Update app.py

app.py

@@ -39,8 +39,7 @@ def _(mo):
 
     # Place as the last statement to ensure Marimo renders it!
     upload_ui
-    return upload_decomp, upload_species, upload_yield
-
+    return upload_decomp, upload_species, upload_yield, upload_ui
 
 @app.cell
 def _(io, mo, pd, upload_decomp, upload_species, upload_yield):
@@ -129,7 +128,39 @@ def _(ALL_SITES, mo, species_data):
 def _(mo):
     dropdown_styles = mo.Html("""
     <style>
-      ... (keep your existing CSS unchanged)
+      .marimo-dropdown select, select {
+        appearance: none;
+        -webkit-appearance: none;
+        background-color: #1e1e2e;
+        color: #cdd6f4;
+        padding: 8px 36px 8px 14px;
+        border: 1.5px solid #45475a;
+        border-radius: 10px;
+        font-size: 13px;
+        font-family: 'Inter', sans-serif;
+        cursor: pointer;
+        min-width: 160px;
+        transition: border-color 0.2s, box-shadow 0.2s;
+        background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24'%3E%3Cpath fill='%2389b4fa' d='M7 10l5 5 5-5z'/%3E%3C/svg%3E");
+        background-repeat: no-repeat;
+        background-position: right 10px center;
+      }
+      select:hover { border-color: #89b4fa; }
+      select:focus {
+        outline: none;
+        border-color: #89b4fa;
+        box-shadow: 0 0 0 3px rgba(137, 180, 250, 0.20);
+      }
+      label {
+        font-size: 11px;
+        font-family: 'Inter', sans-serif;
+        font-weight: 600;
+        letter-spacing: 0.05em;
+        text-transform: uppercase;
+        color: #a6adc8;
+        margin-bottom: 4px;
+        display: block;
+      }
     </style>
     """)