Animated Gapminder

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<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Animated Gapminder — sloprun.dev</title>
<style>
/* ── sloprun design tokens (verbatim from demos/tokens.css) ───────────────── */
/* sloprun design tokens — inline this block into every demo (self-contained rule).
   Identity: instrument-panel. Machine facts in mono; human words in sans.
   Green is EARNED: only for "it ran / it worked" states, never decoration. */
:root {
  --bg: #F6F6F3;          /* neutral paper, not cream */
  --surface: #FFFFFF;
  --ink: #1A1D21;
  --muted: #5A6068;
  --line: #E3E2DC;
  --accent: #C05600;      /* phosphor amber, darkened for light bg */
  --accent-soft: #FFF3E6;
  --run: #1A7F37;         /* earned green */
  --run-soft: #E7F4EA;
  --danger: #C93C37;
  --radius: 10px;
  --font-sans: system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #14161A; --surface: #1C1F26; --ink: #E8E6E1; --muted: #9AA0A8;
    --line: #2A2E36; --accent: #FFB454; --accent-soft: #2A2118;
    --run: #3FB950; --run-soft: #16281B; --danger: #F47067;
  }
}
:root[data-theme="dark"] {
  --bg: #14161A; --surface: #1C1F26; --ink: #E8E6E1; --muted: #9AA0A8;
  --line: #2A2E36; --accent: #FFB454; --accent-soft: #2A2118;
  --run: #3FB950; --run-soft: #16281B; --danger: #F47067;
}
body { background: var(--bg); color: var(--ink); font-family: var(--font-sans); }

/* ── region palette ───────────────────────────────────────────────────────────
   Four Gapminder world regions. A bubble chart puts every mark on screen at once,
   so adjacency is not enough — these are validated all-pairs AND each colour is
   checked against the plot field it is drawn on (WCAG 1.4.11 non-text contrast,
   3:1 floor: the full-alpha bubble outline is what carries the mark boundary).
     light on --field #FBFBF9   eu 4.3 · af 3.7 · am 4.2 · as 6.1
     dark  on --field #171A20   eu 4.8 · af 5.7 · am 4.4 · as 3.5
     worst pair, ΔE76 in Lab    light 70 normal / 31 deuteranopia
                                dark  73 normal / 25 deuteranopia
   The light amber and magenta are deliberately darker than their dark-theme twins
   — on near-white the earlier #eda100 / #e87ba4 measured 2.1:1 and 2.6:1 and the
   bubbles washed out. Identity still never rests on hue alone: a persistent
   legend, direct labels drawn on every large bubble, the hover/selection readout
   and the full numbers table all name the country and its region in words. ---- */
:root {
  --r-eu: #2a78d6;  /* Europe        — blue    */
  --r-af: #B67500;  /* Africa        — amber   */
  --r-am: #D2417B;  /* Americas      — magenta */
  --r-as: #00701F;  /* Asia & Oceania— green   */
  --field: #FBFBF9;
  --accent-ink: #A34700;  /* accent for TEXT: --accent is only 4.20:1 on --accent-soft */
  --shadow: 0 6px 22px rgba(0,0,0,.16);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --r-eu: #3987e5; --r-af: #c98500; --r-am: #d55181; --r-as: #008300;
    --field: #171A20; --accent-ink: #FFB454;
    --shadow: 0 8px 26px rgba(0,0,0,.62);
  }
}
:root[data-theme="dark"] {
  --r-eu: #3987e5; --r-af: #c98500; --r-am: #d55181; --r-as: #008300;
  --field: #171A20; --accent-ink: #FFB454;
  --shadow: 0 8px 26px rgba(0,0,0,.62);
}

/* ── shell ────────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; padding: 18px 14px 26px; line-height: 1.5; font-size: 15px;
  overflow-x: hidden;
}
.wrap { max-width: 1060px; margin: 0 auto; display: grid; gap: 14px; }

header .kicker {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: .09em;
  text-transform: uppercase; color: var(--muted); margin: 0 0 6px;
}
h1 { font-size: clamp(22px, 5.2vw, 30px); line-height: 1.15; margin: 0 0 7px; letter-spacing: -.015em; }
.lede { margin: 0; color: var(--muted); max-width: 68ch; font-size: clamp(13.5px, 3.3vw, 15px); }
.lede b { color: var(--ink); font-weight: 600; }

