diff --git a/index.html b/index.html
index fc86178..81418a4 100644
--- a/index.html
+++ b/index.html
@@ -490,6 +490,28 @@
   })).filter(v => v.vals.some(val => val != null));
 };
 
+// React owns the content; Tippy owns placement relative to the actual SVG dot.
+function TimelinePointTooltip({ anchor, children }) {
+  const [content] = useState(() => document.createElement("div"));
+  const tooltip = React.useRef(null);
+  React.useEffect(() => {
+    if (!anchor || !window.tippy) return;
+    const instance = window.tippy(anchor, {
+      content, trigger: "manual", theme: "light-border", arrow: true,
+      maxWidth: 340, offset: [0, 8], placement: "top", appendTo: () => document.body,
+      animation: false,
+    });
+    tooltip.current = instance;
+    instance.show();
+    return () => { instance.destroy(); tooltip.current = null; };
+  }, [anchor, content]);
+  // Scale changes can move a pinned dot without changing its DOM element.
+  React.useLayoutEffect(() => {
+    if (tooltip.current && tooltip.current.popperInstance) tooltip.current.popperInstance.update();
+  });
+  return ReactDOM.createPortal(children, content);
+}
+
 /* ---------------- time-series chart ---------------- */
 // Before Oct 21 only the median is visible until hovered or selected; then
 // model answers appear as ink-gray circles. Since Oct 21 each prompt condition
@@ -542,17 +564,17 @@
   const h = horizon;
   const med = q.median[h] || [];
   const fmtV = tlFmtFor(q);
-  const [active, setActive] = useState(null);         // { i, id }, null id = median
+  const [active, setActive] = useState(null);         // { i, id, anchor }, null id = median
   const [pinned, setPinned] = useState(false);        // click/tap keeps the details open
   const hv = active ? active.i : null;
   const hvar = active && active.id != null ? active : null;
   const clear = () => { setActive(null); setPinned(false); };
-  const hover = (i, id = null) => { if (!pinned) setActive({ i, id }); };
+  const hover = (e, i, id = null) => { if (!pinned) setActive({ i, id, anchor: e.currentTarget.lastElementChild }); };
   const leave = () => { if (!pinned) setActive(null); };
   const select = (e, i, id = null) => {
     e.stopPropagation();
     if (pinned && hv === i && (active && active.id) === id) clear();
-    else { setActive({ i, id }); setPinned(true); }
+    else { setActive({ i, id, anchor: e.currentTarget.lastElementChild }); setPinned(true); }
   };
   const keySelect = (e, i, id = null) => {
     if (e.key === "Enter" || e.key === " ") { e.preventDefault(); select(e, i, id); }
@@ -613,12 +635,6 @@
   const li = med.map((v, i) => (v != null ? i : -1)).reduce((a, b) => Math.max(a, b), -1);
   // Right-margin label: the latest median, kept above the date labels.
   const endLabel = li >= 0 ? { v: med[li], y: Math.min(y(med[li]), H - pad.b - 2), xi: li } : null;
-  // A hover card beside date i, flipped left in the right 40%.
-  const tipStyle = i => ({ ...(narrow ? { position: "relative", marginTop: 8 } : {
-    position: "absolute", top: 8, left: `${(x(i) / W) * 100}%`,
-    transform: x(i) > W * 0.6 ? "translateX(calc(-100% - 8px))" : "translateX(10px)" }),
-    background: "var(--panel)", border: "1px solid var(--line)", borderRadius: 8, padding: "9px 11px",
-    boxShadow: "var(--shadow)", pointerEvents: "none", maxWidth: narrow ? "100%" : 340 });
 
   return (
     <div ref={box} style={{ position: "relative", minWidth: 0 }} onKeyDown={e => { if (e.key === "Escape") clear(); }}>
@@ -680,7 +696,7 @@
           <g key={"m" + i} role="button" tabIndex={0} style={{ cursor: "pointer" }}
             aria-label={`${snapshots[i].date}, ensemble median ${fmtV(v)}; show model forecasts`}
             aria-pressed={pinned && hv === i && !hvar}
-            onMouseEnter={() => hover(i)} onMouseLeave={leave} onFocus={() => hover(i)} onBlur={leave}
+            onMouseEnter={e => hover(e, i)} onMouseLeave={leave} onFocus={e => hover(e, i)} onBlur={leave}
             onClick={e => select(e, i)} onKeyDown={e => keySelect(e, i)}>
             <circle cx={x(i)} cy={y(v)} r="10" fill="transparent" />
             <circle cx={x(i)} cy={y(v)} r="5" fill="var(--panel)" stroke="var(--ink)" strokeWidth="2.6" />
@@ -693,7 +709,7 @@
             role="button" tabIndex={0} style={{ cursor: "pointer" }}
             aria-label={`${snapshots[i].date}, ${v.label} prompt ${fmtV(v.vals[i])}; show model forecasts`}
             aria-pressed={pinned && hv === i && hvar && hvar.id === v.id ? true : false}
-            onMouseEnter={() => hover(i, v.id)} onMouseLeave={leave} onFocus={() => hover(i, v.id)} onBlur={leave}
+            onMouseEnter={e => hover(e, i, v.id)} onMouseLeave={leave} onFocus={e => hover(e, i, v.id)} onBlur={leave}
             onClick={e => select(e, i, v.id)} onKeyDown={e => keySelect(e, i, v.id)}>
             <circle cx={cx} cy={cy} r="10" fill="transparent" />
             <circle cx={cx} cy={cy} r="4.5" fill={v.color} stroke="var(--panel)" strokeWidth="1.5" />
@@ -702,7 +718,7 @@
       </svg>
 
