[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"verticals":3,"playground-prefers-reduced-motion-respect-the-setting":44,"search-suggestions":58},[4,20,32],{"id":5,"slug":6,"name":7,"tagline":8,"description":9,"accentFrom":10,"accentTo":11,"icon":12,"defaultLocale":13,"locales":14,"features":16,"position":19},"019fe637-3d33-714b-b57f-23e163ffca0c","dev","Web Development","Read it. Run it. Prove it.","A post a day on modern web development — most with an editable playground and a quiz that explains every answer. Free, no account needed.","violet-500","cyan-400","◇","en",[13,15],"fa",{"courses":17,"paths":17,"articles":17,"exams":18,"flashcards":18,"packages":17,"community":17,"certificates":17,"teams":17,"commerce":17},true,false,0,{"id":21,"slug":22,"name":23,"tagline":24,"description":25,"accentFrom":26,"accentTo":10,"icon":27,"defaultLocale":13,"locales":28,"features":30,"position":31},"019fe637-3dc2-754c-8657-0f175bfee7c6","lang","Languages","Learn a language the way you learn a codebase.","Grammar explained the way good documentation explains an API — one idea at a time, each with a quiz.","amber-400","⌘",[13,15,29],"es",{"courses":18,"paths":18,"articles":17,"exams":18,"flashcards":17,"packages":18,"community":17,"certificates":17,"teams":18,"commerce":18},2,{"id":33,"slug":34,"name":35,"tagline":36,"description":37,"accentFrom":38,"accentTo":39,"icon":40,"defaultLocale":13,"locales":41,"features":42,"position":43},"7b3c16f2-931d-410e-802e-e1fa4edab7de","soft","Soft Skills","The half of the job nobody wrote documentation for.","Weekly, on the parts of working life that decide more than your code does — first weeks, meetings, interviews, promotions, and the people around you. Written from what actually happens, and recorded as a podcast you can listen to on the walk.","emerald-400","teal-300","◉",[13],{"courses":18,"paths":18,"articles":17,"exams":18,"flashcards":18,"packages":18,"community":17,"certificates":18,"teams":18,"commerce":18},3,{"slug":45,"title":46,"summary":47,"html":48,"css":49,"js":50,"config":51,"doc":53},"prefers-reduced-motion-respect-the-setting","prefers-reduced-motion — interactive playground",null,"\u003Cdiv class=\"pg\">\n    \u003Ch1 class=\"pg-title\">🎮 \u003Ccode>prefers-reduced-motion\u003C\u002Fcode> — one setting, three ways to honor it\u003C\u002Fh1>\n    \u003Cp class=\"pg-sub\">\n      Pick an environment below and hit \u003Cb>Replay entrance\u003C\u002Fb>. Watch which of the three implementations\n      moves and which stays still — only one of them gets it right in every environment.\n    \u003C\u002Fp>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">1\u003C\u002Fspan> Your actual browser setting\u003C\u002Fdiv>\n      \u003Cdiv class=\"badge-row\">\n        \u003Cspan class=\"pill\" id=\"realBadge\">checking…\u003C\u002Fspan>\n        \u003Cspan class=\"hint\" style=\"margin:0\">\n          This reads \u003Ccode>matchMedia(\"(prefers-reduced-motion: reduce)\")\u003C\u002Fcode> live — flip \"Reduce motion\"\n          in your OS accessibility settings right now and watch it change with no reload.\n        \u003C\u002Fspan>\n      \u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">2\u003C\u002Fspan> Simulate an environment\u003C\u002Fdiv>\n      \u003Cp class=\"hint\" style=\"margin-top:0\">\n        You can't flip someone else's OS setting to try this, so simulate the three environments\n        your CSS actually has to handle:\n      \u003C\u002Fp>\n      \u003Cdiv class=\"presets\" role=\"group\" aria-label=\"Simulated environment\">\n        \u003Cdiv class=\"seg\" id=\"simSeg\">\n          \u003Cbutton type=\"button\" data-sim=\"no-preference\" aria-pressed=\"true\">No preference\u003C\u002Fbutton>\n          \u003Cbutton