diff --git a/plantuml-3d-renderer.html b/plantuml-3d-renderer.html
index 878bd3d..9cae5ce 100644
--- a/plantuml-3d-renderer.html
+++ b/plantuml-3d-renderer.html
@@ -285,6 +285,14 @@ C --> ConC
     </div>
     <div id="err"></div>
 
+    <div class="panel-label" style="margin-top:16px">Bug counts (JSON — alias: count)</div>
+    <textarea id="bugJson" spellcheck="false" rows="3"
+      placeholder='{"ConA":3,"AdpA":1,"L":7}'></textarea>
+    <div class="btn-row">
+      <button class="primary" onclick="applyBugs()">Apply bugs</button>
+      <button onclick="clearBugs()">Clear</button>
+    </div>
+
     <div class="legend">
       <div class="legend-item">
         <div class="legend-swatch" style="background:var(--top-gray)"></div> ECU / top-level
@@ -396,7 +404,7 @@ function makePoly(pts, cssVar) {
   return el;
 }
 
-function makeBlock(svg, x, y, W, H, pal, label, sublabel, clickable) {
+function makeBlock(svg, x, y, W, H, pal, label, sublabel, clickable, bugCount = 0) {
   const g = ns('g');
   if (clickable) g.classList.add('zoomable');
 
@@ -424,6 +432,25 @@ function makeBlock(svg, x, y, W, H, pal, label, sublabel, clickable) {
     g.appendChild(ts);
   }
 
+  if (bugCount > 0) {
+    const bx = x + hw - 8, by = y + 8;
+    const circle = ns('circle');
+    circle.setAttribute('cx', bx); circle.setAttribute('cy', by);
+    circle.setAttribute('r', '9');
+    circle.setAttribute('fill', '#d32f2f');
+    circle.setAttribute('stroke', '#fff'); circle.setAttribute('stroke-width', '1.5');
+    g.appendChild(circle);
+    const bt = ns('text');
+    bt.setAttribute('x', bx); bt.setAttribute('y', by);
+    bt.setAttribute('text-anchor', 'middle');
+    bt.setAttribute('dominant-baseline', 'central');
+    bt.setAttribute('fill', '#fff');
+    bt.setAttribute('font-size', '8');
+    bt.setAttribute('font-weight', 'bold');
+    bt.textContent = bugCount > 99 ? '99+' : String(bugCount);
+    g.appendChild(bt);
+  }
+
   svg.appendChild(g);
   return {
     g,
@@ -463,7 +490,7 @@ function makeLine(svg, x1, y1, x2, y2) {
   svg.appendChild(p);
 }
 
-let state = { parsed: null, viewStack: [] };
+let state = { parsed: null, viewStack: [], bugData: {}, currentNode: null };
 
 function render() {
   const src = document.getElementById('puml').value;
@@ -476,7 +503,30 @@ function render() {
   drawLevel(parsed.root);
 }
 
+function setBugData(data) {
+  state.bugData = data || {};
+  if (state.currentNode) drawLevel(state.currentNode);
+}
+window.setBugData = setBugData;
+
+function applyBugs() {
+  const raw = document.getElementById('bugJson').value.trim();
+  document.getElementById('err').textContent = '';
+  if (!raw) { setBugData({}); return; }
+  try {
+    setBugData(JSON.parse(raw));
+  } catch (e) {
+    document.getElementById('err').textContent = 'Bug JSON error: ' + e.message;
+  }
+}
+
+function clearBugs() {
+  document.getElementById('bugJson').value = '';
+  setBugData({});
+}
+
 function drawLevel(node) {
+  state.currentNode = node;
   const svg = document.getElementById('iso');
   svg.innerHTML = '';
   makeArrow(svg);
@@ -510,7 +560,8 @@ function drawLevel(node) {
     const pal      = guessColor(child);
     const canZoom  = child.children.length > 0;
     const sub      = canZoom ? 'click to expand →' : null;
-    const blk = makeBlock(svg, x, y, W, H, pal, child.label, sub, canZoom);
+    const bugs     = state.bugData[child.id] || 0;
+    const blk = makeBlock(svg, x, y, W, H, pal, child.label, sub, canZoom, bugs);
     positions[child.id] = blk;
 
     if (canZoom) {