diff --git a/public/js/app.js b/public/js/app.js
index 1623908..051bd43 100644
--- a/public/js/app.js
+++ b/public/js/app.js
@@ -111,6 +111,8 @@
   // ---- State ----
   let previousMetrics = null;
   let networkChart = null;
+  let ws = null; // WebSocket instance
+  let isWsConnecting = false; // Connection lock
   let user = null; // Currently logged in user
   let currentServerDetail = { instance: null, job: null, source: null, charts: {} };
   let allServersData = [];
@@ -119,6 +121,10 @@
   let pageSize = 20;
   let currentLatencies = []; // Array of {id, source, dest, latency}
   let latencyTimer = null;
+  let mapResizeHandler = null; // For map cleanup
+  let siteThemeQuery = null; // For media query cleanup
+  let siteThemeHandler = null;
+  let backgroundIntervals = []; // To track setIntervals
   
   // Load sort state from localStorage or use default
   let currentSort = { column: 'up', direction: 'desc' };
@@ -357,28 +363,42 @@
 
       // Still populate inputs
       dom.pageNameInput.value = window.SITE_SETTINGS.page_name || '';
-      dom.siteTitleInput.value = window.SITE_SETTINGS.title || '';
-      dom.logoUrlInput.value = window.SITE_SETTINGS.logo_url || '';
-      dom.defaultThemeInput.value = window.SITE_SETTINGS.default_theme || 'dark';
-      dom.show95BandwidthInput.value = window.SITE_SETTINGS.show_95_bandwidth ? "1" : "0";
-      dom.p95TypeSelect.value = window.SITE_SETTINGS.p95_type || 'tx';
+      if (dom.siteTitleInput) dom.siteTitleInput.value = window.SITE_SETTINGS.title || '';
+      if (dom.logoUrlInput) dom.logoUrlInput.value = window.SITE_SETTINGS.logo_url || '';
+      if (dom.defaultThemeInput) dom.defaultThemeInput.value = window.SITE_SETTINGS.default_theme || 'dark';
+      if (dom.show95BandwidthInput) dom.show95BandwidthInput.value = window.SITE_SETTINGS.show_95_bandwidth ? "1" : "0";
+      if (dom.p95TypeSelect) dom.p95TypeSelect.value = window.SITE_SETTINGS.p95_type || 'tx';
       // Latency routes loaded separately in openSettings or on startup
     }
 
     loadSiteSettings();
 
-    // setInterval(fetchMetrics, REFRESH_INTERVAL); - Now using WebSockets
+    // Track intervals for resource management
     initWebSocket();
-    setInterval(fetchNetworkHistory, NETWORK_HISTORY_INTERVAL);
-    fetchLatency();
-    setInterval(fetchLatency, REFRESH_INTERVAL);
+    backgroundIntervals.push(setInterval(fetchNetworkHistory, NETWORK_HISTORY_INTERVAL));
+    backgroundIntervals.push(setInterval(fetchLatency, REFRESH_INTERVAL));
   }
 
   // ---- Real-time WebSocket ----
   function initWebSocket() {
+    if (isWsConnecting) return;
+    isWsConnecting = true;
+
+    if (ws) {
+      ws.onmessage = null;
+      ws.onclose = null;
+      ws.onerror = null;
+      ws.close();
+    }
+
     const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
     const wsUrl = `${protocol}//${window.location.host}`;
-    const ws = new WebSocket(wsUrl);
+    ws = new WebSocket(wsUrl);
+
+    ws.onopen = () => {
+      isWsConnecting = false;
+      console.log('WS connection established');
+    };
 
     ws.onmessage = (event) => {
       try {
@@ -394,12 +414,13 @@
     };
 
     ws.onclose = () => {
+      isWsConnecting = false;
       console.log('WS connection closed. Reconnecting in 5s...');
       setTimeout(initWebSocket, 5000);
     };
 
     ws.onerror = (err) => {
-      // Small silent error here to not alert the user constantly if server is down during maintenance
+      isWsConnecting = false;
       ws.close();
     };
   }
@@ -597,6 +618,13 @@
         
         echarts.registerMap('world', worldJSON);
 
