto
ancestors instead of participating in the parent stacking context.

Added StackingBuckets struct, unified step-6 rendering with tree-order
merge by node_id, and 7 unit tests for creates_stacking_context().
Added 6 golden tests (213-218) and 4 integration tests asserting
paint-order invariants programmatically.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-13 19:30:31 -04:00

39 lines
970 B
HTML

<!DOCTYPE html>
<html>
<head>
<style>
.container {
position: relative;
width: 200px;
height: 150px;
background-color: lightgray;
z-index: 0;
}
/* z-index:auto positioned element should paint at step 6 */
.auto {
position: relative;
width: 80px;
height: 40px;
background-color: red;
/* z-index defaults to auto (not set) */
}
/* z-index:0 stacking context should also paint at step 6,
interleaved with auto in tree order */
.zero {
position: relative;
width: 80px;
height: 40px;
background-color: blue;
z-index: 0;
}
</style>
</head>
<body>
<div class="container">
<div class="auto">Auto</div>
<div class="zero">Zero</div>
<div class="auto">Auto2</div>
</div>
</body>
</html>