[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"verticals":3,"playground-spanish-a1-ser-vs-estar":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":18,"paths":18,"articles":17,"exams":18,"flashcards":17,"packages":18,"community":17,"certificates":17,"teams":18,"commerce":18},2,{"slug":33,"title":34,"summary":35,"html":36,"css":37,"js":38,"config":39,"doc":41},"spanish-a1-ser-vs-estar","Spanish A1: ser vs estar — two verbs for 'to be', and the line between them",null,"\u003Cdiv class=\"pg\">\n      \u003Ch1 class=\"pg-title\">🎯 ser o estar\u003C\u002Fh1>\n      \u003Cp class=\"pg-sub\">Choose the verb. Ask: am I saying what it is, or how it is right now?\u003C\u002Fp>\n\n      \u003Cdiv class=\"panel\">\n        \u003Cdiv class=\"scoreline\">\n          \u003Cspan id=\"progress\">1 \u002F 1\u003C\u002Fspan>\n          \u003Cspan id=\"score\">0 correct\u003C\u002Fspan>\n        \u003C\u002Fdiv>\n        \u003Cdiv class=\"bar\">\u003Ci id=\"bar\">\u003C\u002Fi>\u003C\u002Fdiv>\n\n        \u003Cdiv id=\"stage\">\n          \u003Cp class=\"prompt\" id=\"prompt\">\u003C\u002Fp>\n          \u003Cp class=\"gloss\" id=\"gloss\">\u003C\u002Fp>\n          \u003Cdiv class=\"choices\" id=\"choices\">\u003C\u002Fdiv>\n          \u003Cp class=\"verdict\" id=\"verdict\">\u003C\u002Fp>\n        \u003C\u002Fdiv>\n\n        \u003Cdiv class=\"seg\" style=\"margin-top: 4px\">\n          \u003Cbutton id=\"again\" hidden>Play again\u003C\u002Fbutton>\n        \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.prompt {\n        font-size: 1.35rem;\n        line-height: 1.5;\n        font-weight: 600;\n        text-align: center;\n        margin: 18px 0 4px;\n      }\n      .prompt .gap {\n        display: inline-block;\n        min-width: 5.5em;\n        border-bottom: 2px dashed var(--accent, #8b5cf6);\n        margin: 0 4px;\n      }\n      .prompt .gap.filled {\n        border-bottom-style: solid;\n        color: var(--accent, #a78bfa);\n      }\n      .gloss {\n        text-align: center;\n        font-size: 0.9rem;\n        opacity: 0.7;\n        margin: 0 0 14px;\n      }\n      .choices {\n        display: grid;\n        grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));\n        gap: 8px;\n      }\n      .choice {\n        padding: 13px 10px;\n        font-size: 0.98rem;\n        cursor: pointer;\n        text-align: center;\n      }\n      .choice.right {\n        border-color: #34d399;\n        background: rgba(52, 211, 153, 0.12);\n        color: #34d399;\n      }\n      .choice.wrong {\n        border-color: #fb7185;\n        background: rgba(251, 113, 133, 0.12);\n        color: #fb7185;\n      }\n      .choice[disabled] {\n        cursor: default;\n      }\n      .verdict {\n        min-height: 3.4em;\n        margin-top: 12px;\n        font-size: 0.9rem;\n        line-height: 1.55;\n      }\n      .scoreline {\n        display: flex;\n        justify-content: space-between;\n        font-family: var(--mono, monospace);\n        font-size: 0.78rem;\n        opacity: 0.75;\n      }\n      .bar {\n        height: 4px;\n        border-radius: 999px;\n        background: var(--surface-2, #222);\n        overflow: hidden;\n        margin-top: 6px;\n      }\n      .bar i {\n        display: block;\n        height: 100%;\n        width: 0;\n        background: linear-gradient(90deg, #8b5cf6, #22d3ee);\n        transition: width 0.25s;\n      }\n      .final {\n        text-align: center;\n        padding: 10px 0 4px;\n      }\n      .final .big {\n        font-size: 2.4rem;\n        font-weight: 700;\n      }\n      .missed {\n        margin-top: 14px;\n        text-align: left;\n        font-size: 0.86rem;\n        line-height: 1.6;\n      }\n      .missed li {\n        margin-bottom: 6px;\n      }","\u002F**\n       * A gap-fill drill.