diff --git a/app/static/js/fillword.js b/app/static/js/fillword.js
index b967633..f33a3bd 100644
--- a/app/static/js/fillword.js
+++ b/app/static/js/fillword.js
@@ -1,5 +1,6 @@
 let isRead = true;
 let isChoose = true;
+let highlightWords = "";
 
 function getWord() {
     return window.getSelection ? window.getSelection() : document.selection.createRange().text;
@@ -8,7 +9,13 @@ function getWord() {
 function fillInWord() {
     let word = getWord();
     if (isRead) Reader.read(word, inputSlider.value);
-    if (!isChoose) return;
+    if (!isChoose) {
+        if(isHighlight){
+             const element = document.getElementById("selected-words3");
+             element.value = element.value + " " + word;
+        }
+        return;
+    }
     const element = document.getElementById("selected-words");
     element.value = element.value + " " + word;
 }
@@ -29,3 +36,8 @@ function onReadClick() {
 function onChooseClick() {
     isChoose = !isChoose;
 }
+
+// 如果网页刷新，停止播放声音
+if (performance.getEntriesByType("navigation")[0].type == "reload") {
+    Reader.stopRead();
+}
\ No newline at end of file
diff --git a/app/static/js/highlight.js b/app/static/js/highlight.js
index 0cea31a..f0680af 100644
--- a/app/static/js/highlight.js
+++ b/app/static/js/highlight.js
@@ -22,62 +22,40 @@ function getWord() {
 
 function highLight() {
     if (!isHighlight) return;
-    let articleContent = document.getElementById("article").innerText; //将原来的.innerText改为.innerHtml，使用innerText会把原文章中所包含的<br>标签去除，导致处理后的文章内容失去了原来的格式
+    let articleContent = document.getElementById("article").innerHTML; // innerHTML保留HTML标签来保持部分格式，且适配不同的浏览器
     let pickedWords = document.getElementById("selected-words");  // words picked to the text area
     let dictionaryWords = document.getElementById("selected-words2"); // words appearing in the user's new words list
-    let allWords = "";  //初始化allWords的值，避免进入判断后编译器认为allWords未初始化的问题
-    if(dictionaryWords != null){//增加一个判断，检查生词本里面是否为空，如果为空，allWords只添加选中的单词
-        allWords = pickedWords.value + " " + dictionaryWords.value;
-    }
-    else{
-        allWords = pickedWords.value + " ";
-    }
-    const list = allWords.split(" ");//将所有的生词放入一个list中，用于后续处理
+    let allWords = dictionaryWords == null ? pickedWords.value + " " : pickedWords.value + " " + dictionaryWords.value;
+    highlightWords = document.getElementById("selected-words3");
+    allWords = highlightWords == null ? allWords : allWords + " " + highlightWords.value;
+    const list = allWords.split(" "); // 将所有的生词放入一个list中
+    let totalSet = new Set();
     for (let i = 0; i < list.length; ++i) {
-        list[i] = list[i].replace(/(^\s*)|(\s*$)/g, ""); //消除单词两边的空字符
-        list[i] = list[i].replace('|', "");
-        list[i] = list[i].replace('?', "");
-        if (list[i] !== "" && "<mark>".indexOf(list[i]) === -1 && "</mark>".indexOf(list[i]) === -1) {
-           //将文章中所有出现该单词word的地方改为："<mark>" + word + "<mark>"。 正则表达式RegExp()中，"\\b"代表单词边界匹配。
-
-            //修改代码
-            let articleContent_fb = articleContent;  //文章副本
-            while(articleContent_fb.toLowerCase().indexOf(list[i].toLowerCase()) !== -1 && list[i]!=""){
-                //找到副本中和list[i]匹配的第一个单词(第一种匹配情况),并赋值给list[i]。
-                const index = articleContent_fb.toLowerCase().indexOf(list[i].toLowerCase());
-                list[i] = articleContent_fb.substring(index, index + list[i].length);
-
-                articleContent_fb = articleContent_fb.substring(index + list[i].length);    // 使用副本中list[i]之后的子串替换掉副本
-                articleContent = articleContent.replace(new RegExp("\\b"+list[i]+"\\b","g"),"<mark>" + list[i] + "</mark>");
+        list[i] = list[i].replace(/(^\W*)|(\W*$)/g, ""); // 消除单词两边的非单词字符
+        if (list[i] != "" && !totalSet.has(list[i])) {
+            // 返回所有匹配单词的集合, 正则表达式RegExp()中, "\b"匹配一个单词的边界, g 表示全局匹配, i 表示对大小写不敏感。
+            let matches = new Set(articleContent.match(new RegExp("\\b" + list[i] + "\\b", "gi")));
+            if (matches.has("mark")) {
+                // 优先处理单词为 "mark" 的情况
+                totalSet = new Set(["mark", ...totalSet]);
             }
+            totalSet = new Set([...totalSet, ...matches]);
         }
+    } 
+    // 删除所有的mark标签,防止标签发生嵌套
+    articleContent = articleContent.replace(/<(mark)[^>]*>/gi, "");
+    articleContent = articleContent.replace(/<(\/mark)[^>]*>/gi, "");
+    // 将文章中所有出现该单词word的地方改为："<mark>" + word + "<mark>"。
+    for (let word of totalSet) {
+        articleContent = articleContent.replace(new RegExp("\\b" + word + "\\b", "g"), "<mark>" + word + "</mark>");
     }
     document.getElementById("article").innerHTML = articleContent;
 }
 
