diff --git a/llm_team_ui.py b/llm_team_ui.py
index 117bf93..82f7f20 100644
--- a/llm_team_ui.py
+++ b/llm_team_ui.py
@@ -775,13 +775,21 @@ async function loadThreats() {
 
     sentinelCard.appendChild(sHeader);
 
-    // Start countdown
+    // Countdown synced to server's next_scan_ts
+    // Store the absolute target time so refresh doesn't reset
     if (window._sentinelTimer) clearInterval(window._sentinelTimer);
-    window._sentinelCountdown = nextIn;
+    var serverNow = sentinel.server_time || (Date.now()/1000);
+    var nextScanTs = serverNow + nextIn;
+    window._sentinelTargetTs = nextScanTs;
+    window._sentinelServerOffset = serverNow - (Date.now()/1000); // clock difference
     window._sentinelTimer = setInterval(function(){
-      window._sentinelCountdown = Math.max(0, window._sentinelCountdown - 1);
+      var localNow = (Date.now()/1000) + (window._sentinelServerOffset||0);
+      var remaining = Math.max(0, (window._sentinelTargetTs||0) - localNow);
       var el = document.getElementById('sentinel-countdown');
-      if (el) { el.textContent = Math.ceil(window._sentinelCountdown) || '...'; if (window._sentinelCountdown <= 0) { el.textContent = '✓'; el.style.color = '#4ade80'; clearInterval(window._sentinelTimer); } }
+      if (el) {
+        if (remaining > 0) { el.textContent = Math.ceil(remaining); el.style.color = '#d946ef'; }
+        else { el.textContent = '✓'; el.style.color = '#4ade80'; }
+      }
     }, 1000);
 
     if (ss.last_error) {
@@ -6390,7 +6398,7 @@ SENTINEL_MODEL = "qwen2.5:latest"
 SENTINEL_INTERVAL = 300  # 5 minutes
 _sentinel_last_pos = 0
 _sentinel_results = []  # last 50 analyses
-_sentinel_stats = {"scans": 0, "bans": 0, "last_run": None, "last_error": None}
+_sentinel_stats = {"scans": 0, "bans": 0, "last_run": None, "last_error": None, "next_scan_ts": 0}
 
 def _sentinel_log_entry(msg):
     """Write to sentinel log file."""
@@ -6573,6 +6581,7 @@ def _sentinel_loop():
 
     _sentinel_log_entry("SENTINEL_START model=" + SENTINEL_MODEL + " interval=" + str(SENTINEL_INTERVAL) + "s")
     while True:
+        _sentinel_stats["next_scan_ts"] = time.time() + SENTINEL_INTERVAL
         time.sleep(SENTINEL_INTERVAL)
         try:
             _sentinel_scan()
@@ -6585,18 +6594,16 @@ def _sentinel_loop():
 @app.route("/api/admin/sentinel")
 @admin_required
 def admin_sentinel_status():
-    last_ts = _sentinel_stats.get("last_run_ts", 0)
     now = time.time()
-    elapsed = now - last_ts if last_ts else 0
-    next_in = max(0, SENTINEL_INTERVAL - elapsed)
+    next_ts = _sentinel_stats.get("next_scan_ts", 0)
+    next_in = max(0, next_ts - now)
     return jsonify({
         "stats": _sentinel_stats,
         "recent_verdicts": list(reversed(_sentinel_results[-20:])),
         "model": SENTINEL_MODEL,
         "interval": SENTINEL_INTERVAL,
-        "elapsed_since_scan": round(elapsed, 1),
         "next_scan_in": round(next_in, 1),
-        "server_time": now
+        "server_time": round(now, 1)
     })