type=\"button\" data-sim=\"reduce\" aria-pressed=\"false\">Reduce motion\u003C\u002Fbutton>\n          \u003Cbutton type=\"button\" data-sim=\"unsupported\" aria-pressed=\"false\">Old \u002F unsupported browser\u003C\u002Fbutton>\n        \u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n      \u003Cdiv class=\"btn-row\" style=\"margin-top:14px\">\n        \u003Cbutton class=\"btn primary\" id=\"replay\">▶️ Replay entrance\u003C\u002Fbutton>\n      \u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">3\u003C\u002Fspan> Result — three ways to write the same swoop-in\u003C\u002Fdiv>\n      \u003Cdiv class=\"cards\">\n        \u003Cdiv class=\"card\">\n          \u003Ch4>A — no handling\u003C\u002Fh4>\n          \u003Cp>Ignores the setting completely.\u003C\u002Fp>\n          \u003Cdiv class=\"swatch\" id=\"cardA\">\u003C\u002Fdiv>\n          \u003Cdiv class=\"result\" id=\"resultA\">\u003C\u002Fdiv>\n        \u003C\u002Fdiv>\n        \u003Cdiv class=\"card\">\n          \u003Ch4>B — opt out of motion\u003C\u002Fh4>\n          \u003Cp>Animates by default; \u003Ccode>@media (reduce)\u003C\u002Fcode> turns it off.\u003C\u002Fp>\n          \u003Cdiv class=\"swatch\" id=\"cardB\">\u003C\u002Fdiv>\n          \u003Cdiv class=\"result\" id=\"resultB\">\u003C\u002Fdiv>\n        \u003C\u002Fdiv>\n        \u003Cdiv class=\"card\">\n          \u003Ch4>C — opt in to motion\u003C\u002Fh4>\n          \u003Cp>Still by default; \u003Ccode>@media (no-preference)\u003C\u002Fcode> turns it on.\u003C\u002Fp>\n          \u003Cdiv class=\"swatch\" id=\"cardC\">\u003C\u002Fdiv>\n          \u003Cdiv class=\"result\" id=\"resultC\">\u003C\u002Fdiv>\n        \u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n      \u003Cdiv class=\"status\" id=\"status\" style=\"margin-top:14px\" aria-live=\"polite\">\n        \u003Cspan class=\"dot info\" id=\"dot\">\u003C\u002Fspan>\n        \u003Cspan id=\"statusText\">Pick an environment, then replay.\u003C\u002Fspan>\n      \u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">4\u003C\u002Fspan> The CSS behind B and C (what you'd actually ship)\u003C\u002Fdiv>\n      \u003Cdiv class=\"code\" id=\"code\">\u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">5\u003C\u002Fspan> Bonus — CSS can't touch a JS-driven loop\u003C\u002Fdiv>\n      \u003Cp class=\"hint\" style=\"margin-top:0\">\n        This dot moves on a plain \u003Ccode>requestAnimationFrame\u003C\u002Fcode> loop, the way a parallax layer or a\n        custom carousel might. No CSS \u003Ccode>@media\u003C\u002Fcode> query has any effect on it — only a JS check does.\n      \u003C\u002Fp>\n      \u003Clabel class=\"toggle\">\n        \u003Cinput type=\"checkbox\" id=\"jsRespect\" checked \u002F>\n        \u003Cspan class=\"switch\">\u003C\u002Fspan>\n        \u003Cspan>this loop checks \u003Ccode>matchMedia\u003C\u002Fcode> before it animates\u003C\u002Fspan>\n      \u003C\u002Flabel>\n      \u003Cdiv class=\"pg-ticker-stage\" style=\"margin-top:10px\">\n        \u003Cdiv class=\"pg-dot\" id=\"pgDot\">\u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n      \u003Cp class=\"hint\" id=\"jsHint\">\u003C\u002Fp>\n    \u003C\u002Fdiv>\n  \u003C\u002Fdiv>","\u002F*\n * Shared playground design system — daily-post\n * ============================================\n * Link it from any post's playground\u002Findex.html (no per-post boilerplate):\n *\n *   \u003Clink rel=\"stylesheet\" href=\"..\u002F..\u002F..\u002Fplayground\u002Fassets\u002Fbase.css\" \u002F>\n *\n * The relative path resolves the same locally (posts\u002F\u003Cbase>\u002Fplayground\u002F) and on\n * the deployed host (public\u002Fposts\u002F\u003Cbase>\u002Fplayground\u002F), because build-site.js\n * mirrors this file to public\u002Fplayground\u002Fassets\u002Fbase.css. For a CodeSandbox\n * --embed, playground.js inlines this file so the single-file sandbox still styles.