.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 12px; min-width: 0;
}

/* ── transport bar ────────────────────────────────────────────────────────── */
.transport { display: grid; gap: 10px; grid-template-columns: 1fr; }
.tline { display: flex; align-items: center; gap: 10px; min-width: 0; flex-wrap: wrap; }
.year {
  font-family: var(--font-mono); font-size: clamp(26px, 7.4vw, 38px);
  font-weight: 600; letter-spacing: -.02em; line-height: 1;
  font-variant-numeric: tabular-nums; color: var(--ink); flex: none;
  min-width: 4.2ch; text-align: right;
}
.scrub { flex: 1 1 210px; min-width: 0; display: grid; gap: 3px; }
.scrub-ends {
  display: flex; justify-content: space-between;
  font-family: var(--font-mono); font-size: 10px; letter-spacing: .07em; color: var(--muted);
}
input[type=range] {
  width: 100%; margin: 0; accent-color: var(--accent);
  background: transparent; cursor: pointer; height: 26px;
}
input[type=range]:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px; }

button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 5px; }
.btn {
  background: var(--surface); border: 1px solid var(--line); color: var(--ink);
  border-radius: 8px; padding: 7px 11px; cursor: pointer; white-space: nowrap;
  font-family: var(--font-mono); font-size: 12.5px; line-height: 1.35;
  display: inline-flex; align-items: center; gap: 6px;
}
.btn:hover { border-color: var(--accent); background: var(--accent-soft); }
.btn[aria-pressed="true"] { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-ink); }
.btn.play {
  background: var(--accent); border-color: var(--accent); color: var(--surface);
  font-weight: 600; min-width: 92px; justify-content: center; padding: 9px 12px;
}
.btn.play:hover { filter: brightness(1.07); }
.glyph { font-size: 11px; line-height: 1; }

.seg { position: relative; display: inline-flex; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; background: var(--field); flex: none; }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg label {
  padding: 6px 9px; font-family: var(--font-mono); font-size: 12px; cursor: pointer;
  color: var(--muted); border-right: 1px solid var(--line); user-select: none; white-space: nowrap;
}
.seg label:last-of-type { border-right: 0; }
.seg label:hover { color: var(--ink); background: var(--accent-soft); }
.seg input:checked + label { background: var(--accent-soft); color: var(--accent-ink); font-weight: 600; }
.seg input:focus-visible + label { outline: 2px solid var(--accent); outline-offset: -2px; }
.seg-cap {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: .07em;
  text-transform: uppercase; color: var(--muted); margin-right: 2px; flex: none;
}
.tline.opts { flex-wrap: wrap; gap: 8px; }
.spacer { flex: 1 1 auto; }

/* ── plot ─────────────────────────────────────────────────────────────────── */
.plotwrap { position: relative; }
canvas { display: block; width: 100%; height: auto; border-radius: 6px; touch-action: pan-y; }
canvas:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.tip {
  position: absolute; z-index: 5; pointer-events: none; opacity: 0;
  transform: translate(-50%, -100%); transition: opacity .12s ease;
  background: var(--surface); border: 1px solid var(--line); border-radius: 8px;
  padding: 8px 10px; min-width: 168px; box-shadow: var(--shadow);
}
.tip.on { opacity: 1; }
.tip .tname { font-size: 13.5px; font-weight: 600; display: flex; align-items: center; gap: 7px; }
.tip .sw { width: 9px; height: 9px; border-radius: 50%; flex: none; }
.tip .treg { font-family: var(--font-mono); font-size: 10px; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); margin: 2px 0 6px 16px; }
.tip dl { margin: 0; display: grid; grid-template-columns: auto auto; gap: 2px 12px; }
.tip dt { font-family: var(--font-mono); font-size: 10px; letter-spacing: .05em; text-transform: uppercase; color: var(--muted); }
.tip dd { margin: 0; font-family: var(--font-mono); font-size: 12.5px; text-align: right; font-variant-numeric: tabular-nums; }

/* ── legend ───────────────────────────────────────────────────────────────── */
.legend { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; margin-top: 10px; }
.lg {
  display: inline-flex; align-items: center; gap: 6px; cursor: pointer;
  border: 1px solid var(--line); background: var(--field); border-radius: 999px;
  padding: 4px 10px 4px 7px; font-family: var(--font-mono); font-size: 11.5px; color: var(--ink);
}
.lg:hover { border-color: var(--accent); }
.lg .sw { width: 10px; height: 10px; border-radius: 50%; flex: none; }
.lg[aria-pressed="false"] { color: var(--muted); border-style: dashed; }
.lg[aria-pressed="false"] .sw {
  background: transparent !important; box-shadow: inset 0 0 0 1.5px var(--muted);
}
.lg .off { display: none; }
.lg[aria-pressed="false"] .off { display: inline; }
.sizekey {
  display: inline-flex; align-items: center; gap: 6px; margin-left: auto;
  font-family: var(--font-mono); font-size: 10px; letter-spacing: .05em;
  text-transform: uppercase; color: var(--muted);
}
.sizekey i { display: inline-block; border-radius: 50%; border: 1.5px solid var(--muted); opacity: .8; }
.sizekey i.a { width: 7px; height: 7px; }
.sizekey i.b { width: 15px; height: 15px; }

/* ── caption ──────────────────────────────────────────────────────────────── */
.caption {
  display: grid; grid-template-columns: auto 1fr; gap: 10px; align-items: start;
  border-left: 3px solid var(--accent); background: var(--accent-soft);
  border-radius: 0 8px 8px 0; padding: 9px 12px; margin-top: 10px;
}
.caption .span {
  font-family: var(--font-mono); font-size: 11px; color: var(--accent-ink);
  letter-spacing: .04em; white-space: nowrap; padding-top: 2px; font-weight: 600;
}
.caption p { margin: 0; font-size: 13.5px; color: var(--ink); }

