[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"verticals":3,"playground-intl-relativetimeformat-relative-dates":32},[4,20],{"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","Build. Learn. Ship.","Practical courses, engineering-grade articles and open-source tools for people who ship.","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.","Structured paths, listening drills and spaced repetition that actually sticks.","amber-400","⌘",[13,15,29],"es",{"courses":17,"paths":17,"articles":18,"exams":18,"flashcards":18,"packages":18,"community":17,"certificates":18,"teams":18,"commerce":17},2,{"slug":33,"title":34,"summary":35,"html":36,"css":37,"js":38,"config":39,"doc":41},"intl-relativetimeformat-relative-dates","Intl.RelativeTimeFormat — interactive playground",null,"\u003Cdiv class=\"pg\">\n    \u003Ch1 class=\"pg-title\">🌍 Intl.RelativeTimeFormat live\u003C\u002Fh1>\n    \u003Cp class=\"pg-sub\">\n      Adjust the value, pick a unit and locale mode — watch the browser format it into\n      natural-language relative time, no library required.\n    \u003C\u002Fp>\n\n    \u003C!-- Panel 1: inputs -->\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">1\u003C\u002Fspan> Set the value and unit\u003C\u002Fdiv>\n      \u003Cdiv class=\"controls-grid\">\n        \u003Cdiv class=\"field\">\n          \u003Clabel class=\"label\" for=\"valInput\">Value (negative = past)\u003C\u002Flabel>\n          \u003Cinput type=\"number\" id=\"valInput\" value=\"-3\" style=\"width:100%;box-sizing:border-box;\" \u002F>\n        \u003C\u002Fdiv>\n        \u003Cdiv class=\"field\">\n          \u003Clabel class=\"label\" for=\"unitSel\">Unit\u003C\u002Flabel>\n          \u003Cselect id=\"unitSel\" style=\"width:100%;box-sizing:border-box;\">\n            \u003Coption value=\"second\">second\u003C\u002Foption>\n            \u003Coption value=\"minute\">minute\u003C\u002Foption>\n            \u003Coption value=\"hour\" selected>hour\u003C\u002Foption>\n            \u003Coption value=\"day\">day\u003C\u002Foption>\n            \u003Coption value=\"week\">week\u003C\u002Foption>\n            \u003Coption value=\"month\">month\u003C\u002Foption>\n            \u003Coption value=\"quarter\">quarter\u003C\u002Foption>\n            \u003Coption value=\"year\">year\u003C\u002Foption>\n          \u003C\u002Fselect>\n        \u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n      \u003Cdiv class=\"field\" style=\"margin-top:10px\">\n        \u003Clabel class=\"label\">numeric\u003C\u002Flabel>\n        \u003Cdiv class=\"auto-demo\" id=\"numericBtns\">\n          \u003Cbutton class=\"auto-chip\" data-v=\"always\">always\u003C\u002Fbutton>\n          \u003Cbutton class=\"auto-chip active\" data-v=\"auto\">auto \u003Cspan style=\"font-weight:normal;opacity:.7\">(gives \"yesterday\")\u003C\u002Fspan>\u003C\u002Fbutton>\n        \u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003C!-- Panel 2: main output -->\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">2\u003C\u002Fspan> Output (English)\u003C\u002Fdiv>\n      \u003Cdiv class=\"big-out\" id=\"mainOut\">—\u003C\u002Fdiv>\n      \u003Cdiv class=\"code-out\" id=\"codeOut\">\u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003C!-- Panel 3: locale comparison -->\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">3\u003C\u002Fspan> Same value, multiple locales\u003C\u002Fdiv>\n      \u003Cdiv class=\"locale-grid\" id=\"localeGrid\">\u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003C!