diff --git a/web-ui/arduino-emulator.html b/web-ui/arduino-emulator.html
index e46344f..f1f1585 100644
--- a/web-ui/arduino-emulator.html
+++ b/web-ui/arduino-emulator.html
@@ -138,7 +138,7 @@
   }
   #canvas-zoom-overlay.open { display:flex; }
   #canvas-zoom-img {
-    image-rendering:pixelated; max-width:90vw; max-height:90vh;
+    image-rendering:pixelated;
     border:2px solid #333; border-radius:4px;
     box-shadow:0 8px 40px rgba(0,0,0,.8);
   }
@@ -7927,31 +7927,54 @@ function mobToggleBoard(){
 (function() {
   const overlay = document.createElement('div');
   overlay.id = 'canvas-zoom-overlay';
-  overlay.innerHTML = '<img id="canvas-zoom-img"><div id="canvas-zoom-hint">클릭 또는 ESC로 닫기</div>';
+  const zoomCanvas = document.createElement('canvas');
+  zoomCanvas.id = 'canvas-zoom-img';
+  overlay.appendChild(zoomCanvas);
+  const hint = document.createElement('div');
+  hint.id = 'canvas-zoom-hint';
+  hint.textContent = '클릭 또는 ESC로 닫기';
+  overlay.appendChild(hint);
   document.body.appendChild(overlay);
 
-  function openZoom(canvas) {
-    const img = document.getElementById('canvas-zoom-img');
-    img.src = canvas.toDataURL();
-    // 자연 크기의 3배, 화면 90% 이내
-    const scale = Math.min(3, window.innerWidth * 0.9 / canvas.width, window.innerHeight * 0.9 / canvas.height);
-    img.style.width  = (canvas.width  * scale) + 'px';
-    img.style.height = (canvas.height * scale) + 'px';
-    overlay.classList.add('open');
+  let _src = null, _rafId = null;
+
+  function _loop() {
+    if (!_src || !overlay.classList.contains('open')) return;
+    const ctx = zoomCanvas.getContext('2d');
+    ctx.imageSmoothingEnabled = false;
+    ctx.drawImage(_src, 0, 0, zoomCanvas.width, zoomCanvas.height);
+    _rafId = requestAnimationFrame(_loop);
   }
 
-  function closeZoom() { overlay.classList.remove('open'); }
+  function openZoom(canvas) {
+    _src = canvas;
+    // 화면의 90% 이내에서 최대 정수 배율
+    const maxScale = Math.min(
+      Math.floor(window.innerWidth  * 0.9 / canvas.width),
+      Math.floor(window.innerHeight * 0.9 / canvas.height)
+    );
+    const scale = Math.max(1, maxScale);
+    zoomCanvas.width  = canvas.width  * scale;
+    zoomCanvas.height = canvas.height * scale;
+    overlay.classList.add('open');
+    cancelAnimationFrame(_rafId);
+    _loop();
+  }
+
+  function closeZoom() {
+    overlay.classList.remove('open');
+    cancelAnimationFrame(_rafId);
+    _src = null;
+  }
 
   overlay.addEventListener('click', closeZoom);
   document.addEventListener('keydown', e => { if (e.key === 'Escape') closeZoom(); });
 
-  // body 끝에서 실행되므로 DOM 이미 준비됨 — 직접 연결
   ['tft-canvas', 'oled-canvas'].forEach(id => {
     const c = document.getElementById(id);
-    if (c) c.addEventListener('click', () => openZoom(c));
+    if (c) c.addEventListener('click', e => { e.stopPropagation(); openZoom(c); });
   });
 
-  // canvas가 나중에 그려질 수 있으므로 전역 노출
   window._canvasZoomOpen = openZoom;
 })();
 </script>