/* ── stat tiles ───────────────────────────────────────────────────────────── */
.stats { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 10px; }
.tile { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 10px 12px; min-width: 0; }
.tile .k {
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: .08em;
  text-transform: uppercase; color: var(--muted); display: block; margin-bottom: 4px;
}
.tile .v {
  font-family: var(--font-mono); font-size: clamp(17px, 4.6vw, 22px); font-weight: 600;
  font-variant-numeric: tabular-nums; display: block; line-height: 1.1; letter-spacing: -.01em;
}
.tile .n { font-family: var(--font-sans); font-size: 11.5px; color: var(--muted); display: block; margin-top: 3px; }

/* ── table ────────────────────────────────────────────────────────────────── */
.tablehead { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
h2 {
  font-family: var(--font-mono); font-size: 11.5px; font-weight: 600; margin: 0;
  letter-spacing: .07em; text-transform: uppercase; color: var(--muted);
}
.tscroll { overflow-x: auto; margin-top: 10px; }
table { border-collapse: collapse; width: 100%; min-width: 460px; font-size: 13px; }
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<div class="wrap">

  <header>
    <p class="kicker">dataviz · 14 countries · 1900 → 2020</p>
    <h1>Animated Gapminder</h1>
    <p class="lede">
      Every bubble is a country: <b>income to the right</b>, <b>lifespan upward</b>,
      <b>size is population</b>. Press play and 120 years go by in ten seconds.
    </p>
  </header>

  <section class="card transport" aria-label="Playback">
    <div class="tline">
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      <span class="year" id="yearOut">1900</span>
      <div class="scrub">
        <input type="range" id="scrub" min="1900" max="2020" step="1" value="1900"
               aria-label="Year">
        <span class="scrub-ends"><span>1900</span><span>1960</span><span>2020</span></span>
      </div>
    </div>
    <div class="tline opts">
      <span class="seg-cap">speed</span>
      <div class="seg" role="radiogroup" aria-label="Playback speed">
        <input type="radio" name="spd" id="spd05" value="0.5"><label for="spd05">0.5×</label>
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      </div>
      <button class="btn" id="trails" type="button" aria-pressed="false">Trails</button>
      <button class="btn" id="rewind" type="button"><span class="glyph" aria-hidden="true">⟲</span>1900</button>
      <span class="spacer"></span>
      <button class="btn" id="tableBtn" type="button" aria-pressed="false" aria-controls="tablecard">Numbers</button>
    </div>
  </section>

  <section class="card" aria-label="Chart">
    <div class="plotwrap" id="plotwrap">
      <canvas id="c" tabindex="0" role="img" aria-label="Bubble chart of life expectancy against income for 14 countries."></canvas>
      <div class="tip" id="tip" aria-hidden="true">
        <div class="tname"><span class="sw" id="tipSw"></span><span id="tipName">—</span></div>
        <div class="treg" id="tipReg">—</div>
        <dl>
          <dt>income</dt><dd id="tipGdp">—</dd>
          <dt>life exp</dt><dd id="tipLe">—</dd>
          <dt>people</dt><dd id="tipPop">—</dd>
        </dl>
      </div>
    </div>

    <div class="legend" id="legend" role="group" aria-label="Filter by region">
      <button class="lg" type="button" data-r="Europe" aria-pressed="true"><span class="sw" style="background:var(--r-eu)"></span>Europe<span class="off">&nbsp;· off</span></button>
      <button class="lg" type="button" data-r="Americas" aria-pressed="true"><span class="sw" style="background:var(--r-am)"></span>Americas<span class="off">&nbsp;· off</span></button>
      <button class="lg" type="button" data-r="Africa" aria-pressed="true"><span class="sw" style="background:var(--r-af)"></span>Africa<span class="off">&nbsp;· off</span></button>
      <button class="lg" type="button" data-r="Asia &amp; Oceania" aria-pressed="true"><span class="sw" style="background:var(--r-as)"></span>Asia &amp; Oceania<span class="off">&nbsp;· off</span></button>
      <span class="sizekey"><i class="a"></i><i class="b"></i>&nbsp;bubble = population</span>
    </div>

    <div class="caption">
      <span class="span" id="capSpan">1900–13</span>
      <p id="capText">Most of humanity lives under 40 years. Only the industrial west has crossed 50.</p>
    </div>

    <p class="sr-only" id="canvasHelp">
      Chart keyboard controls: left and right arrows step one year, hold Shift for ten years,
      up and down arrows move between countries, Enter or Space plays and pauses.
      The Numbers button below opens the same data as a table.
    </p>
  </section>

