Group pieces in the hand.

Shogi.UI/Pages/Play/GamePiece.razor.css

@@ -3,9 +3,23 @@
 	height: auto;
 }
 
-[data-upsidedown] {
-	transform: rotateZ(180deg);
-}
 .game-piece {
 	overflow: hidden; /* Because SVGs have weird sizes. */
+	position: relative;
+}
+
+.game-piece .counter {
+	display: grid;
+	place-content: center;
+	position: absolute;
+	top: 0;
+	left: 0;
+	padding: 2px;
+	z-index: 100;
+	background-color: white;
+	border-radius: 9px;
+	border: 1px solid #444;
+	aspect-ratio: 1 / 1;
+	width: 15px;
+	height: 15px;
 }