diff --git a/web/public/app.js b/web/public/app.js
index 3aff8ab..c1fc1a3 100644
--- a/web/public/app.js
+++ b/web/public/app.js
@@ -731,10 +731,24 @@ function attachLiveJob(id, target, name, pinnedAgents) {
 }
 
 function updatePinnedLine() {
-  const n = state.currentJob?.pinnedAgents?.length || 0;
-  $('#livePinned').textContent = n
-    ? `${n} pinned lead(s): ${state.currentJob.pinnedAgents.join(', ')}`
-    : 'auto — recon-driven agent selection (no leads pinned)';
+  const el = $('#livePinned');
+  const pins = state.currentJob?.pinnedAgents || [];
+  const n = pins.length;
+  if (!n) { el.textContent = 'auto — recon-driven agent selection (no leads pinned)'; el.title = ''; el.onclick = null; el.classList.remove('expandable'); return; }
+  // A /run with every lead pinned (hundreds of agents) must not flood the
+  // header and push the tabs off-screen — collapse to a count + preview the
+  // operator can click to expand.
+  const CAP = 6;
+  const render = (expanded) => {
+    const shown = expanded ? pins : pins.slice(0, CAP);
+    const more = (!expanded && n > CAP) ? ` … +${n - CAP} more` : '';
+    el.textContent = `${n} pinned lead(s): ${shown.join(', ')}${more}`;
+    el.classList.toggle('expandable', n > CAP);
+  };
+  let expanded = false;
+  render(false);
+  el.title = n > CAP ? 'Click to show all pinned leads' : pins.join(', ');
+  el.onclick = n > CAP ? () => { expanded = !expanded; render(expanded); el.title = expanded ? 'Click to collapse' : 'Click to show all pinned leads'; } : null;
 }
 
 // Resume a live view across a page reload: the server-side job outlives the
diff --git a/web/public/style.css b/web/public/style.css
index fcf90dc..0ec13f8 100644
--- a/web/public/style.css
+++ b/web/public/style.css
@@ -481,6 +481,13 @@ textarea { resize: vertical; min-height: 72px; }
 .run-head-main { min-width: 0; }
 .run-target { font-size: var(--fs-lg); font-weight: 600; font-family: var(--mono); overflow-wrap: anywhere; }
 .run-meta { display: flex; align-items: center; gap: var(--sp-3); margin-top: var(--sp-1); font-size: var(--fs-sm); color: var(--text-dim); font-family: var(--mono); }
+/* Pinned-leads line: never let a /run with hundreds of pinned agents flood the
+   header and push the tabs below the fold. Collapsed by default (JS truncates
+   to a preview + count); clicking expands it, capped so it still scrolls. */
+#livePinned { display: block; line-height: 1.5; }
+#livePinned.expandable { cursor: pointer; }
+#livePinned.expandable:hover { color: var(--text); }
+#livePinned { max-height: 4.5em; overflow-y: auto; }
 #liveTargetSub:empty, #detailTargetSub:empty { display: none; }
 .run-facts { flex-wrap: wrap; font-size: var(--fs-xs); color: var(--text-faint); }
 .run-facts span:not(:last-child)::after { content: " ·"; }