\n       *\n       * The lesson supplies items; this supplies the loop. Each item is a\n       * sentence with __ where the answer goes, the choices, and — the part\n       * that matters — why the right answer is right, shown whether you got it\n       * or not, because being told only when you are wrong teaches you to fear\n       * the button rather than understand the rule.\n       *\u002F\n      const DATA = {\n  \"items\": [\n    {\n      \"sentence\": \"Ana __ profesora.\",\n      \"gloss\": \"Ana is a teacher.\",\n      \"options\": [\n        \"es\",\n        \"está\"\n      ],\n      \"answer\": \"es\",\n      \"why\": \"Identity — what she \u003Cb>is\u003C\u002Fb>. That is always \u003Cb>ser\u003C\u002Fb>.\"\n    },\n    {\n      \"sentence\": \"__ cansado hoy.\",\n      \"gloss\": \"I'm tired today.\",\n      \"options\": [\n        \"Estoy\",\n        \"Soy\"\n      ],\n      \"answer\": \"Estoy\",\n      \"why\": \"A physical state — how you are right now. \u003Cb>estar\u003C\u002Fb>.\"\n    },\n    {\n      \"sentence\": \"El libro __ en la mesa.\",\n      \"gloss\": \"The book is on the table.\",\n      \"options\": [\n        \"está\",\n        \"es\"\n      ],\n      \"answer\": \"está\",\n      \"why\": \"Location of a thing is always \u003Cb>estar\u003C\u002Fb>.\"\n    },\n    {\n      \"sentence\": \"La fiesta __ en mi casa.\",\n      \"gloss\": \"The party is at my house.\",\n      \"options\": [\n        \"es\",\n        \"está\"\n      ],\n      \"answer\": \"es\",\n      \"why\": \"An event \u003Ci>takes place\u003C\u002Fi> — that is \u003Cb>ser\u003C\u002Fb>, even though it looks like location.\"\n    },\n    {\n      \"sentence\": \"__ las tres de la tarde.\",\n      \"gloss\": \"It's three in the afternoon.\",\n      \"options\": [\n        \"Son\",\n        \"Están\"\n      ],\n      \"answer\": \"Son\",\n      \"why\": \"Time is always \u003Cb>ser\u003C\u002Fb>.\"\n    },\n    {\n      \"sentence\": \"Este café __ rico.\",\n      \"gloss\": \"This coffee tastes great.\",\n      \"options\": [\n        \"está\",\n        \"es\"\n      ],\n      \"answer\": \"está\",\n      \"why\": \"With \u003Cb>estar\u003C\u002Fb>, rico means delicious. With ser it would mean wealthy.\"\n    },\n    {\n      \"sentence\": \"La puerta __ abierta.\",\n      \"gloss\": \"The door is open.\",\n      \"options\": [\n        \"está\",\n        \"es\"\n      ],\n      \"answer\": \"está\",\n      \"why\": \"The result of a change — someone opened it. \u003Cb>estar\u003C\u002Fb>.\"\n    },\n    {\n      \"sentence\": \"La mesa __ de madera.\",\n      \"gloss\": \"The table is wooden.\",\n      \"options\": [\n        \"es\",\n        \"está\"\n      ],\n      \"answer\": \"es\",\n      \"why\": \"Material is part of what it is. \u003Cb>ser\u003C\u002Fb>.\"\n    },\n    {\n      \"sentence\": \"__ comiendo ahora mismo.\",\n      \"gloss\": \"I'm eating right now.\",\n      \"options\": [\n        \"Estoy\",\n        \"Soy\"\n      ],\n      \"answer\": \"Estoy\",\n      \"why\": \"Progressive tenses always take \u003Cb>estar\u003C\u002Fb>.\"\n    },\n    {\n      \"sentence\": \"El gazpacho __ frío.\",\n      \"gloss\": \"Gazpacho is a cold soup.\",\n      \"options\": [\n        \"es\",\n        \"está\"\n      ],\n      \"answer\": \"es\",\n      \"why\": \"By definition, not by temperature today — \u003Cb>ser\u003C\u002Fb>. \u003Ci>Está frío\u003C\u002Fi> would mean it has gone cold.\"\n    },\n    {\n      \"sentence\": \"Mis padres __ de Sevilla.\",\n      \"gloss\": \"My parents are from Seville.\",\n      \"options\": [\n        \"son\",\n        \"están\"\n      ],\n      \"answer\": \"son\",\n      \"why\": \"Origin is \u003Cb>ser\u003C\u002Fb>. \u003Ci>Están en Sevilla\u003C\u002Fi> would mean they are there now.\"\n    },\n    {\n      \"sentence\": \"El niño __ aburrido en clase.\",\n      \"gloss\": \"The boy is bored in class.\",\n      \"options\": [\n        \"está\",\n        \"es\"\n      ],\n      \"answer\": \"está\",\n      \"why\": \"\u003Cb>estar aburrido\u003C\u002Fb> = bored. \u003Ci>Es aburrido\u003C\u002Fi> would call him boring.