Refine Streamlit table header styling with targeted CSS selectors

Update table header styling to use more specific CSS selectors, ensuring consistent design across Streamlit DataFrames while maintaining the gold color scheme and hover effects introduced in previous commits

app.py

@@ -102,7 +102,7 @@ st.markdown("""
     }
 
     /* Table header styling */
-    th[role="columnheader"] {
+    .stDataFrame [role="columnheader"] {
         background-color: #FFD700 !important;
         color: white !important;
         font-weight: bold !important;
@@ -112,7 +112,7 @@ st.markdown("""
     }
 
     /* Hover effect for table headers */
-    th[role="columnheader"]:hover {
+    .stDataFrame [role="columnheader"]:hover {
         background-color: #DAA520 !important;
         cursor: pointer;
     }