diff --git a/viewer/index.html b/viewer/index.html
index 7b02e57..2e2e547 100644
--- a/viewer/index.html
+++ b/viewer/index.html
@@ -12,8 +12,9 @@
     height: 100vh; overflow: hidden;
     font-family: monospace; background: #1a1a2e; color: #e0e0e0;
     display: grid;
-    grid-template-rows: 36px 40px minmax(200px, 1fr) 54px 1fr;
+    grid-template-rows: 36px 40px minmax(200px, 1fr) 54px 28px 1fr;
   }
+  .hidden { display: none !important; }
   /* Row 0: datebar */
   #datebar {
     background: #0d0d20; border-bottom: 1px solid #0f3460;
@@ -45,7 +46,7 @@
   }
   #title { font-size: 13px; font-weight: bold; color: #e94560; white-space: nowrap; }
   #stats { font-size: 11px; color: #a0c4ff; flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
-  #layer-toggles { display: flex; gap: 6px; align-items: center; flex-shrink: 0; }
+  #layer-toggles { display: none; }
   .layer-btn {
     font-family: monospace; font-size: 10px; padding: 2px 7px; cursor: pointer;
     border-radius: 2px; border: 1px solid; background: transparent;
@@ -60,6 +61,20 @@
   /* Row 2: map */
   #map { position: relative; min-height: 0; }
 
+  /* No-data overlay */
+  #no-data-overlay {
+    position: absolute; inset: 0; z-index: 2000;
+    background: rgba(10,10,26,0.82);
+    display: flex; align-items: center; justify-content: center;
+    pointer-events: none;
+  }
+  #no-data-overlay.hidden { display: none; }
+  #no-data-overlay .nodata-msg {
+    font-size: 18px; color: #555; font-family: monospace; text-align: center;
+    border: 1px solid #1a1a3e; padding: 20px 32px; background: #0a0a1a;
+    pointer-events: none;
+  }
+
   /* USBL panel over map */
   #usbl-panel {
     position: absolute; top: 10px; left: 50px; z-index: 1000;
@@ -73,6 +88,11 @@
     display: inline-block; background: #ff8800; color: #1a1a2e;
     font-size: 9px; font-weight: bold; padding: 1px 4px; border-radius: 2px; margin-top: 4px;
   }
+  /* layer toggles bottom-right on map */
+  #map-layer-toggles {
+    position: absolute; bottom: 10px; right: 10px; z-index: 1000;
+    display: flex; flex-direction: column; gap: 4px; align-items: flex-end;
+  }
   /* legend over map */
   #legend {
     position: absolute; bottom: 10px; left: 10px; z-index: 1000;
@@ -146,6 +166,21 @@
   .chart-wrap .plotly-wrap { flex: 1; min-height: 0; position: relative; }
   .chart-wrap .plotly-wrap > div { width: 100% !important; height: 100% !important; }
 
+  /* Tab navigation */
+  #panels-tabs {
+    background: #0d0d20; border-top: 1px solid #0f3460; border-bottom: 1px solid #0f3460;
+    display: flex; gap: 0; flex-shrink: 0;
+  }
+  .panel-tab {
+    font-family: monospace; font-size: 11px; padding: 6px 16px; cursor: pointer;
+    border: none; border-right: 1px solid #0f3460; background: transparent;
+    color: #666;
+  }
+  .panel-tab.active { background: #16213e; color: #e0e0e0; }
+  .panel-tab:hover:not(.active) { background: #0f3460; color: #a0c4ff; }
+  .panel-section { display: none; }
+  .panel-section.active { display: block; }
+
   /* Pipeline overlay */
   #pipeline-overlay {
     display: none;
@@ -218,8 +253,8 @@
 <div id="datebar">
   <input type="date" id="date-picker">
   <button id="btn-today" onclick="datePickerToday()">Aujourd'hui</button>
-  <span id="mission-label" class="no-data">Chargement...</span>
-  <span id="load-status"></span>
+  <span id="mission-label" class="no-data">—</span>
+  <span id="load-status" style="font-size:10px;color:#888;font-style:italic;flex:1;"></span>
   <button id="btn-pipeline" onclick="togglePipeline()">Pipeline</button>
 </div>
 
