fix #2207

Closes #2207

Merge request studip/studip!1804

resources/assets/stylesheets/scss/courseware.scss

@@ -4800,13 +4800,14 @@ cw tiles
             background: none;
 
             progress {
+                appearance: none;
                 display: block;
                 width: 100%;
                 height: 3px;
                 margin: 0;
                 border: none;
                 background: rgba(0,0,0,0.3);
-                &:-webkit-progress-bar {
+                &::-webkit-progress-bar {
                     background:  rgba(0,0,0,0.3);
                 }
                 &::-webkit-progress-value {

resources/vue/components/courseware/CoursewareUnitItem.vue

 <template>
-    <div class="courseware-unit-item">
+    <li class="courseware-unit-item">
         <courseware-tile
-            tag="li"
+            tag="div"
             :color="color"
             :title="title"
             :descriptionLink="url"
@@ -54,7 +54,7 @@
 
         <courseware-unit-item-dialog-export v-if="showExportDialog" :unit="unit" @close="showExportDialog = false" />
         <courseware-unit-item-dialog-settings v-if="showSettingsDialog" :unit="unit" @close="closeSettingsDialog"/>
-    </div>
+    </li>
 </template>
 
 <script>
@@ -181,4 +181,4 @@ export default {
             this.companionSuccess({ info: this.$gettext('Lernmaterial kopiert.') });        }
     }
 }
-</script>
\ No newline at end of file
+</script>