diff --git a/index.html b/index.html
index 62bff7c..f905ec0 100644
--- a/index.html
+++ b/index.html
@@ -39,10 +39,13 @@
       <p class="text-sm text-gray-500 dark:text-gray-400 mt-1">Capture a photo from your webcam and save it using the student number.</p>
     </header>
 
-    <div class="relative bg-black rounded-xl overflow-hidden aspect-video flex items-center justify-center">
-      <video id="video" class="w-full h-full object-cover" autoplay playsinline muted></video>
-      <img id="preview-img" class="hidden w-full h-full object-cover" alt="Captured student photo">
-      <p id="camera-status" class="absolute text-gray-300 text-sm">Requesting camera access…</p>
+    <div class="space-y-2">
+      <div class="relative bg-black rounded-xl overflow-hidden aspect-[145/185] max-w-[280px] mx-auto flex items-center justify-center">
+        <video id="video" class="w-full h-full object-cover" autoplay playsinline muted></video>
+        <img id="preview-img" class="hidden w-full h-full object-cover" alt="Captured student photo">
+        <p id="camera-status" class="absolute text-gray-300 text-sm px-4 text-center">Requesting camera access…</p>
+      </div>
+      <p class="text-xs text-gray-400 dark:text-gray-500 text-center">Frame matches the final 145×185 photo — fill it with the student's face and shoulders.</p>
     </div>
 
     <canvas id="canvas" class="hidden"></canvas>
diff --git a/js/app.js b/js/app.js
index 9ad02e5..79fd1c5 100644
--- a/js/app.js
+++ b/js/app.js
@@ -7,6 +7,10 @@ const inputError = document.getElementById('input-error');
 const captureBtn = document.getElementById('capture-btn');
 const downloadLink = document.getElementById('download-link');
 
+const OUTPUT_WIDTH = 145;
+const OUTPUT_HEIGHT = 185;
+const TARGET_RATIO = OUTPUT_WIDTH / OUTPUT_HEIGHT;
+
 let captured = false;
 
 async function startCamera() {
@@ -53,10 +57,27 @@ function capturePhoto() {
   }
   inputError.classList.add('hidden');
 
-  canvas.width = video.videoWidth;
-  canvas.height = video.videoHeight;
+  const videoWidth = video.videoWidth;
+  const videoHeight = video.videoHeight;
+  const videoRatio = videoWidth / videoHeight;
+
+  let sx, sy, sw, sh;
+  if (videoRatio > TARGET_RATIO) {
+    sh = videoHeight;
+    sw = sh * TARGET_RATIO;
+    sx = (videoWidth - sw) / 2;
+    sy = 0;
+  } else {
+    sw = videoWidth;
+    sh = sw / TARGET_RATIO;
+    sx = 0;
+    sy = (videoHeight - sh) / 2;
+  }
+
+  canvas.width = OUTPUT_WIDTH;
+  canvas.height = OUTPUT_HEIGHT;
   const ctx = canvas.getContext('2d');
-  ctx.drawImage(video, 0, 0, canvas.width, canvas.height);
+  ctx.drawImage(video, sx, sy, sw, sh, 0, 0, OUTPUT_WIDTH, OUTPUT_HEIGHT);
 
   const dataUrl = canvas.toDataURL('image/png');
   const filename = `${sanitizeFilename(studentNumber)}.png`;