 function cancelHighlighting() {
-    let articleContent = document.getElementById("article").innerText;//将原来的.innerText改为.innerHtml，原因同上
-    let pickedWords = document.getElementById("selected-words");
-    const dictionaryWords = document.getElementById("selected-words2");    
-    const list = pickedWords.value.split(" ");    
-    if (pickedWords != null) {
-        for (let i = 0; i < list.length; ++i) {
-            list[i] = list[i].replace(/(^\s*)|(\s*$)/g, "");
-            if (list[i] !== "") { //原来判断的代码中，替换的内容为“list[i]”这个字符串，这明显是错误的，我们需要替换的是list[i]里的内容
-                articleContent = articleContent.replace(new RegExp("<mark>"+list[i]+"</mark>", "g"), list[i]);
-            }
-        }
-    }
-    if (dictionaryWords != null) {
-        let list2 = pickedWords.value.split(" ");
-        for (let i = 0; i < list2.length; ++i) {
-            list2 = dictionaryWords.value.split(" ");
-            list2[i] = list2[i].replace(/(^\s*)|(\s*$)/g, "");
-            if (list2[i] !== "") { //原来代码中，替换的内容为“list[i]”这个字符串，这明显是错误的，我们需要替换的是list[i]里的内容
-                articleContent = articleContent.replace(new RegExp("<mark>"+list2[i]+"</mark>", "g"), list2[i]);
-            }
-        }
-    }
+    let articleContent = document.getElementById("article").innerHTML;
+    articleContent = articleContent.replace(/<(mark)[^>]*>/gi, "");
+    articleContent = articleContent.replace(/<(\/mark)[^>]*>/gi, "");
     document.getElementById("article").innerHTML = articleContent;
 }
 
@@ -99,4 +77,4 @@ function toggleHighlighting() {
     }
 }
 
-showBtnHandler();
+showBtnHandler();
\ No newline at end of file
diff --git a/app/templates/userpage_get.html b/app/templates/userpage_get.html
index 68997ef..79031be 100644
--- a/app/templates/userpage_get.html
+++ b/app/templates/userpage_get.html
@@ -5,6 +5,8 @@
     <meta name="viewport"
           content="width=device-width, initial-scale=1.0, minimum-scale=0.5, maximum-scale=3.0, user-scalable=yes"/>
     <meta name="format-detection" content="telephone=no"/>
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.1/dist/css/bootstrap.min.css" rel="stylesheet">
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.1/dist/js/bootstrap.bundle.min.js"></script>
 
     {{ yml['header'] | safe }}
     {% if yml['css']['item'] %}
@@ -21,17 +23,35 @@
     <title>EnglishPal Study Room for {{ username }}</title>
 
     <style>
-        .shaking {
-            animation: shakes 1600ms ease-in-out;
-        }
+      .shaking {
+          animation: shakes 1600ms ease-in-out;
+      }
+
+      @keyframes shakes {
+          10%, 90% { transform: translate3d(-1px, 0, 0); }
+          20%, 50% { transform: translate3d(+2px, 0, 0); }
+          30%, 70% { transform: translate3d(-4px, 0, 0); }
+          40%, 60% { transform: translate3d(+4px, 0, 0); }
+          50% { transform: translate3d(-4px, 0, 0); }
+      }
+
+      .lead{
+          font-size: 22px;
+          font-family: Helvetica, sans-serif;
+          white-space: pre-wrap;
+      }
+
+      .arrow {
+	  padding: 0;
+	  font-size: 20px;
+	  line-height: 21px;
+	  display: inline-block;
+      }
+
+      .arrow:hover {
+	  cursor: pointer;
+      }
 
