diff --git a/web/static/index.html b/web/static/index.html
index b2412e75..8218842f 100644
--- a/web/static/index.html
+++ b/web/static/index.html
@@ -189,6 +189,22 @@
         </div>
     </div>
 
+    <!-- ── History Chart Modal ── -->
+    <div id="historyModal" class="modal-overlay hidden">
+        <div class="modal-content">
+            <div class="modal-header">
+                <h2>📊 <span id="historyModalTitle">历史准确率</span></h2>
+                <button class="modal-close" id="historyModalClose">✕</button>
+            </div>
+            <div class="modal-body">
+                <div class="history-stats" id="historyStats"></div>
+                <div class="history-chart-wrapper">
+                    <canvas id="historyChart"></canvas>
+                </div>
+            </div>
+        </div>
+    </div>
+
     <!-- Leaflet JS -->
     <script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
     <!-- Chart.js -->