diff --git a/src/web.rs b/src/web.rs
index aa8cabe..9feb35a 100644
--- a/src/web.rs
+++ b/src/web.rs
@@ -50,9 +50,7 @@ pub async fn index(
         _ => None,
     };
 
-    let groups = leaderboard::build(&state.db, valid_group_id)
-        .await
-        .unwrap_or_default();
+    let groups = Vec::new();
 
     let available_groups = match current.as_ref() {
         Some((id, _)) => futures_groups(&state, *id).await.unwrap_or_default(),
@@ -419,10 +417,12 @@ fn render_index(
 
     if groups.is_empty() {
         html.push_str(
-            r#"<div class="card">Noch keine Landkreisüberquerungen für diese Auswahl.</div>"#,
+            r#"<div id="leaderboard-status" class="card">Landkreisübertritte werden geladen …</div>"#,
         );
     }
 
+    html.push_str(r#"<div id="leaderboard-list"></div><div id="leaderboard-sentinel" aria-hidden="true"></div>"#);
+
     for group in groups {
         html.push_str("<section class=\"card\">");
         html.push_str(&format!(
@@ -711,6 +711,38 @@ document.querySelectorAll('[data-time]').forEach(el=>{
   el.textContent=fmtTime(el.dataset.time);
   el.title=Intl.DateTimeFormat().resolvedOptions().timeZone;
 });
+function escapeHtml(value){return String(value).replace(/[&<>\"']/g,ch=>({'&':'&amp;','<':'&lt;','>':'&gt;','\"':'&quot;',"'":'&#39;'}[ch]));}
+function formatPower(value){return value == null ? '—' : Number(value).toFixed(0)+' W';}
+function formatHr(value){return value == null ? '—' : Number(value).toFixed(0)+' bpm';}
+function leaderboardRowHtml(row){
+  const interval=row.interval_url ? '<a href="'+escapeHtml(row.interval_url)+'" target="_blank" rel="noreferrer">Intervall</a>' : '<span class="small">—</span>';
+  return '<tr><td class="rank">'+row.rank+'</td><td>'+escapeHtml(row.athlete)+'</td><td class="time" data-time="'+escapeHtml(row.crossing_time)+'">'+escapeHtml(row.crossing_time)+'</td><td><a href="'+escapeHtml(row.activity_url)+'">'+escapeHtml(row.activity_id)+'</a></td><td>'+interval+'</td><td>'+formatPower(row.average_watts)+'</td><td>'+formatHr(row.average_heartrate)+'</td><td><div class="mini-map" data-lat="'+row.lat+'" data-lon="'+row.lon+'"></div></td></tr>';
+}
+function leaderboardGroupKey(group){return group.bucket_start+'|'+group.from_county+'|'+group.to_county;}
+function leaderboardGroupHtml(group){return '<section class="card leaderboard-group"><h2>'+escapeHtml(group.from_county)+' → '+escapeHtml(group.to_county)+'</h2><div class="small">10-Minuten-Fenster · '+escapeHtml(group.bucket_start)+' · Standort ±10 m</div><div class="group-map" data-lat="'+group.crossing_lat+'" data-lon="'+group.crossing_lon+'"></div><table><thead><tr><th>#</th><th>Fahrer</th><th>Übertritt</th><th>Aktivität</th><th>Intervall</th><th>Power</th><th>HR</th><th>Karte</th></tr></thead><tbody>'+group.rows.map(leaderboardRowHtml).join('')+'</tbody></table></section>';}
+function initLeaderboardElements(root){
+  root.querySelectorAll('[data-time]').forEach(el=>{el.textContent=fmtTime(el.dataset.time);el.title=Intl.DateTimeFormat().resolvedOptions().timeZone;});
+  root.querySelectorAll('.group-map').forEach(el=>{if(el.dataset.mapReady)return;const lat=Number(el.dataset.lat),lon=Number(el.dataset.lon);if(!Number.isFinite(lat)||!Number.isFinite(lon))return;el.dataset.mapReady='1';const map=L.map(el,{scrollWheelZoom:false}).setView([lat,lon],15);tileLayer(map);L.circle([lat,lon],{radius:10}).addTo(map);L.marker([lat,lon]).addTo(map);});
+  root.querySelectorAll('.mini-map').forEach(el=>{if(el.dataset.mapReady)return;const lat=Number(el.dataset.lat),lon=Number(el.dataset.lon);if(!Number.isFinite(lat)||!Number.isFinite(lon))return;el.dataset.mapReady='1';const map=L.map(el,{zoomControl:false,dragging:false,scrollWheelZoom:false,doubleClickZoom:false,touchZoom:false}).setView([lat,lon],16);tileLayer(map);L.circle([lat,lon],{radius:10}).addTo(map);L.marker([lat,lon]).addTo(map);});
+}
+const leaderboardList=document.getElementById('leaderboard-list');
+if(leaderboardList){
+  const status=document.getElementById('leaderboard-status'),sentinel=document.getElementById('leaderboard-sentinel'),groups=new Map();
+  let offset=0,loading=false,hasMore=true; const pageSize=50;
+  async function loadLeaderboard(){
+    if(loading||!hasMore)return; loading=true;
+    try{
+      const params=new URLSearchParams({offset:String(offset),limit:String(pageSize)}),selected=new URLSearchParams(location.search).get('group_id');
+      if(selected)params.set('group_id',selected);
+      const response=await fetch('/api/leaderboard?'+params,{headers:{Accept:'application/json'}}); if(!response.ok)throw new Error('HTTP '+response.status);
+      const page=await response.json();
+      if(offset===0&&page.groups.length===0){status.textContent='Noch keine Landkreisüberquerungen für diese Auswahl.';status.style.display='block';}else{status.style.display='none';}
+      for(const group of page.groups){const key=leaderboardGroupKey(group),existing=groups.get(key);if(existing){const tbody=existing.querySelector('tbody');tbody.insertAdjacentHTML('beforeend',group.rows.map(leaderboardRowHtml).join(''));initLeaderboardElements(tbody);}else{leaderboardList.insertAdjacentHTML('beforeend',leaderboardGroupHtml(group));const section=leaderboardList.lastElementChild;groups.set(key,section);initLeaderboardElements(section);}}
+      offset=page.next_offset;hasMore=page.has_more;if(!hasMore)sentinel.style.display='none';
+    }catch(error){console.error(error);status.textContent='Landkreisübertritte konnten nicht geladen werden.';status.style.display='block';}finally{loading=false;}
+  }
+  const observer=new IntersectionObserver(entries=>{if(entries.some(entry=>entry.isIntersecting))loadLeaderboard();},{rootMargin:'800px 0px'});observer.observe(sentinel);loadLeaderboard();
+}
 document.querySelectorAll('.group-map').forEach(el=>{
   const lat=Number(el.dataset.lat),lon=Number(el.dataset.lon);
   if(!Number.isFinite(lat)||!Number.isFinite(lon)) return;