fix: editor PreviewPanel updates

editor/components/PreviewPanel.vue

@@ -52,6 +52,8 @@ function togglePlay() {
   border-left: 1px solid rgba(255,255,255,0.08);
   display: flex;
   flex-direction: column;
+  align-items: center;
+  justify-content: center;
 }
 
 .preview-header {
@@ -61,17 +63,24 @@ function togglePlay() {
   border-bottom: 1px solid rgba(255,255,255,0.06);
   text-transform: uppercase;
   letter-spacing: 1px;
+  width: 100%;
+  flex-shrink: 0;
 }
 
 .preview-video {
-  padding: 12px;
   display: flex;
   flex-direction: column;
   gap: 8px;
+  width: 100%;
+  max-width: 100%;
+  aspect-ratio: 16 / 9;
+  max-height: 100%;
 }
 
 .preview-video video {
   width: 100%;
+  height: 100%;
+  object-fit: contain;
   background: #000;
   border-radius: 4px;
 }