Fix family navigation and compact landing page

app.py

@@ -29,6 +29,7 @@ DATA_DIR = SPACE_ROOT / "data"
 DATA_DIR.mkdir(parents=True, exist_ok=True)
 HYDRATE_STATUS = maybe_hydrate_from_dataset(DATA_DIR)
 STORE = SolutionStore(DATA_DIR)
+FAMILY_PROMPT = "Select a family..."
 
 
 CSS = """
@@ -91,7 +92,7 @@ gradio-app,
 }
 
 .packing-shell {
-  min-height: 100vh;
+  min-height: 0;
   background: var(--page);
   color: var(--ink);
   font-family: Helvetica, Arial, sans-serif !important;
@@ -1168,9 +1169,7 @@ def top_nav() -> str:
 
 
 def directory_html() -> str:
-    summaries = [setup_summary(setup) for setup in setup_choices()]
-    coordinates = coordinate_records_by_case()
-    family_cards = "".join(family_card(summary, coordinates) for summary in summaries)
+    choices = setup_choices()
     return f"""
     <main class="packing-shell" id="top">
       <section class="hero-stage">
@@ -1183,6 +1182,7 @@ def directory_html() -> str:
               Friedman rows keep their credited finder; rendered cards report our verified coordinate metric and
               mark unrecovered references in orange.
             </p>
+            <p class="hero-stats">{len(choices)} supported families. Choose one below to load its records.</p>
           </div>
         </div>
       </section>
@@ -1193,11 +1193,10 @@ def directory_html() -> str:
             <div>
               <h2>Choose a family</h2>
               <p class="section-note">
-                Use the Family Records page to open a family. Each tile previews the n=10 rendering for that setup.
+                Use the selector below. Records load only after a family is selected, so the front page stays short.
               </p>
             </div>
           </div>
-          <div class="family-grid">{family_cards}</div>
         </div>
       </section>
     </main>
@@ -1208,6 +1207,20 @@ def browse_html() -> str:
     return directory_html()
 
 
+def empty_family_html() -> str:
+    return """
+    <main class="packing-shell">
+      <section class="section">
+        <div class="contain">
+          <div class="page-card">
+            <p>Select a family to view verified coordinate renderings and record details.</p>
+          </div>
+        </div>
+      </section>
+    </main>
+    """
+
+
 def leaderboard_html() -> str:
     rows: dict[str, dict[str, Any]] = {}
     coordinates = coordinate_records_by_case()
@@ -1360,6 +1373,8 @@ def submit_solution(
 
 
 def update_family_page(setup: str):
+    if not setup or setup == FAMILY_PROMPT:
+        return empty_family_html()
     return family_page_html(setup)
 
 
@@ -1370,17 +1385,23 @@ with gr.Blocks(title="Packing Benchmark") as demo:
     with gr.Tabs():
         with gr.Tab("Families"):
             browse_page = gr.HTML(directory_html())
+            home_family_select = gr.Dropdown(
+                choices=[FAMILY_PROMPT, *setup_choices()],
+                value=FAMILY_PROMPT,
+                label="Family",
+                elem_id="home-family-selector",
+            )
+            home_family_page = gr.HTML(empty_family_html())
 
         with gr.Tab("Family Records"):
             choices = setup_choices()
-            initial_setup = choices[0] if choices else ""
             family_select = gr.Dropdown(
-                choices=choices,
-                value=initial_setup,
+                choices=[FAMILY_PROMPT, *choices],
+                value=FAMILY_PROMPT,
                 label="Family",
                 elem_id="family-selector",
             )
-            family_page = gr.HTML(family_page_html(initial_setup))
+            family_page = gr.HTML(empty_family_html())
 
         with gr.Tab("Leaderboard"):
             leaderboard_page = gr.HTML(leaderboard_html())
@@ -1404,6 +1425,7 @@ with gr.Blocks(title="Packing Benchmark") as demo:
                         preview = gr.HTML(label="Browser render")
                 normalized_json = gr.Code(label="Normalized JSON", language="json", lines=10)
 
+    home_family_select.change(update_family_page, inputs=[home_family_select], outputs=[home_family_page])
     family_select.change(update_family_page, inputs=[family_select], outputs=[family_page])
     verify_btn.click(verify_only, inputs=[json_code, json_file, tolerance], outputs=[report, preview, normalized_json])
     submit_btn.click(