-        @keyframes shakes {
-            10%, 90% { transform: translate3d(-1px, 0, 0); }
-            20%, 50% { transform: translate3d(+2px, 0, 0); }
-            30%, 70% { transform: translate3d(-4px, 0, 0); }
-            40%, 60% { transform: translate3d(+4px, 0, 0); }
-            50% { transform: translate3d(-4px, 0, 0); }
-        }
     </style>
 </head>
 <body>
@@ -45,22 +65,28 @@
         <a class="btn btn-secondary" href="/reset" role="button" onclick="stopRead()">重设密码</a>
 
     </p>
-{#    {% for message in flashed_messages %}#} {# 根据user_service.userpage,取消了参数flashed_messages，因此注释了这段代码 #}
-{#        <div class="alert alert-warning" role="alert">Congratulations! {{ message }}</div>#}
-{#    {% endfor %}#}
+    {% for message in get_flashed_messages() %}
+    <div class="alert alert-warning alert-dismissible fade show" role="alert">
+	{{ message }}
+	<button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
+    </div>
+    {% endfor %}
 
-        <button class="btn btn-success" id="load_next_article" onclick="load_next_article()"> 下一篇 Next Article </button>
-        <button class="btn btn-success" id="load_pre_article" onclick="load_pre_article()" > 上一篇 Previous Article </button>
+        <button class="arrow" id="load_next_article" onclick="load_next_article();Reader.stopRead()" title="下一篇 Next Article">⇨</button>
+        <button class="arrow" id="load_pre_article" onclick="load_pre_article();Reader.stopRead()" style="display: none" title="上一篇 Previous Article">⇦</button>
 
     <p><b>阅读文章并回答问题</b></p>
     <div id="text-content">
         <div id="found">
-            <div class="alert alert-success" role="alert">According to your word list, your level is <span class="badge bg-success" id="user-level">{{ today_article["user_level"] }}</span>  and we have chosen an article with a difficulty level of <span class="badge bg-success" id="text_level">{{ today_article["text_level"] }}</span> for you.</div>
+            <div class="alert alert-success" role="alert">According to your word list, your level is <span class="text-decoration-underline" id="user_level">{{ today_article["user_level"] }}</span>  and we have chosen an article with a difficulty level of <span class="text-decoration-underline" id="text_level">{{ today_article["text_level"] }}</span> for you.</div>
                 <p class="text-muted" id="date">Article added on: {{ today_article["date"] }}</p><br/>
-            <div class="p-3 mb-2 bg-light text-dark"><br/>
-            <p class="display-5" id="article_title">{{ today_article["article_title"] }}</p><br/>
-            <p class="lead"><font id="article" size=2>{{ today_article["article_body"] }}</font></p><br/>
-            <p><small class="text-muted" id="source">{{ today_article['source'] }}</small></p><br/>
+            <div class="p-3 mb-2 bg-light text-dark" style="margin: 0 0.5%;"><br/>
+            <p class="display-6" id="article_title">{{ today_article["article_title"] }}</p><br/>
+            <p class="lead"><font id="article">{{ today_article["article_body"] }}</font></p><br/>
+            <div>
+                <p><small class="text-muted" id="source">{{ today_article['source'] }}</small></p><br/>
+            </div>
+            
             <p><b id="question">{{ today_article['question'] }}</b></p><br/>
                 <script type="text/javascript">
                     function toggle_visibility(id) { {# https://css-tricks.com/snippets/javascript/showhide-element/#}
@@ -85,7 +111,7 @@
 