  <section class="stats" aria-label="Summary for the current year">
    <div class="tile"><span class="k">life expectancy · mean</span><span class="v" id="stLe">32.6 yrs</span><span class="n" id="stLeN">across 1.03 bn people</span></div>
    <div class="tile"><span class="k">income · median</span><span class="v" id="stGdp">$1,900</span><span class="n">GDP per person, 2011 $</span></div>
    <div class="tile"><span class="k">richest ÷ poorest</span><span class="v" id="stGap">10.0×</span><span class="n" id="stGapN">$8,000 vs $800</span></div>
  </section>

  <section class="card" id="tablecard" hidden aria-label="Numbers">
    <div class="tablehead">
      <h2>Values in <span id="tblYear">1900</span></h2>
      <span class="spacer"></span>
      <span class="seg-cap" id="tblCount">14 countries</span>
    </div>
    <div class="tscroll">
      <table>
        <thead>
          <tr>
            <th class="l" scope="col">Country</th>
            <th class="l" scope="col">Region</th>
            <th scope="col">GDP / person</th>
            <th scope="col">Life exp</th>
            <th scope="col">Population</th>
          </tr>
        </thead>
        <tbody id="tbody"></tbody>
      </table>
    </div>
  </section>

  <footer>
    <span class="note">Figures are <b>approximate</b> — decade-scale estimates reshaped from the Maddison Project
    (income) and Gapminder / Human Mortality Database (life expectancy, population). Good enough to show the
    shape of the century, not to cite.</span>
    demo · sloprun.dev
  </footer>
</div>

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    if (!w) return;
    var h = Math.round(Math.max(300, Math.min(540, w * 0.64)));
    var d = Math.min(window.devicePixelRatio || 1, 2.5);
    /* The observer watches #plotwrap and we resize #plotwrap, so it fires again on
       the way out; without this the canvas is cleared and repainted for nothing. */
    if (w === W && h === H && d === dpr) return;
    dpr = d; W = w; H = h;
    narrow = w < 460;
    pad.l = narrow ? 34 : 46;
    pad.b = narrow ? 30 : 34;
    pad.t = narrow ? 26 : 14;
    cv.width  = Math.round(w * dpr);
    cv.height = Math.round(h * dpr);
    cv.style.height = h + "px";
    draw();
  }

  function drawFrame() {
    ctx.fillStyle = rgba(COL.field, 1);
    ctx.fillRect(0, 0, W, H);

    /* the big ghosted year — the Gapminder signature */
    ctx.save();
    ctx.font = "700 " + Math.round(Math.min(150, (W - pad.l - pad.r) * 0.30)) + "px " + MONO;
    ctx.textAlign = "right"; ctx.textBaseline = "bottom";
    ctx.fillStyle = rgba(COL.ink, 0.065);
    ctx.fillText(String(Math.round(year)), W - pad.r - 6, H - pad.b - 6);
    ctx.restore();

    ctx.font = "10px " + MONO;
    ctx.lineWidth = 1;

    /* y grid */
    ctx.textAlign = "right"; ctx.textBaseline = "middle";
    for (var le = 20; le <= 85; le += 10) {
      var y = Math.round(py(le)) + 0.5;
      ctx.strokeStyle = rgba(COL.line, 1);
      ctx.beginPath(); ctx.moveTo(pad.l, y); ctx.lineTo(W - pad.r, y); ctx.stroke();
      ctx.fillStyle = rgba(COL.muted, 1);
      ctx.fillText(String(le), pad.l - 7, y);
    }
    /* x grid */
    ctx.textAlign = "center"; ctx.textBaseline = "top";
    for (var k = 0; k < TICKS_X.length; k++) {
      var gx = Math.round(px(TICKS_X[k])) + 0.5;
      if (gx < pad.l || gx > W - pad.r) continue;
      ctx.strokeStyle = rgba(COL.line, 1);
      ctx.beginPath(); ctx.moveTo(gx, pad.t); ctx.lineTo(gx, H - pad.b); ctx.stroke();
      ctx.fillStyle = rgba(COL.muted, 1);
      ctx.fillText(shortMoney(TICKS_X[k]), gx, H - pad.b + 6);
    }

    /* axis titles */
    ctx.fillStyle = rgba(COL.muted, 1);
    ctx.textAlign = "right"; ctx.textBaseline = "bottom";
    ctx.fillText(narrow ? "income →  log" : "income per person, 2011 $  ·  log scale →", W - pad.r, H - 3);
    if (narrow) {
      ctx.textAlign = "left"; ctx.textBaseline = "top";
      ctx.fillText("↑ life expectancy, years", 4, 5);
    } else {
      ctx.save();
      ctx.translate(11, pad.t + 2);
      ctx.rotate(-Math.PI / 2);
      ctx.textAlign = "right"; ctx.textBaseline = "top";
      ctx.fillText("↑ life expectancy at birth, years", 0, 0);
      ctx.restore();
    }
  }

