internal/web/static/new.js

@@ -199,8 +199,11 @@ function finishCreate(data) {
     try {
       navigator.clipboard.writeText(url);
       copyBtn.classList.add('ok');               // in-place success feedback (#53)
+      // #260: pin the pre-swap width so the wider/narrower glyph never
+      // shifts neighbouring elements; release it when the label restores.
+      copyBtn.style.minWidth = Math.ceil(copyBtn.getBoundingClientRect().width) + 'px';
       copyBtn.textContent = '✓';
-      setTimeout(() => { copyBtn.classList.remove('ok'); copyBtn.textContent = '⧉'; }, 2000);
+      setTimeout(() => { copyBtn.classList.remove('ok'); copyBtn.textContent = '⧉'; copyBtn.style.minWidth = ''; }, 2000);
     } catch(e) { toast('Copy failed', 'error'); }
   });
   // token carried via sessionStorage, never in the URL (#143)

internal/web/static/paste.js

@@ -19,6 +19,12 @@ function toggleStats() {
 function copyFeedback(btn) {
   if (!btn) return;
   if (!btn.dataset.label) btn.dataset.label = btn.textContent; // remember the original label (Copy/Link)
+  // #260: keep the button width static during the feedback so surrounding
+  // elements never jump. Pin the pre-swap width, release it on restore.
+  if (!btn.dataset.pinned) {
+    btn.style.minWidth = Math.ceil(btn.getBoundingClientRect().width) + 'px';
+    btn.dataset.pinned = '1';
+  }
   btn.classList.add('ok');
   btn.textContent = '✓';
   clearTimeout(btn._okh);