[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"playground-css-style-queries-react-to-custom-properties":3,"verticals":19},{"slug":4,"title":5,"summary":6,"html":7,"css":8,"js":9,"config":10,"doc":13},"css-style-queries-react-to-custom-properties","CSS Style Queries — interactive playground",null,"\u003Cdiv class=\"pg\">\n    \u003Ch1 class=\"pg-title\">🎮 CSS Style Queries in action\u003C\u002Fh1>\n    \u003Cp class=\"pg-sub\">\n      Pick a severity below. JavaScript sets one custom property on the container —\n      then pure CSS style queries update every child element, no class toggling involved.\n    \u003C\u002Fp>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">1\u003C\u002Fspan> Choose a severity\u003C\u002Fdiv>\n      \u003Cdiv class=\"sev-grid\">\n        \u003Cbutton class=\"sev-btn active\" data-sev=\"neutral\">Neutral\u003C\u002Fbutton>\n        \u003Cbutton class=\"sev-btn\" data-sev=\"info\">Info\u003C\u002Fbutton>\n        \u003Cbutton class=\"sev-btn\" data-sev=\"success\">Success\u003C\u002Fbutton>\n        \u003Cbutton class=\"sev-btn\" data-sev=\"warning\">Warning\u003C\u002Fbutton>\n        \u003Cbutton class=\"sev-btn\" data-sev=\"error\">Error\u003C\u002Fbutton>\n      \u003C\u002Fdiv>\n      \u003Cp class=\"hint\" style=\"margin-top:10px\">\n        JS runs exactly one line: \u003Ccode>container.style.setProperty('--severity', value)\u003C\u002Fcode>.\n        Everything after that is CSS.\n      \u003C\u002Fp>\n    \u003C\u002Fdiv>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">2\u003C\u002Fspan> The alert component reacts\u003C\u002Fdiv>\n      \u003C!-- This div is the @container — JS writes --severity here -->\n      \u003Cdiv class=\"demo-root\" id=\"demoRoot\">\n        \u003Cdiv class=\"demo-alert\" role=\"alert\">\n          \u003Cspan class=\"demo-icon\" aria-hidden=\"true\">\u003C\u002Fspan>\n          \u003Cdiv>\n            \u003Cstrong class=\"demo-title\" id=\"alertTitle\">Info\u003C\u002Fstrong>\n            \u003Cp class=\"demo-msg\" id=\"alertMsg\">\n              Style queries read the \u003Ccode>--severity\u003C\u002Fcode> custom property on the container\n              ancestor and apply styles to every child — icon, title colour, background — without\n              any JavaScript touching the child elements.\n            \u003C\u002Fp>\n          \u003C\u002Fdiv>\n        \u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">3\u003C\u002Fspan> What's happening in the CSS\u003C\u002Fdiv>\n      \u003Cdiv class=\"prop-display\">\n        \u003Cspan class=\"prop-key\">.demo-root { --severity:\u003C\u002Fspan>\n        \u003Cspan class=\"prop-val\" id=\"propVal\">neutral\u003C\u002Fspan>\n        \u003Cspan class=\"prop-key\">}\u003C\u002Fspan>\n      \u003C\u002Fdiv>\n      \u003Cdiv class=\"rule-block\" id=\"ruleBlock\" aria-live=\"polite\">\u003C\u002Fdiv>\n    \u003C\u002Fdiv>\n\n    \u003Cdiv class=\"panel\">\n      \u003Cdiv class=\"panel-label\">\u003Cspan class=\"n\">4\u003C\u002Fspan> CSS vs JavaScript — the difference\u003C\u002Fdiv>\n      \u003Cdiv class=\"compare-row\">\n        \u003Cdiv class=\"compare-box\">\n          \u003Ch3>\u003Cspan class=\"badge js\">JS approach\u003C\u002Fspan> Class toggling\u003C\u002Fh3>\n\u003Cpre>\u002F\u002F JS reads state, toggles classes\nel.classList.remove('error','warning','success');\nel.classList.add(severity);\n\n\u002F\u002F CSS reacts to classes\n.alert.error   { border-color: red; }\n.alert.warning { border-color: orange; }\n.alert.success { border-color: green; }\u003C\u002Fpre>\n        \u003C\u002Fdiv>\n        \u003Cdiv class=\"compare-box\">\n          \u003Ch3>\u003Cspan class=\"badge css\">CSS approach\u003C\u002Fspan> Style queries\u003C\u002Fh3>\n\u003Cpre>\u002F\u002F JS sets ONE custom property\ncontainer.style.setProperty(\n  '--severity', value\n);\n\n\u002F\u002F CSS reads it — no class needed\n@container style(--severity: error) {\n  .alert { border-color: red; }\n}\u003C\u002Fpre>\n        \u003C\u002Fdiv>\n      \u003C\u002Fdiv>\n      \u003Cp class=\"hint\" style=\"margin-top:10px\">\n        With the CSS approach, adding a new child element means one new\n        \u003Ccode>@container style()\u003C\u002Fcode> rule — you never touch the JavaScript.\n      \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* ── severity buttons ── *\u002F\n  .sev-grid {\n    display: grid;\n    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));\n    gap: 8px;\n  }\n  .sev-btn {\n    padding: 10px 14px;\n    border-radius: var(--radius-sm);\n    border: 2px solid var(--line);\n    background: var(--panel-2);\n    cursor: pointer;\n    font-size: .82rem;\n    font-weight: 600;\n    transition: border-color .15s, background .15s, transform .1s;\n    text-align: center;\n  }\n  .sev-btn:hover { border-color: var(--accent); }\n  .sev-btn.active { border-color: var(--accent); background: var(--accent); color: #fff; }\n  .sev-btn:active { transform: scale(.96); }\n\n  \u002F* ── the demo container (this is the CSS @container) ── *\u002F\n  .demo-root {\n    container-type: inline-size;\n    container-name: alert-demo;\n    --severity: neutral;\n    padding: 4px 0;\n  }\n\n  \u002F* ── alert card base ── *\u002F\n  .demo-alert {\n    display: flex;\n    gap: 14px;\n    align-items: flex-start;\n    padding: 16px 18px;\n    border-radius: var(--radius);\n    border: 2px solid var(--line);\n    background: var(--panel-2);\n    color: var(--fg);\n    transition: border-color .3s, background .3s, color .3s;\n  }\n  .demo-icon {\n    font-size: 1.5rem;\n    line-height: 1;\n    flex-shrink: 0;\n    margin-top: 2px;\n    min-width: 1.5rem;\n    text-align: center;\n  }\n  .demo-title {\n    display: block;\n    font-weight: 700;\n    margin-bottom: 4px;\n    font-size: .95rem;\n    transition: color .3s;\n  }\n  .demo-msg {\n    font-size: .82rem;\n    color: var(--muted);\n    margin: 0;\n    transition: color .3s;\n  }\n\n  \u002F* ── style queries: each severity sets colours + icon ── *\u002F\n  @container alert-demo style(--severity: neutral) {\n    .demo-alert { border-color: var(--line); background: var(--panel-2); }\n    .demo-icon::before { content: \"ℹ️\"; }\n    .demo-title { color: var(--fg); }\n  }\n  @container alert-demo style(--severity: error) {\n    .demo-alert { border-color: #ef4444; background: #ef444418; }\n    .demo-icon::before { content: \"⛔\"; }\n    .demo-title { color: #ef4444; }\n  }\n  @container alert-demo style(--severity: warning) {\n    .demo-alert { border-color: #f59e0b; background: #f59e0b18; }\n    .demo-icon::before { content: \"⚠️\"; }\n    .demo-title { color: #d97706; }\n  }\n  @container alert-demo style(--severity: success) {\n    .demo-alert { border-color: #22c55e; background: #22c55e18; }\n    .demo-icon::before { content: \"✅\"; }\n    .demo-title { color: #16a34a; }\n  }\n  @container