Wait for full animation preview duration

src/web/public/js/slides/slide-animation-editor.js

@@ -132,6 +132,17 @@ export function createSlideAnimationEditor(options) {
   function getPreviewElements() {
     return Array.prototype.slice.call(previewHost.querySelectorAll('.slide-preview-region[data-region-key]'));
   }
+  function getAnimationDurationMs(element, fallbackDurationMs) {
+    if (typeof window.getComputedStyle !== 'function') return fallbackDurationMs;
+    var durations = String(window.getComputedStyle(element).animationDuration || '').split(',');
+    var longestDuration = durations.reduce(function (longest, value) {
+      var match = value.trim().match(/^([\d.]+)\s*(ms|s)$/i);
+      if (!match) return longest;
+      var duration = Number(match[1]) * (match[2].toLowerCase() === 's' ? 1000 : 1);
+      return Number.isFinite(duration) ? Math.max(longest, duration) : longest;
+    }, 0);
+    return longestDuration || fallbackDurationMs;
+  }
   function stopPreview() {
     if (previewTimer) window.clearTimeout(previewTimer);
     previewTimer = 0;
@@ -185,7 +196,7 @@ export function createSlideAnimationEditor(options) {
       void element.offsetWidth;
       element.classList.add('animate__animated', 'animate__' + preset);
       if (mode === 'loop') element.classList.add('animate__repeat-1');
-      longest = Math.max(longest, delay + duration * iterations);
+      longest = Math.max(longest, delay + getAnimationDurationMs(element, duration) * iterations);
     });
     updatePreviewButtons();
     previewTimer = window.setTimeout(function () {