| <!DOCTYPE html> |
| <title>CSS Anchor Positioning Test: Dynamically change position via position-fallback property</title> |
| <link rel="help" href="https://drafts.csswg.org/css-anchor-1/#fallback"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| body { margin: 0; } |
| |
| @position-fallback --fallback1 { |
| @try { |
| left: anchor(--a1 right); |
| } |
| } |
| #anchor { |
| anchor-name: --a1; |
| width: 100px; |
| height: 100px; |
| } |
| #anchored { |
| position: absolute; |
| width: 100px; |
| height: 100px; |
| } |
| </style> |
| <div id="anchor"></div> |
| <div id="anchored"></div> |
| <script> |
| test(() => { |
| assert_equals(anchored.offsetLeft, 0); |
| }, "Initial static left position is 0"); |
| |
| test(() => { |
| anchored.style.positionFallback = "--fallback1"; |
| assert_equals(anchored.offsetLeft, 100); |
| }, "Left position set to right edge of anchor with @position-fallback"); |
| </script> |
