Improve contest management view

app/views/contests/index.html.slim

@@ -1,16 +1,23 @@
-h4.mb-3 Manage your contests
-
+.row
+  .col
+    h4.mb-3
+      | Manage your contests
+      .float-end
         a.btn.btn-primary.mb-4 href=new_contest_path
           | Create a new contest
 
 .row.row-cols-1.row-cols-md-3.g-4
   - @contests.each do |contest|
     .col
+      css:
+        .card:hover { background-color: lightblue; }
       .card.h-100
         .card-header
           = contest.name
         .card-body
-          p.card-text
-            | Description text comes here.
-          a.btn.btn-primary href=contest_path(contest)
-            | Open
+          .row
+            - contest.puzzles.each do |puzzle|
+              - if puzzle.image.attached?
+                .col
+                  = image_tag puzzle.image, style: "max-height: 80px;"
+          a.stretched-link href=contest_path(contest)