+        if (myMap2D) {
+            myMap2D.dispose();
+            if (mapResizeHandler) {
+                window.removeEventListener('resize', mapResizeHandler);
+            }
+        }
+
         myMap2D = echarts.init(dom.globeContainer);
         
         const isLight = document.documentElement.classList.contains('light-theme');
@@ -663,7 +691,10 @@
 
         myMap2D.setOption(option);
 
-        window.addEventListener('resize', () => myMap2D.resize());
+        mapResizeHandler = debounce(() => {
+            if (myMap2D) myMap2D.resize();
+        }, 100);
+        window.addEventListener('resize', mapResizeHandler);
         
         if (allServersData.length > 0) {
             updateMap2D(allServersData);
@@ -1155,6 +1186,13 @@
 
   // ---- Server Detail ----
   async function openServerDetail(instance, job, source) {
+    // Cleanup old charts if any were still present from a previous open (safety)
+    if (currentServerDetail.charts) {
+        Object.values(currentServerDetail.charts).forEach(chart => {
+            if (chart && chart.destroy) chart.destroy();
+        });
+    }
+    
     currentServerDetail = { instance, job, source, charts: {} };
     dom.serverDetailTitle.textContent = `${job}`;
     dom.serverDetailModal.classList.add('active');
@@ -1505,15 +1543,21 @@
       const themeToApply = savedTheme || settings.default_theme || 'dark';
       applyTheme(themeToApply);
 
-      // Listen for system theme changes if set to auto
-      window.matchMedia('(prefers-color-scheme: light)').addEventListener('change', () => {
+      // Listen for system theme changes if set to auto (cleanup existing listener first)
+      if (siteThemeQuery && siteThemeHandler) {
+          siteThemeQuery.removeEventListener('change', siteThemeHandler);
+      }
+      
+      siteThemeQuery = window.matchMedia('(prefers-color-scheme: light)');
+      siteThemeHandler = () => {
         const currentSavedTheme = localStorage.getItem('theme');
         const defaultTheme = window.SITE_SETTINGS ? window.SITE_SETTINGS.default_theme : 'dark';
         const activeTheme = currentSavedTheme || defaultTheme;
         if (activeTheme === 'auto') {
           applyTheme('auto');
         }
-      });
+      };
+      siteThemeQuery.addEventListener('change', siteThemeHandler);
     } catch (err) {
       console.error('Error loading site settings:', err);
     }
diff --git a/public/js/chart.js b/public/js/chart.js
index e525f2e..2d8f5af 100644
--- a/public/js/chart.js
+++ b/public/js/chart.js
@@ -16,10 +16,11 @@ class AreaChart {
     this.dpr = window.devicePixelRatio || 1;
     this.padding = { top: 20, right: 16, bottom: 32, left: 56 };
 
-    this.currentMaxVal = 0;
     this.prevMaxVal = 0;
+    this.currentMaxVal = 0;
 
-    this._resize = this.resize.bind(this);
+    // Use debounced resize for performance and safety
+    this._resize = typeof debounce === 'function' ? debounce(this.resize.bind(this), 100) : this.resize.bind(this);
     window.addEventListener('resize', this._resize);
     this.resize();
   }
@@ -335,7 +336,8 @@ class MetricChart {
     this.prevMaxVal = 0;
     this.currentMaxVal = 0;
 
-    this._resize = this.resize.bind(this);
+    // Use debounced resize for performance and safety
+    this._resize = typeof debounce === 'function' ? debounce(this.resize.bind(this), 100) : this.resize.bind(this);
     window.addEventListener('resize', this._resize);
     this.resize();
   }
diff --git a/public/js/utils.js b/public/js/utils.js
index 42e48f0..fd7200d 100644
--- a/public/js/utils.js
+++ b/public/js/utils.js
@@ -111,3 +111,17 @@ function animateValue(element, start, end, duration = 600) {
 
   requestAnimationFrame(update);
 }
+
+/**
+ * Debounce function to limit execution frequency
+ */
+function debounce(fn, delay) {
+  let timer = null;
+  return function (...args) {
+    if (timer) clearTimeout(timer);
+    timer = setTimeout(() => {
+      fn.apply(this, args);
+      timer = null;
+    }, delay);
+  };
+}