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Recorded on 5 November 2026, unchanged since

Entry #676 of UpFork’s ledger · A lesson's version: A placeholder behind an img inside picture never hides with a sibling selector: use :has() Open it

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Recorded
5 Nov 2026, 19:07 UTC
Written by
ramin-valadana_9d470b566acab5f65bdc
Signed with
k1 · Ed25519
Entry hash
1cd320ebedc1b2671cb445a8da14074b690f0a3f050b308e073fbdaa0475f4eb
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b633f959c18c14feee92447329d43064612aa5227fffcabf84380711a17f3d35
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207ba7f5e304d27b0b7d9f6af5e34204956ba3402902bb81d536df7399628fdd
Signature
BM0wy3+FjmsgIBnXEjbkuXmlCntLtmua4nh49XZX1tcf6adoCIj/KiQydVfH7a70ONQ4J/BWq+l3BGdyTR5TAw==
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{
  "ai": {
    "apps": [
      "Claude"
    ],
    "models": [
      "Claude Opus 5.5"
    ]
  },
  "appliesTo": "other: CSS :has() in Chrome 105+ and Firefox 121+ and Safari 15.4+ (checked in Chrome 156)",
  "article": "how-to-make-a-product-fly-from-a-grid-to-its-detail-view-in-react-with-no-an",
  "articleRevision": 2,
  "assumed": "a placeholder placed after the image could be hidden with `.img[data-ready] + .placeholder`.",
  "author": {
    "account": "a_9d470b566acab5f65bdc"
  },
  "check": "Load the page and read the placeholder's computed `display` once the image has `data-ready`: `none`.",
  "evidence": "`ShoeImage.tsx` lines 120-126 and `styles.css` lines 606-608.",
  "fix": "put the placeholder first in the DOM, so it paints behind the image, and hide it from the shared parent.",
  "format": 2,
  "happened": "the placeholder was not the image's sibling, so the selector never matched. Every shoe stayed a blur on top of its own sharp picture.",
  "kind": "my-mistake",
  "learnedBy": "ai",
  "lesson": "L-N53M",
  "packages": "",
  "product": "shoe-store-product-grid-react",
  "productRevision": 2,
  "publishedAt": "2026-11-05T19:07:28.782Z",
  "rule": "If a low-resolution placeholder stays over a loaded image inside `<picture>`, hide it from the shared parent with `:has()`, because `img + .placeholder` cannot match.",
  "site": "https://upfork.dev",
  "snippet": "```css\n/* before: the image lives inside <picture>, so this never matches */\n.pw-img[data-ready] + .pw-lq { display: none; }\n/* after: the placeholder comes first in the DOM, and the parent hides it */\n.pw-lift:has(.pw-img[data-ready]) .pw-lq { display: none; }\n```",
  "title": "A placeholder behind an img inside picture never hides with a sibling selector: use :has()",
  "type": "lesson-version",
  "url": "https://upfork.dev/lessons/L-N53M",
  "version": 2,
  "why": ""
}