       {hovered && (
-        <div style={tipStyle(hvar.i)}>
+        <TimelinePointTooltip anchor={active.anchor}>
           {hoveredModels.map(([label, val]) => (
             <div key={label} style={{ display: "flex", justifyContent: "space-between", gap: 14, fontSize: 12 }}>
               <span style={{ display: "flex", alignItems: "center", gap: 6 }}>
@@ -711,10 +727,10 @@
               <span className="mono">{fmtV(val)}</span>
             </div>
           ))}
-        </div>
+        </TimelinePointTooltip>
       )}
       {hv != null && !hovered && (
-        <div style={tipStyle(hv)}>
+        <TimelinePointTooltip anchor={active.anchor}>
           <div style={{ fontSize: 11, color: "var(--ink-faint)", marginBottom: 6 }}>
             {snapshots[hv].date} · <span style={{ color: "var(--ink)", fontWeight: 600 }}>by {h}</span>
             {hasVar(hv) ? ` · ${variants.filter(v => v.vals[hv] != null).length} prompts per model · each model = mean of its prompts`
@@ -744,7 +760,7 @@
               </span>
             </div>
           ))}
-        </div>
+        </TimelinePointTooltip>
       )}
     </div>
   );
diff --git a/web/demo/19-live-timeline.jsx b/web/demo/19-live-timeline.jsx
index cbbc01f..5fb2527 100644
--- a/web/demo/19-live-timeline.jsx
+++ b/web/demo/19-live-timeline.jsx
@@ -49,6 +49,28 @@ const tlVariants = (q, horizon, snapshots) => {
   })).filter(v => v.vals.some(val => val != null));
 };
 
+// React owns the content; Tippy owns placement relative to the actual SVG dot.
+function TimelinePointTooltip({ anchor, children }) {
+  const [content] = useState(() => document.createElement("div"));
+  const tooltip = React.useRef(null);
+  React.useEffect(() => {
+    if (!anchor || !window.tippy) return;
+    const instance = window.tippy(anchor, {
+      content, trigger: "manual", theme: "light-border", arrow: true,
+      maxWidth: 340, offset: [0, 8], placement: "top", appendTo: () => document.body,
+      animation: false,
+    });
+    tooltip.current = instance;
+    instance.show();
+    return () => { instance.destroy(); tooltip.current = null; };
+  }, [anchor, content]);
+  // Scale changes can move a pinned dot without changing its DOM element.
+  React.useLayoutEffect(() => {
+    if (tooltip.current && tooltip.current.popperInstance) tooltip.current.popperInstance.update();
+  });
+  return ReactDOM.createPortal(children, content);
+}
+
 /* ---------------- time-series chart ---------------- */
 // Before Oct 21 only the median is visible until hovered or selected; then
 // model answers appear as ink-gray circles. Since Oct 21 each prompt condition
@@ -101,17 +123,17 @@ function TimelineChart({ q, snapshots, horizon, scale }) {
   const h = horizon;
   const med = q.median[h] || [];
   const fmtV = tlFmtFor(q);
-  const [active, setActive] = useState(null);         // { i, id }, null id = median
+  const [active, setActive] = useState(null);         // { i, id, anchor }, null id = median
   const [pinned, setPinned] = useState(false);        // click/tap keeps the details open
   const hv = active ? active.i : null;
   const hvar = active && active.id != null ? active : null;
   const clear = () => { setActive(null); setPinned(false); };
-  const hover = (i, id = null) => { if (!pinned) setActive({ i, id }); };
+  const hover = (e, i, id = null) => { if (!pinned) setActive({ i, id, anchor: e.currentTarget.lastElementChild }); };
   const leave = () => { if (!pinned) setActive(null); };
   const select = (e, i, id = null) => {
     e.stopPropagation();
     if (pinned && hv === i && (active && active.id) === id) clear();
-    else { setActive({ i, id }); setPinned(true); }
+    else { setActive({ i, id, anchor: e.currentTarget.lastElementChild }); setPinned(true); }
   };
   const keySelect = (e, i, id = null) => {
     if (e.key === "Enter" || e.key === " ") { e.preventDefault(); select(e, i, id); }
@@ -172,12 +194,6 @@ function TimelineChart({ q, snapshots, horizon, scale }) {
   const li = med.map((v, i) => (v != null ? i : -1)).reduce((a, b) => Math.max(a, b), -1);
   // Right-margin label: the latest median, kept above the date labels.
   const endLabel = li >= 0 ? { v: med[li], y: Math.min(y(med[li]), H - pad.b - 2), xi: li } : null;
-  // A hover card beside date i, flipped left in the right 40%.
-  const tipStyle = i => ({ ...(narrow ? { position: "relative", marginTop: 8 } : {
-    position: "absolute", top: 8, left: `${(x(i) / W) * 100}%`,
-    transform: x(i) > W * 0.6 ? "translateX(calc(-100% - 8px))" : "translateX(10px)" }),
-    background: "var(--panel)", border: "1px solid var(--line)", borderRadius: 8, padding: "9px 11px",
-    boxShadow: "var(--shadow)", pointerEvents: "none", maxWidth: narrow ? "100%" : 340 });
 
