fix: unify example buttons, set button text white, simplify tab selected style

app.py

@@ -333,14 +333,14 @@ ul.options, .gr-dropdown-options {
 }
 
 .gr-button-secondary {
-    background: #f1f5f9 !important; /* clearer separation from page background */
-    border: 1px solid #cbd5e1 !important;
-    color: #0f172a !important;
+    background: #64748b !important;
+    border: 1px solid #64748b !important;
+    color: #ffffff !important;
     box-shadow: 0 4px 10px rgba(15, 23, 42, 0.08) !important;
 }
 .gr-button-secondary:hover {
-    background: #e2e8f0 !important;
-    border-color: #94a3b8 !important;
+    background: #475569 !important;
+    border-color: #475569 !important;
 }
 
 /* Tabs */
@@ -352,8 +352,9 @@ ul.options, .gr-dropdown-options {
 .tabs button.selected {
     color: #ffffff !important;
     background: var(--accent) !important;
-    border-radius: 6px !important;
+    border-radius: 0 !important;
     padding: 4px 10px !important;
+    border-bottom: none !important;
 }
 
 /* Radio buttons */
@@ -406,7 +407,7 @@ with gr.Blocks(title="UltraData-Math L3 Generator", css=custom_css, theme=gr.the
                             info="Select the target audience level"
                         )
                         with gr.Row():
-                            qa_example_btn = gr.Button("📋 Load Example", variant="secondary")
+                            qa_example_btn = gr.Button("Generate", variant="secondary")
                             qa_btn = gr.Button("🚀 Generate Q&A", variant="primary")
                     
                     with gr.Column(scale=1):
@@ -442,7 +443,7 @@ with gr.Blocks(title="UltraData-Math L3 Generator", css=custom_css, theme=gr.the
                             info="Choose the persona and tone of the conversation"
                         )
                         with gr.Row():
-                            conv_example_btn = gr.Button("📋 Load Example", variant="secondary")
+                            conv_example_btn = gr.Button("Generate", variant="secondary")
                             conv_btn = gr.Button("🚀 Generate Conversation", variant="primary")
                     
                     with gr.Column(scale=1):
@@ -477,7 +478,7 @@ with gr.Blocks(title="UltraData-Math L3 Generator", css=custom_css, theme=gr.the
                             info="Select the desired output style"
                         )
                         with gr.Row():
-                            rewrite_example_btn = gr.Button("📋 Load Example", variant="secondary")
+                            rewrite_example_btn = gr.Button("Generate", variant="secondary")
                             rewrite_btn = gr.Button("🚀 Rewrite Content", variant="primary")
                     
                     with gr.Column(scale=1):
@@ -506,7 +507,7 @@ with gr.Blocks(title="UltraData-Math L3 Generator", css=custom_css, theme=gr.the
                             lines=12,
                         )
                         with gr.Row():
-                            know_example_btn = gr.Button("📋 Load Example", variant="secondary")
+                            know_example_btn = gr.Button("Generate", variant="secondary")
                             know_btn = gr.Button("🚀 Extract Knowledge", variant="primary")
                     
                     with gr.Column(scale=1):
@@ -541,7 +542,7 @@ with gr.Blocks(title="UltraData-Math L3 Generator", css=custom_css, theme=gr.the
                             info="Select the problem difficulty"
                         )
                         with gr.Row():
-                            textbook_example_btn = gr.Button("📋 Load Example", variant="secondary")
+                            textbook_example_btn = gr.Button("Generate", variant="secondary")
                             textbook_btn = gr.Button("🚀 Generate Exercise", variant="primary")
                     
                     with gr.Column(scale=1):