diff --git a/content.js b/content.js
index 9760e16..6f48de7 100644
--- a/content.js
+++ b/content.js
@@ -3,51 +3,77 @@ function escapeRegex(s) {
 }
 
 function highlightWords(lists) {
-  const textNodes = [];
-  const walker = document.createTreeWalker(document.body, NodeFilter.SHOW_TEXT, {
-    acceptNode: node => {
-      if (node.parentNode && ['SCRIPT', 'STYLE', 'NOSCRIPT', 'IFRAME'].includes(node.parentNode.nodeName)) return NodeFilter.FILTER_REJECT;
-      if (!node.nodeValue.trim()) return NodeFilter.FILTER_SKIP;
-      return NodeFilter.FILTER_ACCEPT;
-    }
-  });
-
-  while (walker.nextNode()) textNodes.push(walker.currentNode);
-
-  const activeWords = [];
-
-  for (const list of lists) {
-    if (!list.active) continue;
-    for (const word of list.words) {
-      if (!word.active) continue;
-      activeWords.push({
-        text: word.wordStr,
-        background: word.background || list.background,
-        foreground: word.foreground || list.foreground
-      });
-    }
-  }
-
-  if (activeWords.length === 0) return;
-
-  const wordMap = new Map();
-  for (const word of activeWords) wordMap.set(word.text.toLowerCase(), word);
-
-  const pattern = new RegExp(`(${Array.from(wordMap.keys()).map(escapeRegex).join('|')})`, 'gi');
-
-  for (const node of textNodes) {
-    if (!pattern.test(node.nodeValue)) continue;
-
-    const span = document.createElement('span');
-    span.innerHTML = node.nodeValue.replace(pattern, match => {
-      const word = wordMap.get(match.toLowerCase()) || { background: '#ffff00', foreground: '#000000' };
-      return `<mark style="background:${word.background};color:${word.foreground};padding:0 2px;">${match}</mark>`;
+  const processNodes = () => {
+    const textNodes = [];
+    const walker = document.createTreeWalker(document.body, NodeFilter.SHOW_TEXT, {
+      acceptNode: node => {
+        if (node.parentNode && node.parentNode.nodeName === 'MARK') return NodeFilter.FILTER_REJECT;
+        if (node.parentNode && ['SCRIPT', 'STYLE', 'NOSCRIPT', 'IFRAME'].includes(node.parentNode.nodeName)) return NodeFilter.FILTER_REJECT;
+        if (!node.nodeValue.trim()) return NodeFilter.FILTER_SKIP;
+        return NodeFilter.FILTER_ACCEPT;
+      }
     });
 
-    node.parentNode.replaceChild(span, node);
-  }
+    while (walker.nextNode()) textNodes.push(walker.currentNode);
+
+    const activeWords = [];
+
+    for (const list of lists) {
+      if (!list.active) continue;
+      for (const word of list.words) {
+        if (!word.active) continue;
+        activeWords.push({
+          text: word.wordStr,
+          background: word.background || list.background,
+          foreground: word.foreground || list.foreground
+        });
+      }
+    }
+
+    if (activeWords.length === 0) return;
+
+    const wordMap = new Map();
+    for (const word of activeWords) wordMap.set(word.text.toLowerCase(), word);
+
+    const pattern = new RegExp(`(${Array.from(wordMap.keys()).map(escapeRegex).join('|')})`, 'gi');
+
+    for (const node of textNodes) {
+      if (!pattern.test(node.nodeValue)) continue;
+
+      const span = document.createElement('span');
+      span.innerHTML = node.nodeValue.replace(pattern, match => {
+        const word = wordMap.get(match.toLowerCase()) || { background: '#ffff00', foreground: '#000000' };
+        return `<mark style="background:${word.background};color:${word.foreground};padding:0 2px;">${match}</mark>`;
+      });
+
+      node.parentNode.replaceChild(span, node);
+    }
+  };
+
+  const debouncedProcessNodes = debounce(processNodes, 300);
+
+  debouncedProcessNodes();
+
+  const observer = new MutationObserver(debouncedProcessNodes);
+  observer.observe(document.body, {
+    childList: true,
+    subtree: true,
+    characterData: true
+  });
+
+  window.addEventListener('scroll', debouncedProcessNodes);
+}
+
+// Debounce helper function
+function debounce(func, wait) {
+  let timeout;
+  return function () {
+    const context = this, args = arguments;
+    clearTimeout(timeout);
+    timeout = setTimeout(() => func.apply(context, args), wait);
+  };
 }
 
 chrome.storage.local.get("lists", ({ lists }) => {
   if (Array.isArray(lists)) highlightWords(lists);
-});
+});
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