     <input type="checkbox" onclick="toggleHighlighting()" checked/>生词高亮
     <input type="checkbox" onclick="onReadClick()" checked/>大声朗读
-    <input type="checkbox" onclick="onChooseClick()" checked/>划词入库
+    <input type="checkbox" onclick="onChooseClick()" checked id="test1"/>划词入库
     <div class="range">
         <div class="field">
             <div class="sliderValue">
@@ -97,8 +123,8 @@
     <p><b>收集生词吧</b> （可以在正文中划词，也可以复制黏贴）</p>
     <form method="post" action="/{{ username }}/userpage">
         <textarea name="content" id="selected-words" rows="10" cols="120"></textarea><br/>
-        <input type="submit" value="把生词加入我的生词库"/>
-        <input type="reset" value="清除"/>
+        <button class="btn btn-primary btn-lg" type="submit" onclick="Reader.stopRead()">把生词加入我的生词库</button>
+        <button class="btn btn-primary btn-lg" type="reset">清除</button>
     </form>
     {% if session.get['thisWord'] %}
         <script type="text/javascript">
@@ -140,6 +166,7 @@
         <input id="selected-words2" type="hidden" value="{{ words }}">
     {% endif %}
 </div>
+<label id="selected-words3" type="hidden">
 {{ yml['footer'] | safe }}
 {% if yml['js']['bottom'] %}
     {% for js in yml['js']['bottom'] %}
@@ -147,6 +174,12 @@
     {% endfor %}
 {% endif %}
 <script type="text/javascript">
+    window.onload = function () { // 页面加载时执行
+        // 刷新页面或进入页面时判断，若不是首篇文章，则上一篇按钮可见
+        if(sessionStorage.getItem('pre_page_button')!="display" && sessionStorage.getItem('pre_page_button')){
+            $('#load_pre_article').show();
+        }
+     };
     function load_next_article(){
         $.ajax({
             url: '/get_next_article/{{username}}',
@@ -175,7 +208,7 @@
         });
     }
     function update(today_article){
-        $('#user-level').html(today_article['user_level']);
+        $('#user_level').html(today_article['user_level']);
         $('#text_level').html(today_article["text_level"]);
         $('#date').html('Article added on: '+today_article["date"]);
         $('#article_title').html(today_article["article_title"]);
@@ -183,13 +216,19 @@
         $('#source').html(today_article['source']);
         $('#question').html(today_article["question"]);
         $('#answer').html(today_article["answer"]);
+        document.querySelector('#text_level').classList.add('mark'); // highlight text difficult level for 2 seconds
+        setTimeout(() => {document.querySelector('#text_level').classList.remove('mark');}, 2000);
+        document.querySelector('#user_level').classList.add('mark'); // do the same thing for user difficulty level
+        setTimeout(() => {document.querySelector('#user_level').classList.remove('mark');}, 2000);
     }
 <!-- 检查是否存在上一篇或下一篇，不存在则对应按钮隐藏-->
     function check_pre(visited_articles){
         if((visited_articles=='')||(visited_articles['index']<=0)){
             $('#load_pre_article').hide();
+            sessionStorage.setItem('pre_page_button', 'display')
         }else{
             $('#load_pre_article').show();
+            sessionStorage.setItem('pre_page_button', 'show')
         }
     }
     function check_next(result_of_generate_article){
@@ -210,7 +249,7 @@
 </body>
 <style>
     mark {
-        color: #{{ yml['highlight']['color'] }};
+        color:#{{ yml['highlight']['color'] }};
         background-color: rgba(0, 0, 0, 0);
     }
 </style>
diff --git a/app/test/test_bug546_lixiaofeng.py b/app/test/test_bug546_lixiaofeng.py
new file mode 100644
index 0000000..649aeba
--- /dev/null
+++ b/app/test/test_bug546_lixiaofeng.py
@@ -0,0 +1,39 @@
+from selenium.webdriver.common.action_chains import ActionChains
+from helper import signup
+
+
+def test_highlight(driver, URL):
+    try:
+        # 打开网页
+        driver.get(URL)
+        driver.maximize_window()
+
+        # 注册
+        signup(URL, driver)
+
+        # 取消勾选“划词入库按钮”
+        highlight_checkbox = driver.find_element_by_id("test1")
+        driver.execute_script("arguments[0].click();", highlight_checkbox)
+
+        article = driver.find_element_by_id("article")
+
+        # 创建 ActionChains 对象
+        actions = ActionChains(driver)
+
+        # 移动鼠标到起点位置
+        actions.move_to_element(article)
+        # actions.move_to_element_with_offset(article, 50, 100)
+        # 按下鼠标左键
+        actions.click_and_hold()
+        # 拖动鼠标到结束位置
+        actions.move_by_offset(400,50)
+        # 释放鼠标左键
+        actions.release()
+        # 执行操作链
+        actions.perform()
+        # time.sleep(10)
+
+        assert driver.find_element_by_tag_name("mark") is not None
+    finally:
+        # 测试结束后关闭浏览器
+        driver.quit()
\ No newline at end of file