   return (
     <div ref={box} style={{ position: "relative", minWidth: 0 }} onKeyDown={e => { if (e.key === "Escape") clear(); }}>
@@ -239,7 +255,7 @@ function TimelineChart({ q, snapshots, horizon, scale }) {
           <g key={"m" + i} role="button" tabIndex={0} style={{ cursor: "pointer" }}
             aria-label={`${snapshots[i].date}, ensemble median ${fmtV(v)}; show model forecasts`}
             aria-pressed={pinned && hv === i && !hvar}
-            onMouseEnter={() => hover(i)} onMouseLeave={leave} onFocus={() => hover(i)} onBlur={leave}
+            onMouseEnter={e => hover(e, i)} onMouseLeave={leave} onFocus={e => hover(e, i)} onBlur={leave}
             onClick={e => select(e, i)} onKeyDown={e => keySelect(e, i)}>
             <circle cx={x(i)} cy={y(v)} r="10" fill="transparent" />
             <circle cx={x(i)} cy={y(v)} r="5" fill="var(--panel)" stroke="var(--ink)" strokeWidth="2.6" />
@@ -252,7 +268,7 @@ function TimelineChart({ q, snapshots, horizon, scale }) {
             role="button" tabIndex={0} style={{ cursor: "pointer" }}
             aria-label={`${snapshots[i].date}, ${v.label} prompt ${fmtV(v.vals[i])}; show model forecasts`}
             aria-pressed={pinned && hv === i && hvar && hvar.id === v.id ? true : false}
-            onMouseEnter={() => hover(i, v.id)} onMouseLeave={leave} onFocus={() => hover(i, v.id)} onBlur={leave}
+            onMouseEnter={e => hover(e, i, v.id)} onMouseLeave={leave} onFocus={e => hover(e, i, v.id)} onBlur={leave}
             onClick={e => select(e, i, v.id)} onKeyDown={e => keySelect(e, i, v.id)}>
             <circle cx={cx} cy={cy} r="10" fill="transparent" />
             <circle cx={cx} cy={cy} r="4.5" fill={v.color} stroke="var(--panel)" strokeWidth="1.5" />
@@ -261,7 +277,7 @@ function TimelineChart({ q, snapshots, horizon, scale }) {
       </svg>
 
       {hovered && (
-        <div style={tipStyle(hvar.i)}>
+        <TimelinePointTooltip anchor={active.anchor}>
           {hoveredModels.map(([label, val]) => (
             <div key={label} style={{ display: "flex", justifyContent: "space-between", gap: 14, fontSize: 12 }}>
               <span style={{ display: "flex", alignItems: "center", gap: 6 }}>
@@ -270,10 +286,10 @@ function TimelineChart({ q, snapshots, horizon, scale }) {
               <span className="mono">{fmtV(val)}</span>
             </div>
           ))}
-        </div>
+        </TimelinePointTooltip>
       )}
       {hv != null && !hovered && (
-        <div style={tipStyle(hv)}>
+        <TimelinePointTooltip anchor={active.anchor}>
           <div style={{ fontSize: 11, color: "var(--ink-faint)", marginBottom: 6 }}>
             {snapshots[hv].date} · <span style={{ color: "var(--ink)", fontWeight: 600 }}>by {h}</span>
             {hasVar(hv) ? ` · ${variants.filter(v => v.vals[hv] != null).length} prompts per model · each model = mean of its prompts`
@@ -303,7 +319,7 @@ function TimelineChart({ q, snapshots, horizon, scale }) {
               </span>
             </div>
           ))}
-        </div>
+        </TimelinePointTooltip>
       )}
     </div>
   );