\n *\n * Then write ONLY the demo-specific CSS in your inline \u003Cstyle>. Everything below\n * — tokens, layout, panels, buttons, toggles, sliders, code blocks, status\u002Flog,\n * banners, presets — comes for free and looks consistent across every post.\n *\n * Theme-aware: dark by default, light via prefers-color-scheme AND a\n * [data-theme] override on \u003Chtml> (so a toggle can force either). Accessible:\n * real focus rings, adequate contrast, reduced-motion honored.\n *\u002F\n\n\u002F* ---------- design tokens ---------- *\u002F\n:root {\n  --bg: #0d1117;\n  --bg-grid: #ffffff0a;\n  --panel: #161b22;\n  --panel-2: #0b0e14;\n  --card: #0b0e14;\n  --ink: #e8ebf2;\n  --muted: #9aa4b2;\n  --faint: #6b7688;\n  --line: #232a35;\n  --line-soft: #ffffff12;\n  --accent: #7c9cff;\n  --accent-ink: #0b0e14;\n  --good: #3fb950;\n  --warn: #f0883e;\n  --bad: #f85149;\n  --info: #58a6ff;\n  --radius: 14px;\n  --radius-sm: 9px;\n  --shadow: 0 8px 30px #0006;\n  --shadow-sm: 0 4px 14px #0005;\n  --mono: ui-monospace, SFMono-Regular, \"SF Mono\", Menlo, Consolas, \"Liberation Mono\", monospace;\n  --sans: ui-sans-serif, system-ui, -apple-system, \"Segoe UI\", Roboto, \"Helvetica Neue\", sans-serif;\n  color-scheme: dark;\n}\n\n\u002F* Light theme — system preference, overridable by [data-theme] on \u003Chtml>. *\u002F\n@media (prefers-color-scheme: light) {\n  :root:not([data-theme=\"dark\"]) {\n    --bg: #f4f6fb;\n    --bg-grid: #00000008;\n    --panel: #ffffff;\n    --panel-2: #f0f3f9;\n    --card: #f7f9fc;\n    --ink: #131722;\n    --muted: #5b6472;\n    --faint: #8a93a3;\n    --line: #e2e7f0;\n    --line-soft: #00000010;\n    --accent: #2f6df0;\n    --accent-ink: #ffffff;\n    --good: #1a7f37;\n    --warn: #bc4c00;\n    --bad: #cf222e;\n    --info: #0969da;\n    --shadow: 0 8px 30px #0000001f;\n    --shadow-sm: 0 4px 14px #00000014;\n    color-scheme: light;\n  }\n}\n:root[data-theme=\"light\"] {\n  --bg: #f4f6fb;\n  --bg-grid: #00000008;\n  --panel: #ffffff;\n  --panel-2: #f0f3f9;\n  --card: #f7f9fc;\n  --ink: #131722;\n  --muted: #5b6472;\n  --faint: #8a93a3;\n  --line: #e2e7f0;\n  --line-soft: #00000010;\n  --accent: #2f6df0;\n  --accent-ink: #ffffff;\n  --good: #1a7f37;\n  --warn: #bc4c00;\n  --bad: #cf222e;\n  --info: #0969da;\n  --shadow: 0 8px 30px #0000001f;\n  --shadow-sm: 0 4px 14px #00000014;\n  color-scheme: light;\n}\n\n\u002F* ---------- reset & base ---------- *\u002F\n*, *::before, *::after { box-sizing: border-box; }\n\nbody {\n  margin: 0;\n  min-height: 100vh;\n  font-family: var(--sans);\n  color: var(--ink);\n  background:\n    radial-gradient(circle at 1px 1px, var(--bg-grid) 1px, transparent 0) 0 0 \u002F 24px 24px,\n    var(--bg);\n  display: flex;\n  justify-content: center;\n  align-items: flex-start;\n  padding: clamp(14px, 3vw, 26px);\n  line-height: 1.55;\n  -webkit-font-smoothing: antialiased;\n  text-rendering: optimizeLegibility;\n}\n\n\u002F* The single content column. *\u002F\n.pg {\n  width: 100%;\n  max-width: 860px;\n}\n\n\u002F* ---------- header ---------- *\u002F\n.pg-title {\n  font-size: clamp(1.15rem, 1rem + 1vw, 1.4rem);\n  font-weight: 800;\n  letter-spacing: -0.02em;\n  margin: 0 0 4px;\n  display: flex;\n  align-items: center;\n  gap: 9px;\n}\n.pg-sub {\n  color: var(--muted);\n  font-size: 0.92rem;\n  line-height: 1.5;\n  margin: 0 0 16px;\n  max-width: 66ch;\n}\n.pg-sub strong, .pg-sub b { color: var(--ink); font-weight: 700; }\n.pg-sub code { font-family: var(--mono); background: var(--line-soft); color: var(--accent);\n  padding: 1px 6px; border-radius: 6px; font-size: 0.85em; }\n\n\u002F* ---------- panels ---------- *\u002F\n.panel {\n  background: var(--panel);\n  border: 1px solid var(--line);\n  border-radius: var(--radius);\n  padding: 16px 18px;\n  margin-bottom: 14px;\n  box-shadow: var(--shadow-sm);\n}\n.panel-label {\n  font-size: 0.7rem;\n  text-transform: uppercase;\n  letter-spacing: 0.08em;\n  color: var(--muted);\n  font-weight: 800;\n  margin: 0 0 13px;\n  display: flex;\n  align-items: center;\n  gap: 8px;\n}\n.panel-label .n {\n  display: inline-grid; place-items: center;\n  width: 18px; height: 18px; border-radius: 50%;\n  background: var(--accent); color: var(--accent-ink);\n  font-size: 0.66rem; font-weight: 800;\n}\n\n\u002F* ---------- layout helpers ---------- *\u002F\n.row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }\n.row.between { justify-content: space-between; }\n.col { display: flex; flex-direction: column; gap: 10px; }\n.grow { flex: 1 1 0; min-width: 0; }\n.wrap-controls { display: flex; flex-wrap: wrap; gap: 16px 24px; align-items: flex-end; }\n.field { display: flex; flex-direction: column; gap: 7px; min-width: 0; }\n.field > .label, .ctl-label {\n  font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.04em;\n  color: var(--muted); font-weight: 800;\n}\n\n\u002F* ---------- buttons ---------- *\u002F\n.btn {\n  font: inherit; font-weight: 650; font-size: 0.88rem;\n  cursor: pointer; user-select: none;\n  border: 1px solid var(--line);\n  background: var(--card); color: var(--ink);\n  padding: 9px 15px; border-radius: var(--radius-sm);\n  display: inline-flex; align-items: center; gap: 8px;\n  transition: background .15s ease, border-color .15s ease, transform .05s ease, color .15s ease;\n}\n.btn:hover { background: var(--line-soft); border-color: var(--muted); }\n.btn:active { transform: translateY(1px); }\n.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }\n.btn[disabled] { opacity: 0.45; cursor: not-allowed; }\n.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }\n.btn.primary:hover { filter: brightness(1.08); background: var(--accent); }\n.btn.good { background: var(--good); border-color: var(--good); color: #04140a; }\n.btn.bad  { background: var(--bad);  border-color: var(--bad);  color: #fff; }\n.btn.ghost { background: transparent; }\n.btn.sm { padding: 6px 11px; font-size: 0.82rem; }\n\n.btn-row { display: flex; flex-wrap: wrap; gap: 9px; }\n\n\u002F* Segmented control — a row of buttons where one is active (aria-pressed). *\u002F\n.seg { display: inline-flex; background: var(--card); border: 1px solid var(--line);\n  border-radius: var(--radius-sm); padding: 3px; gap: 3px; }\n.seg button {\n  font: inherit; font-weight: 650; font-size: 0.84rem; cursor: pointer;\n  border: none; background: transparent; color: var(--muted);\n  padding: 7px 13px; border-radius: 7px;\n  transition: background .15s ease, color .15s ease;\n}\n.seg button:hover { color: var(--ink); }\n.seg button[aria-pressed=\"true\"] { background: var(--accent); color: var(--accent-ink); }\n.seg button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }\n\n\u002F* Preset chips — worked-example shortcuts. *\u002F\n.presets { display: flex; flex-wrap: wrap; gap: 8px; }\n.presets .btn { background: var(--panel-2); }\n\n\u002F* ---------- toggle switch ---------- *\u002F\n.toggle { display: inline-flex; align-items: center; gap: 10px; cursor: pointer;\n  font-size: 0.88rem; font-weight: 600; user-select: none; }\n.toggle input { position: absolute; opacity: 0; width: 0; height: 0; }\n.switch { position: relative; width: 44px; height: 25px; border-radius: 999px; flex: none;\n  background: var(--line); border: 1px solid var(--line); transition: background .18s ease; }\n.switch::after { content: \"\"; position: absolute; top: 2px; left: 2px; width: 19px; height: 