diff --git a/assets/css/_promotion.css b/assets/css/_promotion.css
index ef7f315..db0d660 100644
--- a/assets/css/_promotion.css
+++ b/assets/css/_promotion.css
@@ -8,6 +8,7 @@
   z-index: 100;
   border-radius: inherit;
 }
+
 .promotion-picker {
   display: flex;
   flex-direction: column;
@@ -15,26 +16,60 @@
   background: white;
   padding: 10px;
   border-radius: 14px;
-  box-shadow: 0 8px 32px rgba(0,0,0,0.35);
+  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
 }
+
 .promotion-piece {
-  width: 64px;
-  height: 64px;
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  font-size: 42px;
+  width: 80px;
+  height: 80px;
   cursor: pointer;
   border: 2px solid transparent;
   border-radius: 8px;
-  background: #fafafa;
+  background-color: #fafafa;
+  background-size: 80% 80%;
+  background-position: center;
+  background-repeat: no-repeat;
   transition: all 0.15s ease;
 }
+
 .promotion-piece:hover {
-  background: #eff6ff;
+  background-color: #eff6ff;
   border-color: #3b82f6;
   transform: scale(1.08);
 }
+
 .promotion-piece:active {
   transform: scale(0.95);
-}
\ No newline at end of file
+}
+
+.promotion-piece.queen.white {
+  background-image: url('data:image/svg+xml;base64,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');
+}
+
+.promotion-piece.rook.white {
+  background-image: url('data:image/svg+xml;base64,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');
+}
+
+.promotion-piece.bishop.white {
+  background-image: url('data:image/svg+xml;base64,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');
+}
+
+.promotion-piece.knight.white {
+  background-image: url('data:image/svg+xml;base64,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');
+}
+
+.promotion-piece.queen.black {
+  background-image: url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI0NSIgaGVpZ2h0PSI0NSI+PGcgZmlsbC1ydWxlPSJldmVub2RkIiBzdHJva2U9IiMwMDAiIHN0cm9rZS13aWR0aD0iMS41IiBzdHJva2UtbGluZWNhcD0icm91bmQiIHN0cm9rZS1saW5lam9pbj0icm91bmQiPjxnIHN0cm9rZT0ibm9uZSI+PGNpcmNsZSBjeD0iNiIgY3k9IjEyIiByPSIyLjc1Ii8+PGNpcmNsZSBjeD0iMTQiIGN5PSI5IiByPSIyLjc1Ii8+PGNpcmNsZSBjeD0iMjIuNSIgY3k9IjgiIHI9IjIuNzUiLz48Y2lyY2xlIGN4PSIzMSIgY3k9IjkiIHI9IjIuNzUiLz48Y2lyY2xlIGN4PSIzOSIgY3k9IjEyIiByPSIyLjc1Ii8+PC9nPjxwYXRoIGQ9Ik05IDI2YzguNS0xLjUgMjEtMS41IDI3IDBsMi41LTEyLjVMMzEgMjVsLS4zLTE0LjEtNS4yIDEzLjYtMy0xNC41LTMgMTQuNS01LjItMTMuNkwxNCAyNSA2LjUgMTMuNSA5IDI2eiIgc3Ryb2tlLWxpbmVjYXA9ImJ1dHQiLz48cGF0aCBkPSJNOSAyNmMwIDIgMS41IDIgMi41IDQgMSAxLjUgMSAxIC41IDMuNS0xLjUgMS0xLjUgMi41LTEuNSAyLjUtMS41IDEuNS41IDIuNS41IDIuNSA2LjUgMSAxNi41IDEgMjMgMCAwIDAgMS41LTEgMC0yLjUgMCAwIC41LTEuNS0xLTIuNS0uNS0yLjUtLjUtMiAuNS0zLjUgMS0yIDIuNS0yIDIuNS00LTguNS0xLjUtMTguNS0xLjUtMjcgMHoiIHN0cm9rZS1saW5lY2FwPSJidXR0Ii8+PHBhdGggZD0iTTExIDM4LjVhMzUgMzUgMSAwIDAgMjMgMCIgZmlsbD0ibm9uZSIgc3Ryb2tlLWxpbmVjYXA9ImJ1dHQiLz48cGF0aCBkPSJNMTEgMjlhMzUgMzUgMSAwIDEgMjMgMG0tMjEuNSAyLjVoMjBtLTIxIDNhMzUgMzUgMSAwIDAgMjIgMG0tMjMgM2EzNSAzNSAxIDAgMCAyNCAwIiBmaWxsPSJub25lIiBzdHJva2U9IiNlY2VjZWMiLz48L2c+PC9zdmc+');
+}
+
+.promotion-piece.rook.black {
+  background-image: url('data:image/svg+xml;base64,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');
+}
+
+.promotion-piece.bishop.black {
+  background-image: url('data:image/svg+xml;base64,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');
+}
+
+.promotion-piece.knight.black {
+  background-image: url('data:image/svg+xml;base64,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');
+}
diff --git a/assets/js/hooks/chessBoard.js b/assets/js/hooks/chessBoard.js
index 9af25b2..011519a 100644
--- a/assets/js/hooks/chessBoard.js
+++ b/assets/js/hooks/chessBoard.js
@@ -51,21 +51,6 @@ export const ChessBoard = {
     return dests;
   },
 
