diff --git a/atlas/templates/atlas/collection_mark_question.html b/atlas/templates/atlas/collection_mark_question.html
index 46b0a320..31cd07a8 100644
--- a/atlas/templates/atlas/collection_mark_question.html
+++ b/atlas/templates/atlas/collection_mark_question.html
@@ -33,7 +33,7 @@
     </form>
 
 
-    <div class="offcanvas offcanvas-end bg-black opacity-50" data-bs-scroll="true" data-bs-backdrop="false" tabindex="-1" id="offcanvasTop" aria-labelledby="offcanvasTopLabel">
+    <div class="offcanvas offcanvas-end bg-black bg-opacity-50" data-bs-scroll="true" data-bs-backdrop="false" tabindex="-1" id="offcanvasTop" aria-labelledby="offcanvasTopLabel">
         <div class="offcanvas-header">
         {% for series in series_list %}
             <span class="series-block">
@@ -50,7 +50,7 @@
         <div class="offcanvas-body">
 
     <div>
-        <div id="single-dicom-viewer" class="dicom-viewer opacity-100" data-images="" data-annotations=''>
+        <div id="single-dicom-viewer" class="dicom-viewer" data-images="" data-annotations=''>
         </div>
 
     </div>