Add depth with a box shadow.

CSS: Box shadows are painted outside the box without reserving additional layout space.

CSS example.html
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Example</title>
<style>
.box { width:120px; box-shadow:0 2px 8px rgba(0,0,0,.2); }
</style>
</head>
<body>
<div class="box">Card</div>
</body>
</html>

Expected output EXAMPLE

At a 1000 × 800 CSS-pixel viewport, unless another size is stated:
The 120-pixel-wide box casts a shadow with an 8-pixel component and black at 20% opacity. The shadow does not increase the box's layout width.

Details

Save this complete fixture as example.html. The output describes layout or computed styles verified in Chromium. Box shadows are painted outside the box without reserving additional layout space.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · · Chromium 141.0.7390.37 · libc6 2.39-0ubuntu8.9; Playwright 1.56.0

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel
x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale
uid=65534, gid=65534 (unprivileged) / C.UTF-8
Interpreter invocation
Chromium: open example.html; execute the published browser assertions
Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd
Code SHA-256
b66e1bed8361003f3ba6aa37b1589ac18908d56c106364d0ae81bf002cfa1a1c
Dependencies
libc6 2.39-0ubuntu8.9; Playwright 1.56.0

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

Expected output describes the rendered page. The standard-output record below is the browser test harness receipt; the additional assertions check the result and interactions.

Add depth with a box shadow: browser checks passed.

Exit code: 0. Standard error: empty. Validation: Shape/content assertions. System-dependent values above are one recorded run.

Additional assertions that passed

Checks recorded by the test harness. Where Python assertions are shown, browser cases use Playwright and simulator cases may inspect pin transitions: result.stdout is captured output, work is the temporary directory, and Path is pathlib.Path. The harness also imports json and csv.

shadow=await page.locator('.box').evaluate('(e)=>getComputedStyle(e).boxShadow')
assert 'rgba(0, 0, 0, 0.2)' in shadow and '8px' in shadow
assert (await page.locator('.box').bounding_box())['width']==120