|  | <!DOCTYPE html> | 
|  | <title>Tests that finding a default anchor triggers the new scrollable containing-block.</title> | 
|  | <link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/"> | 
|  | <link rel="help" href="https://drafts.csswg.org/css-position-4/#scrollable-containing-block"> | 
|  | <link rel="help" href="https://github.com/w3c/csswg-drafts/issues/12552"> | 
|  | <style> | 
|  | .scroller { | 
|  | /* Use overflow hidden instead of scroll to mitigate scrollbar differences. */ | 
|  | overflow: hidden; | 
|  | position: relative; | 
|  | width: 80px; | 
|  | height: 80px; | 
|  | margin: 10px; | 
|  | border: solid 3px; | 
|  | padding: 10px; | 
|  | } | 
|  |  | 
|  | .filler { | 
|  | min-width: 180px; | 
|  | min-height: 180px; | 
|  | } | 
|  |  | 
|  | .anchor { | 
|  | anchor-name: --a; | 
|  | } | 
|  |  | 
|  | .target { | 
|  | position: absolute; | 
|  | inset: 0; | 
|  | place-self: stretch; | 
|  | } | 
|  | </style> | 
|  | <script src="/resources/testharness.js"></script> | 
|  | <script src="/resources/testharnessreport.js"></script> | 
|  | <script src="/resources/check-layout-th.js"></script> | 
|  | <body onload="checkLayout('.target')"> | 
|  |  | 
|  | <!-- No default anchor should use the regular containing-block. --> | 
|  | <div class="scroller"> | 
|  | <div class="filler"><div class="anchor"></div></div> | 
|  | <div class="target" data-expected-width="100" data-expected-height="100"></div> | 
|  | </div> | 
|  |  | 
|  | <!-- A default anchor - should use the scrollable containing-block. --> | 
|  | <div class="scroller"> | 
|  | <div class="filler"><div class="anchor"></div></div> | 
|  | <div class="target" style="position-anchor: --a;" data-expected-width="200" data-expected-height="200"></div> | 
|  | </div> | 
|  |  | 
|  | <!-- A non-valid default anchor - should use the regular containing-block. --> | 
|  | <div class="scroller"> | 
|  | <div class="filler"><div class="anchor"></div></div> | 
|  | <div class="target" style="position-anchor: --b;" data-expected-width="100" data-expected-height="100"></div> | 
|  | </div> | 
|  |  | 
|  | <!-- Only specifying position-area - should use the regular containing-block. --> | 
|  | <div class="scroller"> | 
|  | <div class="filler"><div class="anchor"></div></div> | 
|  | <div class="target" style="position-area: top;" data-expected-width="100" data-expected-height="100"></div> | 
|  | </div> |