Testcase: https://knowler.dev/demos/Ats2b5t?codepen <div id="sticky">Sticky <div id="anchor">Anchor</div> <div id="anchored" popover="auto">Anchored</div> </div> <div id="content"></div> <script> anchored.showPopover(); </script> <style> #sticky { position: sticky; inset-block-start: 0; } #anchor { anchor-name: --anchor; } #anchored { position-anchor: --anchor; position-area: block-end span-inline-start; margin-block-start: 8px; } /* Presentation-only */ :root { color-scheme: dark; font-family: system-ui; background-image: linear-gradient(to bottom, RoyalBlue, MediumSeaGreen); } body { margin: 0; } #sticky { display: flex; justify-content: space-between; padding: 16px; background-color: DeepPink; font-weight: 600; } #content { block-size: 2000px; } </style>