19px;\n  border-radius: 50%; background: #cfd6e4; transition: transform .18s ease; box-shadow: 0 1px 3px #0006; }\n.toggle input:checked + .switch { background: var(--good); border-color: var(--good); }\n.toggle input:checked + .switch::after { transform: translateX(19px); background: #fff; }\n.toggle input:focus-visible + .switch { outline: 2px solid var(--accent); outline-offset: 2px; }\n\n\u002F* ---------- range slider ---------- *\u002F\ninput[type=\"range\"] {\n  -webkit-appearance: none; appearance: none; width: 100%; height: 6px;\n  background: var(--line); border-radius: 999px; outline: none; cursor: pointer; margin: 8px 0;\n}\ninput[type=\"range\"]::-webkit-slider-thumb {\n  -webkit-appearance: none; appearance: none; width: 19px; height: 19px; border-radius: 50%;\n  background: var(--accent); border: 2px solid var(--panel); box-shadow: var(--shadow-sm); cursor: pointer;\n}\ninput[type=\"range\"]::-moz-range-thumb {\n  width: 19px; height: 19px; border-radius: 50%; background: var(--accent);\n  border: 2px solid var(--panel); box-shadow: var(--shadow-sm); cursor: pointer;\n}\ninput[type=\"range\"]:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }\n\n\u002F* ---------- text inputs \u002F selects ---------- *\u002F\ninput[type=\"text\"], input[type=\"number\"], input[type=\"search\"], select, textarea {\n  font: inherit; color: var(--ink); background: var(--card);\n  border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 8px 11px; width: 100%;\n}\ntextarea { font-family: var(--mono); font-size: 0.85rem; line-height: 1.6; resize: vertical; }\ninput:focus-visible, select:focus-visible, textarea:focus-visible {\n  outline: 2px solid var(--accent); outline-offset: 1px; border-color: var(--accent);\n}\n\n\u002F* ---------- status \u002F output \u002F log ---------- *\u002F\n.status {\n  display: flex; align-items: center; gap: 9px; flex-wrap: wrap;\n  font-size: 0.9rem; font-weight: 600;\n  padding: 11px 14px; border-radius: var(--radius-sm);\n  background: var(--panel-2); border: 1px solid var(--line); color: var(--ink);\n}\n.status.good { border-color: color-mix(in srgb, var(--good) 55%, var(--line)); }\n.status.warn { border-color: color-mix(in srgb, var(--warn) 55%, var(--line)); }\n.status.bad  { border-color: color-mix(in srgb, var(--bad) 55%, var(--line)); }\n.dot { width: 9px; height: 9px; border-radius: 50%; background: var(--muted); flex: none; }\n.dot.good { background: var(--good); } .dot.warn { background: var(--warn); }\n.dot.bad { background: var(--bad); } .dot.info { background: var(--info); }\n\n.output { background: var(--panel-2); border: 1px solid var(--line); border-radius: var(--radius-sm);\n  padding: 13px 15px; }\n.log { font-family: var(--mono); font-size: 0.8rem; line-height: 1.7; background: var(--card);\n  border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 11px 14px;\n  max-height: 220px; overflow-y: auto; white-space: pre-wrap; }\n\n\u002F* ---------- code block + syntax tokens ---------- *\u002F\n.code {\n  font-family: var(--mono); font-size: 0.82rem; line-height: 1.7;\n  background: var(--panel-2); border: 1px solid var(--line); border-radius: var(--radius-sm);\n  padding: 13px 15px; overflow-x: auto; white-space: pre; tab-size: 2;\n}\n.code .tok-sel  { color: var(--accent); }\n.code .tok-prop { color: #86e29b; }\n.code .tok-kw   { color: #ff9bcb; }\n.code .tok-str  { color: #f0c674; }\n.code .tok-num  { color: #f0883e; }\n.code .tok-cmt  { color: var(--faint); font-style: italic; }\n.code .hl { background: color-mix(in srgb, var(--good) 22%, transparent); border-radius: 4px; padding: 0 3px; }\n\n\u002F* ---------- hint \u002F caption ---------- *\u002F\n.hint { font-size: 0.83rem; color: var(--muted); line-height: 1.55; margin: 