v146 · CSS · demo

Progressive Enhancement

Two product cards — one using a simple absolute-positioned tooltip as a fallback, and one that applies @supports named-feature("anchor-position-follows-transforms") to use a more precise anchor-positioned version in Chrome 150+.

Feature detection results in this browser

CSS.supports("named-feature(...)")
named-feature("anchor-position-follows-transforms")

Hover the ⓘ icon in each card to see the tooltip. The right card uses named-feature() to enhance behaviour when the feature is present.

Fallback — no named-feature() test
Ceramic Mug
SKU: MUG-01 · In stock
Dishwasher-safe · 350ml capacity

Uses position: absolute relative to the card — tooltip always appears at top-left of the card regardless of transforms.

Enhanced — @supports named-feature()
Glass Teapot
SKU: TEA-02 · In stock
Heat-resistant borosilicate · 600ml

In Chrome 150+: tooltip tracks the icon even through CSS transforms.

CSS comparison

Without named-feature()
.tooltip { /* Simple absolute positioning — doesn't account for transforms */ position: absolute; bottom: calc(100% + 6px); left: 0; } /* Works everywhere, but the tooltip won't track transforms on the anchor */
With named-feature() — Chrome 150
/* Base style — works everywhere */ .tooltip { position: absolute; … } /* Enhanced when transform tracking is available */ @supports named-feature( "anchor-position-follows-transforms" ) { .icon { anchor-name: --info; } .tooltip { position-anchor: --info; top: anchor(bottom); left: anchor(left); } }

see also