fix bug: en version model card download

tabs/leaderboard_v1_en.py

@@ -2325,18 +2325,18 @@ def create_leaderboard_v2_tab():
         )
         download_card_btn = gr.Button(
             "Download as PNG",
-            elem_id="download-card-btn",
+            elem_id="download-card-btn-en",
             elem_classes=["pill-button"]
         )
     
     gr.HTML("""
-            <div class="performance-card-display" id="card-display-container">
+            <div class="performance-card-display" id="card-display-container-en">
     """)
     
     # Card display area - generate initial card
     initial_model = initial_df['Model'].tolist()[0] if len(initial_df) > 0 else None
     initial_card_html = generate_performance_card(initial_model) if initial_model else ""
-    card_display = gr.HTML(value=initial_card_html, elem_id="performance-card-html")
+    card_display = gr.HTML(value=initial_card_html, elem_id="performance-card-html-en")
     
     gr.HTML("""
             </div>
@@ -3130,13 +3130,14 @@ def create_leaderboard_v2_tab():
             const pause = (ms) => new Promise(resolve => setTimeout(resolve, ms));
             await pause(60);
             
-            const card = document.querySelector('.performance-card');
-            if (!card) {
+            const container = document.getElementById('performance-card-html-en');
+            const card = container?.querySelector('.performance-card');
+            if (!container || !card) {
                 alert('Performance card not found. Please select a model first.');
                 return;
             }
             
-            const btn = document.getElementById('download-card-btn');
+            const btn = document.getElementById('download-card-btn-en');
             const originalText = btn?.textContent || '';
             if (btn) {
                 btn.textContent = 'Generating...';
@@ -3156,12 +3157,20 @@ def create_leaderboard_v2_tab():
                     useCORS: true
                 });
                 
+                if (!canvas || !canvas.width || !canvas.height) {
+                    throw new Error('Captured canvas is empty');
+                }
+                
                 const link = document.createElement('a');
                 const modelName = card.querySelector('.card-model-name')?.textContent || 'model';
                 const timestamp = new Date().toISOString().slice(0, 10);
                 const fileName = `${modelName.replace(/[^a-z0-9]/gi, '-').toLowerCase()}-performance-${timestamp}.png`;
                 link.download = fileName;
-                link.href = canvas.toDataURL('image/png');
+                const dataUrl = canvas.toDataURL('image/png');
+                if (!dataUrl || dataUrl === 'data:,' || dataUrl.length <= 'data:image/png;base64,'.length) {
+                    throw new Error('Failed to generate PNG data');
+                }
+                link.href = dataUrl;
                 document.body.appendChild(link);
                 link.click();
                 document.body.removeChild(link);