diff --git a/src/pretix/presale/templates/pretixpresale/fragment_modals.html b/src/pretix/presale/templates/pretixpresale/fragment_modals.html
index fce9d0a050..c1ff27d980 100644
--- a/src/pretix/presale/templates/pretixpresale/fragment_modals.html
+++ b/src/pretix/presale/templates/pretixpresale/fragment_modals.html
@@ -49,8 +49,8 @@
     <p class="modal-card-confirm"><button class="btn btn-lg btn-primary">{% trans "Continue" %}</button></p>
 {% enddialog %}
 
-<dialog id="lightbox-dialog" role="alertdialog" aria-labelledby="lightbox-label">
-    <form method="dialog" class="modal-card">
+<dialog id="lightbox-dialog" class="modal-card" role="alertdialog" aria-labelledby="lightbox-label">
+    <form method="dialog" class="modal-card-inner form-horizontal">
         <div class="modal-card-content">
             <figure class="text-center text-muted">
                 <img />
diff --git a/src/pretix/static/pretixbase/scss/_dialogs.scss b/src/pretix/static/pretixbase/scss/_dialogs.scss
index 33d11145ce..3812cae33a 100644
--- a/src/pretix/static/pretixbase/scss/_dialogs.scss
+++ b/src/pretix/static/pretixbase/scss/_dialogs.scss
@@ -172,3 +172,25 @@ body.has-modal-dialog .container, body.has-modal-dialog #wrapper {
         color: $brand-primary;
     }
 }
+
+#lightbox-dialog {
+  width: fit-content;
+  max-width: 80%;
+  min-width: 24em;
+  .modal-card-content {
+    padding: 2.5em;
+  }
+
+  img {
+    max-width: 100%;
+  }
+
+  button {
+    position: absolute;
+    top: 1em;
+    right: 1em;
+  }
+  figcaption {
+    margin-top: 1em;
+  }
+}