Somewhat improve appearance of album cards on narrow screens.

Previously, on very narrow screens, the album cards were spilling
out of the container. Now they are better contained but I am
still not 100% satisfied with the margins between them.

frontends/etiquette_flask/static/css/photo_card.css

@@ -26,8 +26,11 @@
         "thumbnail metadata" auto
         /auto      1fr;
 
-    width: 325px;
-    margin: 8px;
+    max-width: 325px;
+    width: 100%;
+    margin-right: 8px;
+    margin-bottom: 8px;
+    box-sizing: border-box;
     padding: 8px;
 }
 .album_card_thumbnail

frontends/etiquette_flask/templates/album.html

@@ -56,6 +56,10 @@ h2, h3
             "right" 150px
             /1fr;
     }
+    #left
+    {
+        margin-right: unset;
+    }
     #right
     {
         top: unset !important;