  function drawTrails() {
    for (var i = 0; i < COUNTRY.length; i++) {
      var c = COUNTRY[i];
      if (!visible(c)) continue;
      var strong = (i === selIdx || i === hoverIdx);
      if (!showTrails && !strong) continue;
      var col = COL[c.region];
      ctx.beginPath();
      var steps = Math.max(1, Math.ceil((year - YEAR0) / 2));
      for (var s = 0; s <= steps; s++) {
        var yy = YEAR0 + (year - YEAR0) * (s / steps);
        var v = sample(c, yy);
        var X = px(v.gdp), Y = py(v.le);
        if (s === 0) ctx.moveTo(X, Y); else ctx.lineTo(X, Y);
      }
      ctx.lineWidth = strong ? 2.5 : 1.5;
      ctx.lineJoin = "round"; ctx.lineCap = "round";
      ctx.strokeStyle = rgba(col, strong ? 0.85 : 0.30);
      ctx.stroke();
    }
  }

  function drawBubbles() {
    hits.length = 0;
    var order = [];
    for (var i = 0; i < COUNTRY.length; i++) if (visible(COUNTRY[i])) order.push(COUNTRY[i]);
    var snap = {};
    for (var j = 0; j < order.length; j++) snap[order[j].i] = sample(order[j], year);
    order.sort(function (a, b) { return snap[b.i].pop - snap[a.i].pop; });

    for (var k = 0; k < order.length; k++) {
      var c = order[k], v = snap[c.i];
      var x = px(v.gdp), y = py(v.le), r = radius(v.pop);
      var col = COL[c.region];
      var active = (c.i === hoverIdx || c.i === selIdx);

      /* 2px surface gap ring so overlapping bubbles stay separable */
      ctx.beginPath(); ctx.arc(x, y, r + 1.2, 0, Math.PI * 2);
      ctx.lineWidth = 2.4; ctx.strokeStyle = rgba(COL.field, 0.95); ctx.stroke();

      ctx.beginPath(); ctx.arc(x, y, r, 0, Math.PI * 2);
      ctx.fillStyle = rgba(col, active ? 0.80 : 0.60); ctx.fill();
      ctx.lineWidth = 2; ctx.strokeStyle = rgba(col, 1); ctx.stroke();

      if (active) {
        ctx.beginPath(); ctx.arc(x, y, r + 5, 0, Math.PI * 2);
        ctx.lineWidth = 1.5; ctx.strokeStyle = rgba(COL.ink, 0.75); ctx.stroke();
      }
      hits.push({ i: c.i, x: x, y: y, r: r });
    }

    /* Direct labels — identity never rests on hue alone. Biggest bubbles win the
       space; anything that would collide with an already-placed label is dropped
       (the table view and the tooltip still name every country). A hovered or
       selected country is always labelled, collision or not. */
    var minR = narrow ? 16 : 11;
    ctx.font = "600 11px " + SANS;
    ctx.textAlign = "center"; ctx.textBaseline = "middle";
    var queue = hits.slice().sort(function (a, b) {
      var aa = (a.i === hoverIdx || a.i === selIdx) ? 1 : 0;
      var bb = (b.i === hoverIdx || b.i === selIdx) ? 1 : 0;
      return aa !== bb ? bb - aa : b.r - a.r;
    });
    var placed = [];
    for (var m = 0; m < queue.length; m++) {
      var h = queue[m];
      var cc = COUNTRY[h.i];
      var on = (h.i === hoverIdx || h.i === selIdx);
      if (h.r < minR && !on) continue;
      var lw = ctx.measureText(cc.name).width;
      /* label sits inside the bubble only when it actually fits */
      var ly = (lw + 8 <= h.r * 2) ? h.y : Math.max(9, h.y - h.r - 8);
      var box = [h.x - lw / 2 - 3, ly - 8, h.x + lw / 2 + 3, ly + 8];
      var clash = false;
      for (var q = 0; q < placed.length && !clash; q++) {
        var o = placed[q];
        clash = box[0] < o[2] && box[2] > o[0] && box[1] < o[3] && box[3] > o[1];
      }
      if (clash && !on) continue;
      placed.push(box);
      ctx.lineWidth = 3.2; ctx.lineJoin = "round";
      ctx.strokeStyle = rgba(COL.field, 0.9);
      ctx.strokeText(cc.name, h.x, ly);
      ctx.fillStyle = rgba(COL.ink, on ? 1 : 0.86);
      ctx.fillText(cc.name, h.x, ly);
    }
  }

  /* Switch every region off and the plot is empty, not broken. Say which. */
  function drawEmpty() {
    var mx = pad.l + (W - pad.l - pad.r) / 2, my = pad.t + (H - pad.t - pad.b) / 2;
    ctx.textAlign = "center"; ctx.textBaseline = "middle";
    ctx.font = "600 13px " + SANS;
    ctx.fillStyle = rgba(COL.ink, 0.75);
    ctx.fillText("Nothing to plot", mx, my - 9);
    ctx.font = "12px " + SANS;
    ctx.fillStyle = rgba(COL.muted, 1);
    ctx.fillText("Turn a region back on in the legend.", mx, my + 10);
  }

  function draw() {
    if (!W || !H) return;
    ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
    ctx.clearRect(0, 0, W, H);
    drawFrame();
    drawTrails();
    drawBubbles();
    if (!hits.length) drawEmpty();
  }