alert-demo style(--severity: info) {\n    .demo-alert { border-color: #3b82f6; background: #3b82f618; }\n    .demo-icon::before { content: \"💡\"; }\n    .demo-title { color: #2563eb; }\n  }\n\n  \u002F* ── code display ── *\u002F\n  .prop-display {\n    display: flex;\n    align-items: center;\n    gap: 10px;\n    flex-wrap: wrap;\n    font-family: var(--mono);\n    font-size: .78rem;\n    padding: 10px 14px;\n    background: var(--panel-2);\n    border-radius: var(--radius-sm);\n    border: 1px solid var(--line);\n  }\n  .prop-key { color: var(--muted); }\n  .prop-val { font-weight: 700; color: var(--accent); }\n  .prop-arrow { color: var(--muted); }\n\n  .rule-block {\n    margin-top: 8px;\n    padding: 12px 14px;\n    background: var(--panel-2);\n    border-radius: var(--radius-sm);\n    border: 1px solid var(--line);\n    font-family: var(--mono);\n    font-size: .77rem;\n    line-height: 1.6;\n    white-space: pre;\n    overflow-x: auto;\n  }\n  .css-at  { color: #c084fc; }\n  .css-sel { color: #60a5fa; }\n  .css-prop { color: #4ade80; }\n  .css-val  { color: #fb923c; }\n\n  \u002F* ── second demo: comparison panel ── *\u002F\n  .compare-row {\n    display: grid;\n    grid-template-columns: 1fr 1fr;\n    gap: 12px;\n  }\n  @media (max-width: 520px) { .compare-row { grid-template-columns: 1fr; } }\n\n  .compare-box {\n    padding: 14px;\n    border-radius: var(--radius-sm);\n    border: 1px solid var(--line);\n    background: var(--panel-2);\n    font-size: .78rem;\n  }\n  .compare-box h3 {\n    font-size: .82rem;\n    margin: 0 0 8px;\n    padding-bottom: 6px;\n    border-bottom: 1px solid var(--line);\n    display: flex;\n    align-items: center;\n    gap: 6px;\n  }\n  .badge {\n    font-size: .65rem;\n    padding: 2px 6px;\n    border-radius: 4px;\n    font-weight: 700;\n  }\n  .badge.js  { background: #f59e0b33; color: #f59e0b; border: 1px solid #f59e0b55; }\n  .badge.css { background: #3b82f633; color: #60a5fa; border: 1px solid #3b82f655; }\n  .compare-box pre {\n    margin: 0;\n    font-family: var(--mono);\n    font-size: .72rem;\n    white-space: pre-wrap;\n    word-break: break-word;\n    color: var(--fg);\n    line-height: 1.55;\n  }","\"use strict\";\n\nconst root = document.getElementById('demoRoot');\nconst propVal = document.getElementById('propVal');\nconst ruleBlock = document.getElementById('ruleBlock');\nconst alertTitle = document.getElementById('alertTitle');\nconst alertMsg = document.getElementById('alertMsg');\n\nconst CONFIG = {\n  neutral: {\n    title: 'Neutral',\n    msg: 'The container has --severity: neutral. The @container style(--severity: neutral) rule applies — default colours and the ℹ️ icon.',\n    rule: `@container alert-demo style(--severity: neutral) {\\n  .demo-alert  { border-color: var(--line); }\\n  .demo-icon::before { content: \"ℹ️\"; }\\n  .demo-title  { color: var(--fg); }\\n}`\n  },\n  info: {\n    title: 'Info',\n    msg: 'The container has --severity: info. The @container style(--severity: info) rule applies — blue tones and the 💡 icon.',\n    rule: `@container alert-demo style(--severity: info) {\\n  .demo-alert  { border-color: #3b82f6; background: #3b82f618; }\\n  .demo-icon::before { content: \"💡\"; }\\n  .demo-title  { color: #2563eb; }\\n}`\n  },\n  success: {\n    title: 'Success',\n    msg: 'The container has --severity: success. The @container style(--severity: success) rule applies — green tones and the ✅ icon.',\n    