@@ -272,20 +307,24 @@ flowchart LR
 <!-- Row 1: Header -->
 <div id="header">
   <span id="title">COSMA NAV v6</span>
-  <span id="stats">Chargement...</span>
-  <div id="layer-toggles">
-    <button class="layer-btn active" id="btn-usv"  onclick="toggleLayer('usv')">USV</button>
-    <button class="layer-btn active" id="btn-auv"  onclick="toggleLayer('auv')">AUV</button>
-    <button class="layer-btn active" id="btn-vec"  onclick="toggleLayer('vec')">USBL vec</button>
-    <button class="layer-btn active" id="btn-usbl-panel" onclick="toggleLayer('panel')">Stats</button>
-  </div>
-  <select id="sortie-select"><option value="">— Sortie —</option></select>
+  <span id="stats" style="flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:11px;color:#a0c4ff;"></span>
+  <select id="sortie-select"><option value="">Chargement Gdrive (~30s)...</option></select>
+  <span id="mission-label-header" style="font-size:11px;font-family:monospace;padding:2px 8px;color:#555;white-space:nowrap;"></span>
   <button id="btn-sync" disabled>Sync &amp; Process</button>
   <span id="sync-progress"></span>
 </div>
 
 <!-- Row 2: Map -->
 <div id="map">
+  <div id="no-data-overlay">
+    <div class="nodata-msg">⬇ Sélectionnez une sortie pour charger les données</div>
+  </div>
+  <div id="map-layer-toggles">
+    <button class="layer-btn active" id="btn-usv"  onclick="toggleLayer('usv')">⛵ USV</button>
+    <button class="layer-btn active" id="btn-auv"  onclick="toggleLayer('auv')">🛥 AUV</button>
+    <button class="layer-btn active" id="btn-vec"  onclick="toggleLayer('vec')">USBL vec</button>
+    <button class="layer-btn active" id="btn-usbl-panel" onclick="toggleLayer('panel')">Stats</button>
+  </div>
   <div id="legend"></div>
   <div id="usbl-panel">
     <div class="uprow"><span class="uplabel">Dist</span><span class="upval" id="up-dist">—</span></div>
@@ -299,10 +338,10 @@ flowchart LR
 <!-- Row 3: Controls -->
 <div id="controls">
   <div id="ctrl-row1">
-    <span id="ctrl-label">t</span>
+    <span id="ctrl-label" style="font-size:10px;color:#666;white-space:nowrap;">Heure:</span>
     <div id="cursor-slider-wrap"><div id="cursor-slider"></div></div>
-    <span id="cursor-time">—</span>
-    <label for="trail-select">trail</label>
+    <span id="cursor-time" style="font-size:11px;color:#e0e0e0;white-space:nowrap;min-width:70px;">—</span>
+    <label for="trail-select" style="font-size:10px;color:#666;white-space:nowrap;">Trail:</label>
     <select id="trail-select">
       <option value="10000">10s</option>
       <option value="30000">30s</option>
@@ -314,7 +353,7 @@ flowchart LR
     </select>
     <button id="btn-viewall" onclick="viewAll()">View all</button>
     <button id="btn-play">▶</button>
-    <label for="window-select" style="font-size:10px;color:#666;white-space:nowrap;">win</label>
+    <label for="window-select" style="font-size:10px;color:#666;white-space:nowrap;">Window:</label>
     <select id="window-select" style="background:#0f3460;border:1px solid #a855f7;color:#a855f7;font-family:monospace;font-size:11px;padding:2px 6px;border-radius:2px;cursor:pointer;">
       <option value="10000">10s</option>
       <option value="30000">30s</option>
@@ -329,51 +368,62 @@ flowchart LR
   </div>
 </div>
 
