Miscellaneous styling fixes (#1374)

* Fixing up modal and cover selector

* adding code for card image

* fixing placeholder border

* Fixing placeholder issue

* Fixing drop down z-index

* Updating reading list

UI/Web/src/app/cards/_modals/edit-series-modal/edit-series-modal.component.html

@@ -1,4 +1,4 @@
-<div *ngIf="series !== undefined">
+<div class="modal-container" *ngIf="series !== undefined">
     <div class="modal-header">
         <h4 class="modal-title">
             {{this.series.name}} Details</h4>

UI/Web/src/app/cards/_modals/edit-series-modal/edit-series-modal.component.scss

@@ -1,5 +1,5 @@
 .scrollable-modal {
-    max-height: 90vh; // 600px
+    max-height: calc(var(--vh) * 100 - 198px); // 600px
     overflow: auto;
 }
 
@@ -8,4 +8,4 @@
         background-color: var(--primary-color);
         color: white;
     }
-}
+}