-//   handleMove(orig, dest) {
-//     const { role, color } = this.ground.state.pieces.get(dest);
-//     const destRank = dest.split("").pop()
-
-//     const isPromotion = this.isPromotion(role, destRank)
-
-//     if (isPromotion) {
-//         this.showPromotionDialog()
-//         this.executeMove(orig, dest, "q");
-//         return
-//     }
-
-//     this.executeMove(orig, dest, "q");
-//   },
-
 handleMove(orig, dest) {
     const piece = this.ground.state.pieces.get(dest);
     const destRank = dest[1];
@@ -76,12 +61,7 @@ handleMove(orig, dest) {
     this.executeMove(orig, dest);
   },
 
-  isPromotion(piece, rank) {
-    return piece === "pawn" && (rank === "1" || rank === "8");
-  },
-
   showPromotionDialog(orig, dest) {
-    console.log("trigger promotion dialog");
     this.pendingPromotion = { orig, dest };
     const color = this.chess.turn() === 'w' ? 'white' : 'black';
     const overlay = document.createElement('div');
@@ -89,18 +69,15 @@ handleMove(orig, dest) {
     const picker = document.createElement('div');
     picker.className = 'promotion-picker';
     const pieces = [
-      { type: 'queen',  symbol: { white: '♕', black: '♛' } },
-      { type: 'rook',   symbol: { white: '♖', black: '♜' } },
-      { type: 'bishop', symbol: { white: '♗', black: '♝' } },
-      { type: 'knight', symbol: { white: '♘', black: '♞' } },
+      { type: 'queen',  code: 'q' },
+      { type: 'rook',   code: 'r' },
+      { type: 'bishop', code: 'b' },
+      { type: 'knight', code: 'n' },
     ];
-    // chess.js promotion codes
-    const code = { queen: 'q', rook: 'r', bishop: 'b', knight: 'n' };
-    pieces.forEach(({ type, symbol }) => {
+    pieces.forEach(({ type, code }) => {
       const btn = document.createElement('button');
-      btn.className = 'promotion-piece';
-      btn.textContent = symbol[color];
-      btn.addEventListener('click', () => this.completePromotion(code[type]));
+      btn.className = `promotion-piece ${type} ${color}`;
+      btn.addEventListener('click', () => this.completePromotion(code));
       picker.appendChild(btn);
     });
     overlay.appendChild(picker);
diff --git a/test/chesstrainer_web/controllers/error_html_test.exs b/test/chesstrainer_web/controllers/error_html_test.exs
index a45c950..594ac85 100644
--- a/test/chesstrainer_web/controllers/error_html_test.exs
+++ b/test/chesstrainer_web/controllers/error_html_test.exs
@@ -9,6 +9,7 @@ defmodule ChesstrainerWeb.ErrorHTMLTest do
   end
 
   test "renders 500.html" do
-    assert render_to_string(ChesstrainerWeb.ErrorHTML, "500", "html", []) == "Internal Server Error"
+    assert render_to_string(ChesstrainerWeb.ErrorHTML, "500", "html", []) ==
+             "Internal Server Error"
   end
 end