-<!-- Row 4: 2×2 Plotly charts -->
+<!-- Row 4: tabs + panels -->
+<div id="panels-tabs">
+  <button class="panel-tab active" onclick="switchTab('charts')">🗺 Charts globaux</button>
+  <button class="panel-tab" onclick="switchTab('usv')">⛵ USV</button>
+  <button class="panel-tab" onclick="switchTab('auv')">🛥 AUV <span id="auv-tabs"></span></button>
+</div>
 <div id="graphs-section">
-  <div id="charts-4grid">
-    <div class="chart-wrap">
-      <div class="chart-title">Depth AUV (m)</div>
-      <div class="plotly-wrap"><div id="chart-depth"></div></div>
-    </div>
-    <div class="chart-wrap">
-      <div class="chart-title">Motors AUV (PWM)</div>
-      <div class="plotly-wrap"><div id="chart-pwm-auv"></div></div>
-    </div>
-    <div class="chart-wrap">
-      <div class="chart-title">Motors USV (PWM)</div>
-      <div class="plotly-wrap"><div id="chart-pwm-usv"></div></div>
-    </div>
-    <div class="chart-wrap">
-      <div class="chart-title">USBL Distance (m)</div>
-      <div class="plotly-wrap"><div id="chart-usbl"></div></div>
+  <!-- Tab: Charts globaux -->
+  <div id="panel-charts" class="panel-section active">
+    <div id="charts-4grid">
+      <div class="chart-wrap">
+        <div class="chart-title">Depth AUV (m)</div>
+        <div class="plotly-wrap"><div id="chart-depth"></div></div>
+      </div>
+      <div class="chart-wrap">
+        <div class="chart-title">Motors AUV (PWM)</div>
+        <div class="plotly-wrap"><div id="chart-pwm-auv"></div></div>
+      </div>
+      <div class="chart-wrap">
+        <div class="chart-title">Motors USV (PWM)</div>
+        <div class="plotly-wrap"><div id="chart-pwm-usv"></div></div>
+      </div>
+      <div class="chart-wrap">
+        <div class="chart-title">USBL Distance (m)</div>
+        <div class="plotly-wrap"><div id="chart-usbl"></div></div>
+      </div>
     </div>
   </div>
-  <div class="panel-header">USV</div>
-  <div class="graphs-grid" id="usv-graphs">
-    <div class="graph-cell" id="usv-yaw"></div>
-    <div class="graph-cell" id="usv-heading"></div>
-    <div class="graph-cell" id="usv-batt"></div>
-    <div class="graph-cell" id="usv-gps"></div>
-    <div class="graph-cell" id="usv-usbl-dist"></div>
-    <div class="graph-cell" id="usv-usbl-angle"></div>
-    <div class="graph-cell wide" id="usv-motors"></div>
-    <div class="graph-cell wide" id="usv-status"></div>
+  <!-- Tab: USV -->
+  <div id="panel-usv" class="panel-section hidden">
+    <div class="panel-header">⛵ USV</div>
+    <div class="graphs-grid" id="usv-graphs">
+      <div class="graph-cell" id="usv-yaw"></div>
+      <div class="graph-cell" id="usv-heading"></div>
+      <div class="graph-cell" id="usv-batt"></div>
+      <div class="graph-cell" id="usv-gps"></div>
+      <div class="graph-cell" id="usv-usbl-dist"></div>
+      <div class="graph-cell" id="usv-usbl-angle"></div>
+      <div class="graph-cell wide" id="usv-motors"></div>
+      <div class="graph-cell wide" id="usv-status"></div>
+    </div>
   </div>
-  <div class="panel-header" id="auv-panel-header">
-    AUV
-    <span id="auv-tabs"></span>
-  </div>
-  <div class="graphs-grid" id="auv-graphs">
-    <div class="graph-cell" id="auv-pry"></div>
-    <div class="graph-cell" id="auv-depth"></div>
-    <div class="graph-cell" id="auv-alt"></div>
-    <div class="graph-cell" id="auv-obs"></div>
-    <div class="graph-cell" id="auv-usbl-dist"></div>
-    <div class="graph-cell" id="auv-usbl-angle"></div>
-    <div class="graph-cell" id="auv-batt"></div>
-    <div class="graph-cell" id="auv-status"></div>
-    <div class="graph-cell wide" id="auv-motors"></div>
+  <!-- Tab: AUV -->
+  <div id="panel-auv" class="panel-section hidden">
+    <div class="panel-header" id="auv-panel-header">🛥 AUV</div>
+    <div class="graphs-grid" id="auv-graphs">
+      <div class="graph-cell" id="auv-pry"></div>
+      <div class="graph-cell" id="auv-depth"></div>
+      <div class="graph-cell" id="auv-alt"></div>
+      <div class="graph-cell" id="auv-obs"></div>
+      <div class="graph-cell" id="auv-usbl-dist"></div>
+      <div class="graph-cell" id="auv-usbl-angle"></div>
+      <div class="graph-cell" id="auv-batt"></div>
+      <div class="graph-cell" id="auv-status"></div>
+      <div class="graph-cell wide" id="auv-motors"></div>
+    </div>
   </div>
 </div>
 