10px 0 0; }\n.hint code { font-family: var(--mono); color: var(--ink); background: var(--line-soft);\n  padding: 1px 5px; border-radius: 5px; font-size: 0.86em; }\n.hint strong { color: var(--ink); }\n\n\u002F* ---------- banner (feature-support \u002F notices) ---------- *\u002F\n.banner {\n  display: none; margin-bottom: 14px; padding: 11px 14px; border-radius: 11px;\n  font-size: 0.85rem; line-height: 1.5;\n  color: var(--ink); background: color-mix(in srgb, var(--warn) 12%, var(--panel));\n  border: 1px solid color-mix(in srgb, var(--warn) 45%, var(--line));\n}\n.banner.show { display: block; }\n.banner.info { background: color-mix(in srgb, var(--info) 12%, var(--panel));\n  border-color: color-mix(in srgb, var(--info) 45%, var(--line)); }\n.banner code { font-family: var(--mono); background: var(--line-soft); padding: 1px 5px; border-radius: 5px; }\n\n\u002F* ---------- misc atoms ---------- *\u002F\n.pill { display: inline-flex; align-items: center; gap: 6px; font-size: 0.75rem; font-weight: 700;\n  padding: 3px 9px; border-radius: 999px; background: var(--line-soft); color: var(--muted); }\n.pill.good { color: var(--good); background: color-mix(in srgb, var(--good) 16%, transparent); }\n.pill.bad  { color: var(--bad);  background: color-mix(in srgb, var(--bad) 16%, transparent); }\n.mono { font-family: var(--mono); }\n.muted { color: var(--muted); }\n.big-num { font-family: var(--mono); font-size: 1.6rem; font-weight: 800; letter-spacing: -0.02em; }\n\n\u002F* Optional theme toggle button (top-right). Wire it in JS if you want it. *\u002F\n.theme-btn { position: fixed; top: 12px; right: 12px; z-index: 20; }\n\n\u002F* ---------- responsive ---------- *\u002F\n@media (max-width: 560px) {\n  .panel { padding: 14px; }\n  .wrap-controls { gap: 14px; }\n  .btn { padding: 9px 13px; }\n}\n\n\u002F* ---------- reduced motion ---------- *\u002F\n@media (prefers-reduced-motion: reduce) {\n  *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }\n}\n\n\n\u002F* Demo-specific CSS ONLY. base.css already provides tokens, layout, panels,\n     buttons, toggles, sliders, code blocks, status\u002Flog, banners, presets. *\u002F\n\n  .cards {\n    display: grid;\n    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));\n    gap: 12px;\n    margin-top: 4px;\n  }\n  .card {\n    background: var(--card);\n    border: 1px solid var(--line);\n    border-radius: var(--radius-sm);\n    padding: 14px 14px 16px;\n    min-height: 118px;\n  }\n  .card h4 {\n    margin: 0 0 4px;\n    font-size: 0.85rem;\n  }\n  .card p {\n    margin: 0 0 10px;\n    font-size: 0.75rem;\n    color: var(--muted);\n    line-height: 1.4;\n  }\n  .card .swatch {\n    width: 34px;\n    height: 34px;\n    border-radius: 9px;\n    background: var(--accent);\n    opacity: 1;\n    transform: none;\n  }\n  \u002F* The entrance motion itself — identical big transform+fade on every card.\n     Whether it plays is controlled entirely by which selector below matches\n     the current data-sim state, which is the whole point of the demo. *\u002F\n  @keyframes swoop-in {\n    from { opacity: 0; transform: translateY(14px) scale(0.6); }\n    to   { opacity: 1; transform: translateY(0) scale(1); }\n  }\n  .card .swatch.playing { animation: swoop-in 650ms ease-out; }\n\n  .card .result {\n    margin-top: 10px;\n    font-size: 0.72rem;\n    font-weight: 600;\n  }\n  .card .result.moved { color: var(--good, #4ade80); }\n  .card .result.still { color: var(--muted); }\n\n  .pg-ticker-stage {\n    position: relative;\n    height: 56px;\n    border: 1px dashed var(--line);\n    border-radius: var(--radius-sm);\n    background: var(--panel-2);\n    overflow: hidden;\n    margin-top: 4px;\n  }\n  .pg-dot {\n    position: absolute;\n    top: 50%;\n    