  /* ── readouts ───────────────────────────────────────────────────────────── */
  var stLe = document.getElementById("stLe"), stLeN = document.getElementById("stLeN");
  var stGdp = document.getElementById("stGdp");
  var stGap = document.getElementById("stGap"), stGapN = document.getElementById("stGapN");
  var capSpan = document.getElementById("capSpan"), capText = document.getElementById("capText");
  var tblYear = document.getElementById("tblYear"), tblCount = document.getElementById("tblCount");

  function eventFor(y) {
    for (var i = 0; i < EVENTS.length; i++) if (y >= EVENTS[i][0] && y <= EVENTS[i][1]) return EVENTS[i];
    return EVENTS[EVENTS.length - 1];
  }

  function updateReadouts() {
    var y = Math.round(year);
    var vis = COUNTRY.filter(visible);
    var sumPop = 0, sumLe = 0, gdps = [];
    for (var i = 0; i < vis.length; i++) {
      var v = sample(vis[i], year);
      sumPop += v.pop; sumLe += v.le * v.pop; gdps.push(v.gdp);
    }
    if (vis.length) {
      stLe.textContent = (sumLe / sumPop).toFixed(1) + " yrs";
      stLeN.textContent = "across " + people(sumPop) + " people";
      gdps.sort(function (a, b) { return a - b; });
      var mid = gdps.length % 2 ? gdps[(gdps.length - 1) / 2]
                                : (gdps[gdps.length / 2 - 1] + gdps[gdps.length / 2]) / 2;
      stGdp.textContent = money(mid);
      var ratio = gdps[gdps.length - 1] / gdps[0];
      stGap.textContent = ratio.toFixed(1) + "×";
      stGapN.textContent = money(gdps[gdps.length - 1]) + " vs " + money(gdps[0]);
    } else {
      stLe.textContent = "—"; stLeN.textContent = "no regions shown";
      stGdp.textContent = "—"; stGap.textContent = "—"; stGapN.textContent = "income spread";
    }

    var ev = eventFor(y);
    if (capSpan.textContent !== ev[2]) { capSpan.textContent = ev[2]; capText.textContent = ev[3]; }

    tblYear.textContent = String(y);
    tblCount.textContent = vis.length + (vis.length === 1 ? " country" : " countries");
    if (!tableCard.hidden) renderTable(vis);

    cv.setAttribute("aria-label",
      "Bubble chart, year " + y + ". Horizontal axis: income per person on a log scale. " +
      "Vertical axis: life expectancy. Bubble size is population. " + vis.length +
      " countries shown; population-weighted life expectancy " +
      (vis.length ? (sumLe / sumPop).toFixed(1) + " years." : "none."));
  }

  var tblKey = "";
  function renderTable(vis) {
    var rows = vis.map(function (c) {
      var v = sample(c, year);
      return { c: c, v: v };
    }).sort(function (a, b) { return b.v.gdp - a.v.gdp; });

    /* Same countries in the same order? Repaint the three number cells in place.
       Rebuilding innerHTML 12×/second during playback would blow away a focused
       row button and make a screen reader re-announce it on every frame. */
    var key = rows.map(function (r) { return r.c.i; }).join(",");
    if (key === tblKey && tbody.children.length === rows.length) {
      for (var n = 0; n < rows.length; n++) {
        var tr = tbody.children[n], vv = rows[n].v;
        tr.className = (rows[n].c.i === selIdx) ? "sel" : "";
        tr.children[2].textContent = money(vv.gdp);
        tr.children[3].textContent = vv.le.toFixed(1);
        tr.children[4].textContent = people(vv.pop);
      }
      return;
    }
    tblKey = key;

    var html = "";
    for (var i = 0; i < rows.length; i++) {
      var c = rows[i].c, v = rows[i].v;
      html += '<tr class="' + (c.i === selIdx ? "sel" : "") + '">' +
        '<td class="l"><button type="button" class="rowbtn" data-i="' + c.i + '">' +
          '<span class="sw" style="background:var(' + REGION_VAR[c.region] + ')"></span>' + c.name +
        '</button></td>' +
        '<td class="reg">' + c.region.replace("&", "&amp;") + '</td>' +
        '<td class="num">' + money(v.gdp) + '</td>' +
        '<td class="num">' + v.le.toFixed(1) + '</td>' +
        '<td class="num">' + people(v.pop) + '</td>' +
      '</tr>';
    }
    var act = document.activeElement;
    var keep = (act && act.classList && act.classList.contains("rowbtn"))
             ? act.getAttribute("data-i") : null;
    tbody.innerHTML = html;
    if (keep !== null) {
      var again = tbody.querySelector('.rowbtn[data-i="' + keep + '"]');
      if (again) again.focus();
    }
  }

