dom-layout-shim 0.4.0

Minor Changes

• 1a58c8d: Include accessible linked stylesheets and constructable stylesheets in layout.
  The engine now follows document and adoption order and automatically recomputes
  geometry after CSSOM edits or changes to document.adoptedStyleSheets.

  const sheet = new window.CSSStyleSheet();
  sheet.replaceSync(".dialog { position: fixed; inset: 0 }");
  window.document.adoptedStyleSheets = [sheet];
  
  await attachLayoutEngine({ window });
  
  // Now covers the configured viewport; previously this sheet was ignored.
  dialog.getBoundingClientRect();

• 5189aa2: Apply responsive stylesheet @media rules against the viewport configured for
  the layout engine. Media types, dimensions, orientation, aspect ratio, query
  lists, conjunctions, and nested rules now select the same branches as Chromium.

  Previously, media rules were rejected by the unsupported CSS policy. After
  upgrading, matching rules contribute layout:

  document.head.innerHTML = `
    <style>@media (max-width: 600px) { #panel { width: 100px } }</style>
  `;
  document.body.innerHTML = '<div id="panel"></div>';
  
  await attachLayoutEngine({ window, viewport: { width: 480, height: 800 } });
  document.querySelector("#panel").offsetWidth; // 100

• 2b49074: Support rectangular named grid templates through grid-template-areas and
  single-name grid-area placement. Named areas can span rows and columns and may
  be arranged around unnamed . cells.

  Previously, named templates were rejected as unsupported CSS. After upgrading,
  items use the declared area bounds:

  document.body.innerHTML = `
    <main style='display:grid; grid-template-columns:80px 120px;
      grid-template-areas:"nav content"'>
      <article id="content" style="grid-area:content"></article>
    </main>
  `;
  
  await attachLayoutEngine({ window });
  document.querySelector("#content").offsetLeft; // 80

• c86fc03: Resolve CSS custom properties before parsing supported layout declarations.
  Inherited values, local overrides, forward references, nested fallbacks, and
  cyclic references now follow their CSS variable semantics, while values that
  remain unresolved route through unsupportedCss.

  Previously, a supported declaration such as width: var(--card-width) was
  ignored as an unsupported value. After upgrading, it contributes layout:

  document.body.innerHTML = `
    <main style="--card-width: 240px">
      <article id="card" style="width:var(--card-width)"></article>
    </main>
  `;
  
  await attachLayoutEngine({ window });
  document.querySelector("#card").offsetWidth; // 240

• 97a9a85: Support position: sticky for physical insets, scrolling ancestors, viewport
  scrolling, containing-block limits, hit testing, and simple table headers.

  scroller.scrollTop = 50;
  
  // Now remains at the scroller's top inset; previously `sticky` was rejected.
  toolbar.getBoundingClientRect().top;

Patch Changes

• fa4068f: Make CSS support evidence explain the independently supported behaviors within
  each topic. The exported inventory now provides descriptive, behavior-specific
  claims instead of broad current-supported-scope entries, and its prose marks
  CSS syntax and API names as inline code for documentation renderers.

  const grid = cssSupportInventory.find((topic) => topic.id === "grid-layout");
  
  // Now identifies explicit tracks, auto flow, line placement, area placement,
  // and shared placement behavior as separate claims with their own evidence.
  grid?.claims.map((claim) => claim.id);

  The CSS support explorer also separates implementation support from Chromium
  verification, explains metadata with tooltips, groups dense claim sections,
  and previews parity test sources without leaving the page.

• a8f464c: Make documentation navigation respond immediately after the initial page load.
  The shared shell now swaps internal page content and styles without reloading
  the document, while direct URLs, refreshes, Back and Forward navigation, scroll
  restoration, page-specific behavior, and no-JavaScript fallback navigation
  continue to work normally.

  For example, following the CSS support navigation link updates the URL and
  support explorer in place instead of triggering another document load.