@@ -383,8 +433,12 @@ flowchart LR
 <script src="https://cdn.plot.ly/plotly-2.35.2.min.js"></script>
 <script>
 // == Constants ==
-const API = 'http://192.168.0.83:8766';
-const API2 = 'http://192.168.0.83:8767';
+const API = (location.hostname === 'laboratoire.freeboxos.fr')
+  ? '/cosma-pK8j876lkj-api'
+  : 'http://192.168.0.83:8766';
+const API2 = (location.hostname === 'laboratoire.freeboxos.fr')
+  ? '/cosma-pK8j876lkj-pipe'
+  : 'http://192.168.0.83:8767';
 const COLORS = ['#00b4d8','#06d6a0','#ffd166','#e94560','#a855f7','#ff8800','#7dc8e0','#b8f0d4'];
 const AUV_COLOR = '#ff8800';
 const PLOTLY_LAYOUT = {
@@ -629,7 +683,10 @@ function initCursorSlider() {
   });
   cursorSlider.on('update', (values) => {
     tNow = Math.round(+values[0]);
-    document.getElementById('cursor-time').textContent = fmtMs(tNow);
+    // Show HH:MM:SS for slider label
+    const d = new Date(tNow);
+    const hms = d.toISOString().slice(11,19);
+    document.getElementById('cursor-time').textContent = `Heure: ${hms}`;
     applyTrailAndCursor();
   });
   document.getElementById('trail-select').addEventListener('change', () => applyTrailAndCursor());
@@ -670,7 +727,8 @@ function clearMapLayers() {
 
 // == Load data for a given date ==
 async function loadDate(date) {
-  setStatus('Chargement...');
+  setStatus('chargement...');
+  showNoDataOverlay(true);
   clearMapLayers();
   allPoints = [];
   usblPoints = [];
@@ -760,6 +818,7 @@ async function loadDate(date) {
     populatePlotlyCharts();
     initCursorSlider();
     applyTrailAndCursor();
+    showNoDataOverlay(false);
 
     document.getElementById('title').textContent = `COSMA v6 — ${date}`;
     setStatus(`${totalShip} USV sess. | ${totalSub} AUV sess. | ${allPoints.length} pts USV | ${usblPoints.length} pts USBL`);
@@ -940,6 +999,28 @@ function datePickerToday() {
   loadDate(today);
 }
 
+// == Tab switching ==
+function switchTab(name) {
+  ['charts','usv','auv'].forEach(t => {
+    const p = document.getElementById('panel-'+t);
+    if (p) p.classList.toggle('active', t === name);
+    if (p) p.classList.toggle('hidden', t !== name);
+  });
+  document.querySelectorAll('.panel-tab').forEach((btn, i) => {
+    const names = ['charts','usv','auv'];
+    btn.classList.toggle('active', names[i] === name);
+  });
+}
+
+// == No-data overlay ==
+function showNoDataOverlay(show) {
+  const el = document.getElementById('no-data-overlay');
+  if (el) el.classList.toggle('hidden', !show);
+  // Show/hide layer toggles
+  const lt = document.getElementById('map-layer-toggles');
+  if (lt) lt.style.display = show ? 'none' : 'flex';
+}
+
 // == Pipeline overlay ==
 let _pipelineRendered = false;
 function togglePipeline() {
@@ -1138,6 +1219,7 @@ function _wireSortieSelect() {
   sel.addEventListener('change', () => {
     const btn = document.getElementById('btn-sync');
     btn.disabled = !sel.value;
+    _updateMissionLabelHeader(sel.value);
     if (sel.value) {
       const opt = sel.options[sel.selectedIndex];
       if (opt.textContent.includes('✓')) {
@@ -1155,7 +1237,7 @@ function _populateSortieSelect(sorties) {
     sel.options[0].textContent = '— Aucune sortie —';
     return;
   }
-  sel.options[0].textContent = '— Sortie —';
+  sel.options[0].textContent = `${sorties.length} sorties dispo — sélectionnez`;
   sorties.forEach(s => {
     const opt = document.createElement('option');
     opt.value = s.id;
@@ -1165,6 +1247,13 @@ function _populateSortieSelect(sorties) {
   _wireSortieSelect();
 }
 
+function _updateMissionLabelHeader(sortieId) {
+  const el = document.getElementById('mission-label-header');
+  if (!el) return;
+  el.textContent = sortieId ? `Mission: ${sortieId}` : '';
+  el.style.color = sortieId ? '#06d6a0' : '#555';
+}
+
 function loadSorties() {
   const sel = document.getElementById('sortie-select');
   sel.options[0].textContent = 'Sorties: chargement…';