left: 8px;\n    width: 18px;\n    height: 18px;\n    margin-top: -9px;\n    border-radius: 50%;\n    background: var(--accent);\n  }\n\n  .badge-row {\n    display: flex;\n    align-items: center;\n    gap: 10px;\n    flex-wrap: wrap;\n  }","\"use strict\";\n  const $ = (id) => document.getElementById(id);\n\n  const realBadge = $(\"realBadge\");\n  const simSeg = $(\"simSeg\");\n  const replayBtn = $(\"replay\");\n  const statusText = $(\"statusText\");\n  const dot = $(\"dot\");\n  const codeEl = $(\"code\");\n  const jsRespect = $(\"jsRespect\");\n  const jsHint = $(\"jsHint\");\n  const pgDot = $(\"pgDot\");\n\n  let sim = \"no-preference\";\n\n  \u002F\u002F --- 1. the real, live OS-level signal -------------------------------------\n  const realMQ = window.matchMedia(\"(prefers-reduced-motion: reduce)\");\n  function paintRealBadge() {\n    realBadge.textContent = realMQ.matches\n      ? \"Your OS says: reduce motion\"\n      : \"Your OS says: no preference\";\n  }\n  paintRealBadge();\n  realMQ.addEventListener(\"change\", paintRealBadge);\n\n  \u002F\u002F --- 2 & 3. the three simulated implementations ----------------------------\n  \u002F\u002F Whether each card's swoop-in plays, for a given simulated environment.\n  \u002F\u002F This mirrors EXACTLY what the real @media queries in the code panel would\n  \u002F\u002F do: A always matches (no query at all); B's override query only matches\n  \u002F\u002F \"reduce\"; C's gating query only matches \"no-preference\". \"unsupported\"\n  \u002F\u002F means NEITHER query can ever match, which is the whole point of card C.\n  function playsFor(card, simState) {\n    if (card === \"A\") return true; \u002F\u002F no query — always animates\n    if (card === \"B\") return simState !== \"reduce\"; \u002F\u002F off only when reduce matches\n    if (card === \"C\") return simState === \"no-preference\"; \u002F\u002F on only when it matches\n  }\n\n  function setStatus(text, kind = \"info\") {\n    statusText.textContent = text;\n    dot.className = \"dot \" + kind;\n  }\n\n  function replay() {\n    let movedCount = 0;\n    for (const card of [\"A\", \"B\", \"C\"]) {\n      const el = $(\"card\" + card);\n      const resultEl = $(\"result\" + card);\n      el.classList.remove(\"playing\");\n      \u002F\u002F force reflow so the animation can restart even if it already ran\n      void el.offsetWidth;\n      const willMove = playsFor(card, sim);\n      if (willMove) {\n        el.classList.add(\"playing\");\n        movedCount++;\n        resultEl.textContent = \"moved\";\n        resultEl.className = \"result moved\";\n      } else {\n        resultEl.textContent = \"stayed still\";\n        resultEl.className = \"result still\";\n      }\n    }\n    const label = { \"no-preference\": \"No preference\", reduce: \"Reduce motion\", unsupported: \"Old \u002F unsupported browser\" }[sim];\n    if (sim === \"reduce\") {\n      setStatus(`${label}: A still moved anyway (the bug). B and C correctly stayed still.`, movedCount === 1 ? \"good\" : \"warn\");\n    } else if (sim === \"unsupported\") {\n      setStatus(`${label}: A and B both moved (B's override never fired — no support means no match). Only C, gated the other way, stayed still.`, \"warn\");\n    } else {\n      setStatus(`${label}: all three look identical — the difference only shows up once you change the environment.