  /* ── tooltip ────────────────────────────────────────────────────────────── */
  var tipSw = document.getElementById("tipSw"), tipName = document.getElementById("tipName"),
      tipReg = document.getElementById("tipReg"), tipGdp = document.getElementById("tipGdp"),
      tipLe = document.getElementById("tipLe"), tipPop = document.getElementById("tipPop");

  var tipW = 180, tipH = 90, tipFor = -1;
  function showTip(i) {
    var hit = null;
    for (var k = 0; k < hits.length; k++) if (hits[k].i === i) hit = hits[k];
    if (!hit) { tip.classList.remove("on"); return; }
    var c = COUNTRY[i], v = sample(c, year);
    tipSw.style.background = "var(" + REGION_VAR[c.region] + ")";
    tipName.textContent = c.name;
    tipReg.textContent = c.region;
    tipGdp.textContent = money(v.gdp);
    tipLe.textContent = v.le.toFixed(1) + " yrs";
    tipPop.textContent = people(v.pop);
    tip.classList.add("on");
    /* offsetWidth forces a synchronous layout; while playing showTip runs on
       every frame, so only re-measure when the tooltip changes country. */
    if (tipFor !== i) { tipFor = i; tipW = tip.offsetWidth || 180; tipH = tip.offsetHeight || 90; }
    var tw = tipW, th = tipH;
    var left = Math.max(tw / 2 + 4, Math.min(W - tw / 2 - 4, hit.x));
    var top  = hit.y - hit.r - 10;
    if (top - th < 0) top = Math.min(H, hit.y + hit.r + 10 + th);
    tip.style.left = left + "px";
    tip.style.top  = top + "px";
  }
  function hideTip() { tip.classList.remove("on"); }

  function pick(mx, my, slop) {
    var tol = slop || 4;
    var best = -1, bestD = Infinity;
    for (var k = hits.length - 1; k >= 0; k--) {
      var h = hits[k];
      var d = Math.sqrt((mx - h.x) * (mx - h.x) + (my - h.y) * (my - h.y));
      if (d <= h.r + tol && d - h.r < bestD) { bestD = d - h.r; best = h.i; }
    }
    return best;
  }

  /* ── playback ───────────────────────────────────────────────────────────── */
  var raf = 0, lastT = 0;
  var YEARS_PER_SEC = 12;   /* 120 years in 10 s at 1× */

  function setPlaying(on) {
    if (on === playing) return;
    playing = on;
    document.getElementById("playGlyph").textContent = on ? "❚❚" : "▶";
    document.getElementById("playLabel").textContent = on ? "Pause" : "Play";
    playBtn.setAttribute("aria-label", on ? "Pause the animation" : "Play the animation");
    if (on) {
      if (year >= YEND - 0.001) year = YEAR0;
      lastT = 0;
      raf = requestAnimationFrame(tick);
    } else if (raf) {
      cancelAnimationFrame(raf); raf = 0;
    }
  }

  function tick(ts) {
    if (!playing) return;
    if (!lastT) lastT = ts;
    var dt = Math.min(0.1, (ts - lastT) / 1000);
    lastT = ts;
    year += dt * YEARS_PER_SEC * speed;
    if (year >= YEND) {
      year = YEND;
      setYear(year);
      setPlaying(false);
      say("Reached " + YEND + ". Press play to run it again.");
      return;
    }
    setYear(year);
    raf = requestAnimationFrame(tick);
  }

  function setYear(y) {
    year = Math.max(YEAR0, Math.min(YEND, y));
    var r = Math.round(year);
    if (r !== lastShownYear) {
      lastShownYear = r;
      yearOut.textContent = String(r);
      scrub.value = String(r);
      updateReadouts();
    }
    draw();
    if (hoverIdx >= 0) showTip(hoverIdx);
    else if (selIdx >= 0) showTip(selIdx);
  }

  function say(msg) { live.textContent = msg; }

  /* ── wiring ─────────────────────────────────────────────────────────────── */
  playBtn.addEventListener("click", function () { setPlaying(!playing); });

  scrub.addEventListener("input", function () {
    setPlaying(false);
    lastShownYear = -1;
    setYear(parseFloat(scrub.value));
  });

  document.getElementById("rewind").addEventListener("click", function () {
    setPlaying(false);
    lastShownYear = -1;
    setYear(YEAR0);
    say("Rewound to 1900.");
  });

  var spdInputs = document.querySelectorAll('input[name="spd"]');
  for (var s = 0; s < spdInputs.length; s++) {
    spdInputs[s].addEventListener("change", function () {
      speed = parseFloat(this.value);
      say("Speed set to " + this.value + " times normal.");
    });
  }

  var trailsBtn = document.getElementById("trails");
  trailsBtn.addEventListener("click", function () {
    showTrails = !showTrails;
    trailsBtn.setAttribute("aria-pressed", showTrails ? "true" : "false");
    draw();
    say(showTrails ? "Trails on." : "Trails off.");
  });