rule: `@container alert-demo style(--severity: success) {\\n  .demo-alert  { border-color: #22c55e; background: #22c55e18; }\\n  .demo-icon::before { content: \"✅\"; }\\n  .demo-title  { color: #16a34a; }\\n}`\n  },\n  warning: {\n    title: 'Warning',\n    msg: 'The container has --severity: warning. The @container style(--severity: warning) rule applies — amber tones and the ⚠️ icon.',\n    rule: `@container alert-demo style(--severity: warning) {\\n  .demo-alert  { border-color: #f59e0b; background: #f59e0b18; }\\n  .demo-icon::before { content: \"⚠️\"; }\\n  .demo-title  { color: #d97706; }\\n}`\n  },\n  error: {\n    title: 'Error',\n    msg: 'The container has --severity: error. The @container style(--severity: error) rule applies — red tones and the ⛔ icon.',\n    rule: `@container alert-demo style(--severity: error) {\\n  .demo-alert  { border-color: #ef4444; background: #ef444418; }\\n  .demo-icon::before { content: \"⛔\"; }\\n  .demo-title  { color: #ef4444; }\\n}`\n  }\n};\n\nfunction setSeverity(sev) {\n  \u002F\u002F The only JavaScript that touches the component: one custom property\n  root.style.setProperty('--severity', sev);\n\n  const cfg = CONFIG[sev];\n  propVal.textContent = sev;\n  alertTitle.textContent = cfg.title;\n  alertMsg.textContent = cfg.msg;\n  ruleBlock.textContent = cfg.rule;\n\n  document.querySelectorAll('.sev-btn').forEach(btn => {\n    btn.classList.toggle('active', btn.dataset.sev === sev);\n  });\n}\n\ndocument.querySelectorAll('.sev-btn').forEach(btn => {\n  btn.addEventListener('click', () => setSeverity(btn.dataset.sev));\n});\n\n\u002F\u002F Check browser support\nif (!CSS.supports('container-type', 'inline-size')) {\n  const warn = document.createElement('div');\n  warn.className = 'status';\n  warn.innerHTML = '\u003Cspan class=\"dot warn\">\u003C\u002Fspan> Your browser may not support container style queries. Try Chrome 111+, Firefox 110+, or Safari 17.2+.';\n  document.querySelector('.pg').prepend(warn);\n}\n\nsetSeverity('neutral');",{"height":11,"autorun":12},520,true,{"slug":4,"title":14,"excerpt":15,"coverUrl":16,"vertical":17},"Container queries can check more than size — style queries let components read custom property values","Size queries react to container width. Style queries react to CSS custom property values on a container ancestor — enabling component-level theming and variant switching in pure CSS, no JavaScript involved.","\u002Fmedia\u002Fcovers\u002Fcss-style-queries-react-to-custom-properties.png",{"slug":18},"dev",[20,34],{"id":21,"slug":18,"name":22,"tagline":23,"description":24,"accentFrom":25,"accentTo":26,"icon":27,"defaultLocale":28,"locales":29,"features":31,"position":33},"019fe637-3d33-714b-b57f-23e163ffca0c","Web Development","Build. Learn. Ship.","Practical courses, engineering-grade articles and open-source tools for people who ship.","violet-500","cyan-400","◇","en",[28,30],"fa",{"courses":12,"paths":12,"articles":12,"exams":32,"flashcards":32,"packages":12,"community":12,"certificates":12,"teams":12,"commerce":12},false,0,{"id":35,"slug":36,"name":37,"tagline":38,"description":39,"accentFrom":40,"accentTo":25,"icon":41,"defaultLocale":28,"locales":42,"features":44,"position":45},"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","⌘",[28,30,43],"es",{"courses":32,"paths":32,"articles":12,"exams":32,"flashcards":12,"packages":32,"community":12,"certificates":12,"teams":32,"commerce":32},2]