...

Chrono/Model/CardData.cs

@@ -31,4 +31,14 @@ public class CardData
     public bool HasImmortalize => ImmortalizeTo is { Count: > 0 };
     public bool IsImmortalized => ImmortalizeFrom != null;
     public string ImagePath => $"cards/{ImageFile ?? "placeholder.png"}";
+
+    public bool MatchesSearch(string query)
+    {
+        if (string.IsNullOrWhiteSpace(query)) return true;
+        var q = query.Trim().ToLowerInvariant();
+        return Name.ToLowerInvariant().Contains(q) ||
+               (Description?.ToLowerInvariant().Contains(q) ?? false) ||
+               (Faction?.ToLowerInvariant().Contains(q) ?? false) ||
+               Archetypes.Any(a => a.ToLowerInvariant().Contains(q));
+    }
 }

Chrono/Model/CardNote.cs

@@ -4,4 +4,4 @@ public class CardNote
 {
     public string CardName { get; set; } = "";
     public string Note { get; set; } = "";
-}
+}

Chrono/Model/DeckData.cs

@@ -9,4 +9,14 @@ public class DeckData
     public string? Description { get; init; }
     public List<string> Factions { get; init; } = [];
     public bool IsVisible { get; init; }
-}
+
+    public bool IsValid => Cards.Count == 40 && Divers.Count <= 2;
+
+    public string ValidationMessage => (Cards.Count, Divers.Count) switch
+    {
+        (< 40, _) => $"Deck needs {40 - Cards.Count} more cards.",
+        (> 40, _) => $"Deck has {Cards.Count - 40} too many cards.",
+        (_, > 2) => "Deck can only have 2 Divers.",
+        _ => "Deck is valid."
+    };
+}