-- Panel 4: auto-unit picker demo -->\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">4\u003C\u002Fspan> Auto-unit helper\u003C\u002Fdiv>\n      \u003Cp class=\"hint\">\n        The API doesn't pick the unit for you — but a tiny helper does. Click a preset to\n        see how elapsed time maps to the right unit automatically.\n      \u003C\u002Fp>\n      \u003Cdiv class=\"auto-demo\" id=\"presets\">\u003C\u002Fdiv>\n      \u003Cdiv class=\"big-out\" id=\"helperOut\" style=\"font-size:1.1rem;margin-top:12px\">—\u003C\u002Fdiv>\n      \u003Cdiv class=\"code-out\" id=\"helperCode\" style=\"margin-top:6px\">\u003C\u002Fdiv>\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.controls-grid {\n    display: grid;\n    grid-template-columns: 1fr 1fr;\n    gap: 10px;\n  }\n  @media (max-width: 480px) { .controls-grid { grid-template-columns: 1fr; } }\n\n  .locale-grid {\n    display: grid;\n    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));\n    gap: 8px;\n    margin-top: 10px;\n  }\n  .locale-card {\n    background: var(--panel-2);\n    border: 1px solid var(--line);\n    border-radius: var(--radius-sm);\n    padding: 10px 12px;\n  }\n  .locale-card .lc-tag {\n    font-family: var(--mono);\n    font-size: .7rem;\n    color: var(--muted);\n    margin-bottom: 4px;\n  }\n  .locale-card .lc-out {\n    font-family: var(--mono);\n    font-size: .88rem;\n    color: var(--accent);\n    word-break: break-word;\n  }\n\n  .big-out {\n    font-family: var(--mono);\n    font-size: 1.4rem;\n    font-weight: 700;\n    color: var(--accent);\n    min-height: 2rem;\n    margin: 8px 0 4px;\n  }\n\n  .code-out {\n    font-family: var(--mono);\n    font-size: .78rem;\n    background: var(--panel-2);\n    border: 1px solid var(--line);\n    border-radius: var(--radius-sm);\n    padding: 10px 12px;\n    margin-top: 8px;\n    white-space: pre-wrap;\n    word-break: break-word;\n  }\n\n  .auto-demo {\n    display: flex;\n    gap: 8px;\n    flex-wrap: wrap;\n    margin-top: 8px;\n  }\n  .auto-chip {\n    font-family: var(--mono);\n    font-size: .78rem;\n    padding: 4px 10px;\n    border-radius: 20px;\n    border: 1px solid var(--line);\n    background: var(--panel-2);\n    cursor: pointer;\n    transition: border-color .15s, background .15s;\n  }\n  .auto-chip:hover { border-color: var(--accent); background: var(--panel-3, var(--panel-2)); }\n  .auto-chip.active { border-color: var(--accent); color: var(--accent); font-weight: 700; }","\"use strict\";\nconst $ = id => document.getElementById(id);\n\nconst LOCALES = [\n  { tag: 'en', label: 'English' },\n  { tag: 'fr', label: 'French' },\n  { tag: 'de', label: 'German' },\n  { tag: 'ja', label: 'Japanese' },\n  { tag: 'ar', label: 'Arabic' },\n  { tag: 'es', label: 'Spanish' },\n  { tag: 'zh', label: 'Chinese' },\n  { tag: 'fa', label: 'Persian' },\n];\n\n\u002F\u002F Build locale cards\nconst grid = $('localeGrid');\nLOCALES.forEach(loc => {\n  const card = document.createElement('div');\n  card.className = 'locale-card';\n  card.innerHTML = `\u003Cdiv class=\"lc-tag\">${loc.tag} — ${loc.label}\u003C\u002Fdiv>\u003Cdiv class=\"lc-out\" id=\"loc-${loc.tag}\">—\u003C\u002Fdiv>`;\n  grid.appendChild(card);\n});\n\nlet numeric = 'auto';\n\nfunction fmt(val, unit, locale, num) {\n  try {\n    return new Intl.RelativeTimeFormat(locale, { numeric: num }).format(val, unit);\n  } catch(e) {\n    return 'unsupported';\n  }\n}\n\nfunction update() {\n  const val = parseInt($('valInput').value, 10);\n  const unit = $('unitSel').value;\n  if (isNaN(val)) { $('mainOut').textContent = '—'; return; }\n\n  $('mainOut').textContent = fmt(val, unit, 'en', numeric);\n  $('codeOut').textContent =\n    `const rtf = new Intl.RelativeTimeFormat('en', { numeric: '${numeric}' });\\n` +\n    `rtf.format(${val}, '${unit}');\\n\u002F\u002F → \"${fmt(val, unit, 'en', numeric)}\"`;\n\n  LOCALES.forEach(loc => {\n    const el = document.getElementById('loc-' + loc.tag);\n    if (el) el.textContent = fmt(val, unit, loc.tag, numeric);\n  });\n}\n\n$('valInput').addEventListener('input', update);\n$('unitSel').addEventListener('change', update);\n\n$('numericBtns').addEventListener('click', e => {\n  const btn = e.target.closest('[data-v]');\n  if (!btn) return;\n  numeric = btn.dataset.v;\n  $('numericBtns').querySelectorAll('.auto-chip').forEach(b => b.classList.toggle('active', b === btn));\n  update();\n});\n\n\u002F\u002F Auto-unit helper presets\nconst THRESHOLDS = [\n  { unit: 'year',   ms: 365 * 24 * 60 * 60 * 1000 },\n  { unit: 'month',  ms:  30 * 24 * 60 * 60 * 1000 },\n  { unit: 'week',   ms:   7 * 24 * 60 * 60 * 1000 },\n  { unit: 'day',    ms:       24 * 60 * 60 * 1000  },\n  { unit: 'hour',   ms:            60 * 60 * 1000  },\n  { unit: 'minute', ms:                 60 * 1000  },\n  { unit: 'second', ms:                      1000  },\n];\n\nfunction timeAgo(diffMs) {\n  for (const { unit, ms } of THRESHOLDS) {\n    if (Math.abs(diffMs) >= ms) {\n      return { unit, value: Math.round(diffMs \u002F ms) };\n    }\n  }\n  return { unit: 'second', value: 0 };\n}\n\nconst rtfAuto = new Intl.RelativeTimeFormat('en', { numeric: 'auto' });\n\nconst PRESETS = [\n  { label: '45 s ago',    ms: -45 * 1000 },\n  { label: '8 min ago',   ms: -8 * 60 * 1000 },\n  { label: '3 hrs ago',   ms: -3 * 60 * 60 * 1000 },\n  { label: 'yesterday',   ms: -1.1 * 24 * 60 * 60 * 1000 },\n  { label: '5 days ago',  ms: -5 * 24 * 60 * 60 * 1000 },\n  { label: '2 weeks ago', ms: -14 * 24 * 60 * 60 * 1000 },\n  { label: 'in 2 months', ms:  61 * 24 * 60 * 60 * 1000 },\n];\n\nconst presetsEl = $('presets');\nPRESETS.forEach((p, i) => {\n  const btn = document.createElement('button');\n  btn.className = 'auto-chip' + (i === 0 ? ' active' : '');\n  btn.textContent = p.label;\n  btn.addEventListener('click', () => {\n    presetsEl.querySelectorAll('.auto-chip').forEach(b => b.classList.remove('active'));\n    btn.classList.add('active');\n    const { unit, value } = timeAgo(p.ms);\n    const out = rtfAuto.format(value, unit);\n    $('helperOut').textContent = out;\n    $('helperCode').textContent =\n      `\u002F\u002F diffMs = ${p.ms}\\n` +\n      `const { unit, value } = pickUnit(diffMs);\\n` +\n      `\u002F\u002F → unit: \"${unit}\", value: ${value}\\n` +\n      `rtf.format(${value}, '${unit}');\\n\u002F\u002F → \"${out}\"`;\n  });\n  presetsEl.appendChild(btn);\n});\n\n\u002F\u002F Fire first preset on load\npresetsEl.querySelector('.auto-chip').click();\nupdate();",{"height":40,"autorun":17},520,{"slug":33,"title":42,"excerpt":43,"coverUrl":44},"You're installing date-fns for 'X hours ago'. `Intl.RelativeTimeFormat` does it natively.","Most apps display relative timestamps — '3 minutes ago', 'last week'. Developers still reach for date-fns or moment for this. The Intl.RelativeTimeFormat API handles it natively, with full locale support and zero dependencies.","\u002Fmedia\u002Fcovers\u002Fintl-relativetimeformat-relative-dates.png"]