\"\n    }\n  ]\n};\n\n      const $ = (id) => document.getElementById(id);\n      const shuffle = (a) => a.map((v) => [Math.random(), v]).sort((x, y) => x[0] - y[0]).map((p) => p[1]);\n\n      let deck = [];\n      let index = 0;\n      let score = 0;\n      let locked = false;\n      let missed = [];\n\n      function start() {\n        deck = shuffle([...DATA.items]);\n        index = 0;\n        score = 0;\n        missed = [];\n        $('again').hidden = true;\n        $('stage').hidden = false;\n        render();\n      }\n\n      function sentence(item, filledWith) {\n        const gap = filledWith\n          ? `\u003Cspan class=\"gap filled\">${filledWith}\u003C\u002Fspan>`\n          : '\u003Cspan class=\"gap\">\u003C\u002Fspan>';\n        return item.sentence.replace('__', gap);\n      }\n\n      function render() {\n        locked = false;\n        const item = deck[index];\n\n        $('progress').textContent = `${index + 1} \u002F ${deck.length}`;\n        $('score').textContent = `${score} correct`;\n        $('bar').style.width = `${(index \u002F deck.length) * 100}%`;\n        $('prompt').innerHTML = sentence(item);\n        $('gloss').textContent = item.gloss ?? '';\n        $('verdict').textContent = '';\n\n        $('choices').innerHTML = shuffle([...item.options])\n          .map((o) => `\u003Cbutton class=\"btn choice\" data-value=\"${o}\">${o}\u003C\u002Fbutton>`)\n          .join('');\n\n        for (const button of $('choices').querySelectorAll('.choice')) {\n          button.addEventListener('click', () => check(button, item));\n        }\n      }\n\n      function check(button, item) {\n        if (locked) return;\n        locked = true;\n\n        const chosen = button.dataset.value;\n        const correct = chosen === item.answer;\n        if (correct) score++;\n        else missed.push(item);\n\n        for (const other of $('choices').querySelectorAll('.choice')) {\n          other.disabled = true;\n          if (other.dataset.value === item.answer) other.classList.add('right');\n          else if (other === button) other.classList.add('wrong');\n        }\n\n        $('prompt').innerHTML = sentence(item, item.answer);\n        $('score').textContent = `${score} correct`;\n        $('verdict').innerHTML = `${correct ? '✅' : '❌'} ${item.why}`;\n\n        setTimeout(() => {\n          index++;\n          if (index \u003C deck.length) render();\n          else finish();\n        }, correct ? 1500 : 3000);\n      }\n\n      function finish() {\n        $('bar').style.width = '100%';\n        $('progress').textContent = 'done';\n        $('stage').hidden = true;\n\n        const perfect = score === deck.length;\n        const list = missed.length\n          ? `\u003Cul class=\"missed\">${missed\n              .map((m) => `\u003Cli>${sentence(m, m.answer)} — ${m.why}\u003C\u002Fli>`)\n              .join('')}\u003C\u002Ful>`\n          : '';\n\n        $('stage').insertAdjacentHTML(\n          'afterend',\n          `\u003Cdiv class=\"final\" id=\"final\">\n             \u003Cdiv class=\"big\">${score} \u002F ${deck.length}\u003C\u002Fdiv>\n             \u003Cp class=\"gloss\">${\n               perfect\n                 ? 'All of them. You have the rule, not just the examples.'\n                 : 'The ones that got away:'\n             }\u003C\u002Fp>\n             ${list}\n           \u003C\u002Fdiv>`,\n        );\n        $('again').hidden = false;\n      }\n\n      $('again').addEventListener('click', () => {\n        document.getElementById('final')?.remove();\n        start();\n      });\n\n      start();",{"height":40,"autorun":17},520,{"slug":33,"title":34,"excerpt":42,"coverUrl":35,"vertical":43},"Spanish splits 'to be' into ser and estar. The usual advice — permanent versus temporary — breaks immediately. Here is the line that actually holds.",{"slug":22}]