  var tableCard = document.getElementById("tablecard");
  var tableBtn  = document.getElementById("tableBtn");
  tableBtn.addEventListener("click", function () {
    var on = tableCard.hidden;
    tableCard.hidden = !on;
    tableBtn.setAttribute("aria-pressed", on ? "true" : "false");
    if (on) renderTable(COUNTRY.filter(visible));
    say(on ? "Numbers table shown." : "Numbers table hidden.");
  });

  document.getElementById("legend").addEventListener("click", function (e) {
    var b = e.target.closest ? e.target.closest(".lg") : null;
    if (!b) return;
    var r = b.getAttribute("data-r");
    hidden[r] = !hidden[r];
    b.setAttribute("aria-pressed", hidden[r] ? "false" : "true");
    if (hidden[r]) {
      if (selIdx >= 0 && COUNTRY[selIdx].region === r) selIdx = -1;
      if (hoverIdx >= 0 && COUNTRY[hoverIdx].region === r) { hoverIdx = -1; hideTip(); }
    }
    lastShownYear = -1;
    setYear(year);
    say(r + (hidden[r] ? " hidden." : " shown."));
  });

  tbody.addEventListener("click", function (e) {
    var b = e.target.closest ? e.target.closest(".rowbtn") : null;
    if (!b) return;
    selectCountry(parseInt(b.getAttribute("data-i"), 10));
  });

  function selectCountry(i) {
    selIdx = (selIdx === i) ? -1 : i;
    draw();
    if (selIdx >= 0) {
      showTip(selIdx);
      var c = COUNTRY[selIdx], v = sample(c, year);
      say(c.name + " selected. " + Math.round(year) + ": income " + money(v.gdp) +
          ", life expectancy " + v.le.toFixed(1) + " years, population " + people(v.pop) + ".");
    } else { hideTip(); say("Selection cleared."); }
    if (!tableCard.hidden) renderTable(COUNTRY.filter(visible));
  }

  /* pointer */
  cv.addEventListener("pointermove", function (e) {
    var rect = cv.getBoundingClientRect();
    var i = pick(e.clientX - rect.left, e.clientY - rect.top);
    if (i !== hoverIdx) {
      hoverIdx = i;
      draw();
      if (i >= 0) showTip(i); else if (selIdx >= 0) showTip(selIdx); else hideTip();
      cv.style.cursor = i >= 0 ? "pointer" : "default";
    } else if (i >= 0) { showTip(i); }
  });
  cv.addEventListener("pointerleave", function () {
    hoverIdx = -1; draw();
    if (selIdx >= 0) showTip(selIdx); else hideTip();
  });
  cv.addEventListener("pointerdown", function (e) {
    var rect = cv.getBoundingClientRect();
    var i = pick(e.clientX - rect.left, e.clientY - rect.top,
                 e.pointerType === "touch" ? 14 : 4);
    /* Touch has no hover. Leaving hoverIdx set meant a second tap de-selected the
       country but setYear kept re-opening its tooltip on the next frame. */
    if (e.pointerType === "touch") hoverIdx = -1;
    if (i >= 0) { selectCountry(i); }
    else if (selIdx >= 0) { selIdx = -1; draw(); hideTip(); }
  });

  /* keyboard on the plot */
  cv.addEventListener("keydown", function (e) {
    var k = e.key, step = e.shiftKey ? 10 : 1;
    if (k === "ArrowRight" || k === "ArrowLeft") {
      e.preventDefault(); setPlaying(false);
      lastShownYear = -1;
      setYear(Math.round(year) + (k === "ArrowRight" ? step : -step));
      say(String(Math.round(year)));
    } else if (k === "ArrowUp" || k === "ArrowDown") {
      e.preventDefault();
      var vis = COUNTRY.filter(visible);
      if (!vis.length) return;
      var at = -1;
      for (var n = 0; n < vis.length; n++) if (vis[n].i === selIdx) at = n;
      if (at === -1) at = (k === "ArrowDown") ? 0 : vis.length - 1;
      else at = (at + (k === "ArrowDown" ? 1 : -1) + vis.length) % vis.length;
      selIdx = -1; selectCountry(vis[at].i);
    } else if (k === " " || k === "Enter") {
      e.preventDefault(); setPlaying(!playing);
      say(playing ? "Playing." : "Paused at " + Math.round(year) + ".");
    }
  });

  cv.setAttribute("aria-describedby", "canvasHelp");

  /* ── boot ───────────────────────────────────────────────────────────────── */
  readTheme();
  if (window.ResizeObserver) {
    new ResizeObserver(resize).observe(wrapEl);
  } else {
    window.addEventListener("resize", resize);
  }
  resize();
  lastShownYear = -1;
  setYear(YEAR0);

  if (reduced) {
    setPlaying(false);
    say("Reduced motion is on, so the animation starts paused. Press play, or drag the year slider.");
  } else {
    setPlaying(true);
  }

  document.addEventListener("visibilitychange", function () {
    if (document.hidden && playing) setPlaying(false);
  });
})();
</script>
</body>
</html>