`, \"info\");\n    }\n  }\n\n  simSeg.addEventListener(\"click\", (e) => {\n    const btn = e.target.closest(\"button[data-sim]\");\n    if (!btn) return;\n    sim = btn.dataset.sim;\n    [...simSeg.querySelectorAll(\"button\")].forEach((b) => b.setAttribute(\"aria-pressed\", String(b === btn)));\n    replay();\n  });\n  replayBtn.addEventListener(\"click\", replay);\n\n  codeEl.innerHTML =\n`\u003Cspan class=\"tok-cmt\">\u002F* B — opt OUT of motion: animates unless \"reduce\" is confirmed *\u002F\u003C\u002Fspan>\n\u003Cspan class=\"tok-sel\">.swatch\u003C\u002Fspan> { \u003Cspan class=\"tok-prop\">animation\u003C\u002Fspan>: swoop-in \u003Cspan class=\"tok-num\">650ms\u003C\u002Fspan> ease-out; }\n\u003Cspan class=\"tok-kw\">@media\u003C\u002Fspan> (prefers-reduced-motion: reduce) {\n  \u003Cspan class=\"tok-sel\">.swatch\u003C\u002Fspan> { \u003Cspan class=\"tok-prop\">animation\u003C\u002Fspan>: none; }\n}\n\n\u003Cspan class=\"tok-cmt\">\u002F* C — opt IN to motion: still unless \"no-preference\" is confirmed *\u002F\u003C\u002Fspan>\n\u003Cspan class=\"tok-sel\">.swatch\u003C\u002Fspan> { \u003Cspan class=\"tok-prop\">animation\u003C\u002Fspan>: none; }\n\u003Cspan class=\"tok-kw\">@media\u003C\u002Fspan> (prefers-reduced-motion: no-preference) {\n  \u003Cspan class=\"tok-sel\">.swatch\u003C\u002Fspan> { \u003Cspan class=\"tok-prop\">animation\u003C\u002Fspan>: swoop-in \u003Cspan class=\"tok-num\">650ms\u003C\u002Fspan> ease-out; }\n}`;\n\n  \u002F\u002F --- 5. the JS-only loop that no @media query can reach --------------------\n  let raf = null;\n  let x = 8;\n  let dir = 1;\n  const MAX_X = 220;\n\n  function tick() {\n    x += dir * 2.4;\n    if (x > MAX_X || x \u003C 8) dir *= -1;\n    pgDot.style.left = x + \"px\";\n    raf = requestAnimationFrame(tick);\n  }\n  function startTicker() {\n    if (raf) return;\n    raf = requestAnimationFrame(tick);\n  }\n  function stopTicker() {\n    if (raf) cancelAnimationFrame(raf);\n    raf = null;\n  }\n\n  function syncTicker() {\n    const shouldRespect = jsRespect.checked;\n    const userWantsLess = sim === \"reduce\";\n    if (shouldRespect && userWantsLess) {\n      stopTicker();\n      jsHint.innerHTML = 'Respecting it, and the simulated environment is \u003Cb>\"Reduce motion\"\u003C\u002Fb> — the loop is paused, same as the real matchMedia check would do.';\n    } else {\n      startTicker();\n      jsHint.innerHTML = shouldRespect\n        ? 'Respecting it, and the simulated environment is not asking for less motion — the loop runs.'\n        : \"Ignoring the setting entirely — the loop keeps running no matter what you pick above. This is what a parallax script with no matchMedia check actually does.\";\n    }\n  }\n\n  jsRespect.addEventListener(\"change\", syncTicker);\n  simSeg.addEventListener(\"click\", syncTicker);\n\n  \u002F\u002F init\n  replay();\n  syncTicker();",{"height":52,"autorun":17},520,{"slug":45,"title":54,"excerpt":55,"coverUrl":56,"vertical":57},"You're Animating for Everyone. `prefers-reduced-motion` Fixes That.","Most animated UIs never check whether the visitor asked for less motion. `prefers-reduced-motion` is the CSS media feature that tells you — and a fail-closed pattern keeps you honest even when a browser doesn't support it.","\u002Fmedia\u002Fcovers\u002Fprefers-reduced-motion-respect-the-setting.png",{"slug":6},[59,63,67,71,75,79,83,87,91,95,98,102],{"slug":60,"name":61,"articles":62},"webdev","Webdev",129,{"slug":64,"name":65,"articles":66},"javascript","Javascript",106,{"slug":68,"name":69,"articles":70},"frontend","Frontend",81,{"slug":72,"name":73,"articles":74},"tutorial","Tutorial",49,{"slug":76,"name":77,"articles":78},"css","Css",41,{"slug":80,"name":81,"articles":82},"typescript","Typescript",18,{"slug":84,"name":85,"articles":86},"performance","Performance",16,{"slug":88,"name":89,"articles":90},"react","React",15,{"slug":92,"name":93,"articles":94},"browser","Browser",12,{"slug":96,"name":97,"articles":94},"node","Node",{"slug":99,"name":100,"articles":101},"html","Html",9,{"slug":103,"name":104,"articles":101},"accessibility","Accessibility"]