diff --git a/src/components/RichTextEditor.vue b/src/components/RichTextEditor.vue
index 2e75817..7a667a6 100644
--- a/src/components/RichTextEditor.vue
+++ b/src/components/RichTextEditor.vue
@@ -67,8 +67,60 @@ const tools = ref([
   },
 ])
 
+// 检查当前选区是否已经在某种格式中
+const isAlreadyInFormat = formatType => {
+  const selection = window.getSelection()
+  if (selection.rangeCount > 0) {
+    const range = selection.getRangeAt(0)
+    const container = range.commonAncestorContainer
+
+    // 向上查找父元素，检查是否已经在指定格式中
+    let current = container.nodeType === Node.TEXT_NODE ? container.parentElement : container
+    while (current && current !== editorRef.value) {
+      if (formatType === 'bold' && current.tagName === 'B') return true
+      if (formatType === 'center' && current.style.textAlign === 'center') return true
+      if (formatType === 'header' && current.tagName === 'H2') return true
+      if (formatType === 'quote' && (current.tagName === 'BLOCKQUOTE' || current.classList.contains('quote-content'))) return true
+      if (formatType === 'list' && (current.tagName === 'UL' || current.tagName === 'OL' || current.tagName === 'LI')) return true
+      current = current.parentElement
+    }
+  }
+  return false
+}
+
+// 检查是否在列表、引用或待办事项中（用于嵌套限制）
+const isInListOrQuote = () => {
+  const selection = window.getSelection()
+  if (selection.rangeCount > 0) {
+    const range = selection.getRangeAt(0)
+    const container = range.commonAncestorContainer
+
+    // 向上查找父元素，检查是否在列表、引用或待办事项中
+    let current = container.nodeType === Node.TEXT_NODE ? container.parentElement : container
+    while (current && current !== editorRef.value) {
+      if (current.tagName === 'UL' || current.tagName === 'OL' || current.tagName === 'LI' || current.tagName === 'BLOCKQUOTE' || current.classList.contains('quote-content') || current.classList.contains('todo-container')) {
+        return true
+      }
+      current = current.parentElement
+    }
+  }
+  return false
+}
+
 // 格式化文本
 const formatText = (command, value = null) => {
+  // 检查是否已经应用了相同的格式
+  if (command === 'bold' && isAlreadyInFormat('bold')) return
+  if (command === 'justifyCenter' && isAlreadyInFormat('center')) return
+  if (command === 'formatBlock' && value === 'h2' && isAlreadyInFormat('header')) return
+  if (command === 'formatBlock' && value === 'blockquote' && isAlreadyInFormat('quote')) return
+  if (command === 'insertUnorderedList' && isAlreadyInFormat('list')) return
+
+  // 检查嵌套限制
+  if ((command === 'insertUnorderedList' || (command === 'formatBlock' && value === 'blockquote')) && isInListOrQuote()) {
+    return
+  }
+
   document.execCommand(command, false, value)
   updateToolbarState()
   handleInput()
@@ -85,40 +137,66 @@ const insertQuote = () => {
   const selection = window.getSelection()
   if (selection.rangeCount > 0) {
     const range = selection.getRangeAt(0)
-
+    
+    // 检查是否已经在引用中
+    const container = range.commonAncestorContainer
+    let current = container.nodeType === Node.TEXT_NODE ? container.parentElement : container
+    while (current && current !== editorRef.value) {
+      if (current.tagName === 'BLOCKQUOTE' || (current.classList && current.classList.contains('quote-content'))) return
+      current = current.parentElement
+    }
+    
+    // 检查嵌套限制
+    if (isInListOrQuote()) return
+    
     // 创建引用容器
     const quoteContainer = document.createElement('div')
     quoteContainer.className = 'quote-container'
-
+    
     // 创建图标元素
     const icon = document.createElement('img')
     icon.className = 'quote-icon'
     icon.src = '/assets/icons/drawable-xxhdpi/rag_quote.png'
     icon.alt = '引用'
-
+    
     // 创建内容容器
     const contentSpan = document.createElement('blockquote')
     contentSpan.className = 'quote-content'
     contentSpan.textContent = '引用内容'
-
+    
     // 组装元素
     quoteContainer.appendChild(icon)
     quoteContainer.appendChild(contentSpan)
-
+    
     // 插入到当前光标位置
     range.insertNode(quoteContainer)
-
+    
     // 添加换行
     const br = document.createElement('br')
     quoteContainer.parentNode.insertBefore(br, quoteContainer.nextSibling)
-
+    
     // 聚焦到内容区域
     const newRange = document.createRange()
     newRange.selectNodeContents(contentSpan)
     newRange.collapse(false)
     selection.removeAllRanges()
     selection.addRange(newRange)
-
+    
+    // 添加事件监听器到内容区域，监听内容变化
+    const checkContent = () => {
+      // 延迟检查，确保内容已更新
+      setTimeout(() => {
+        if (contentSpan.textContent.trim() === '') {
+          // 如果内容为空，移除整个引用容器
+          quoteContainer.remove()
+          handleInput()
+        }
+      }, 0)
+    }
+    
+    contentSpan.addEventListener('input', checkContent)
+    contentSpan.addEventListener('blur', checkContent)
+    
     handleInput()
   }
 }
@@ -129,6 +207,9 @@ const insertTodoList = () => {
   if (selection.rangeCount > 0) {
     const range = selection.getRangeAt(0)
 
+    // 检查嵌套限制
+    if (isInListOrQuote()) return
+
     // 创建待办事项容器
     const todoContainer = document.createElement('div')
     todoContainer.contentEditable = false
@@ -179,7 +260,7 @@ const insertTodoList = () => {
       handleInput()
     })
 
-    // 添加事件监听器到内容区域，监听内容变化
+    // 添加事件监听器到内容区域，监听内容变化和按键事件
     const checkContent = () => {
       // 延迟检查，确保内容已更新
       setTimeout(() => {
@@ -194,6 +275,150 @@ const insertTodoList = () => {
     contentSpan.addEventListener('input', checkContent)
     contentSpan.addEventListener('blur', checkContent)
 
+    // 监听回车键，创建同级待办事项
+    contentSpan.addEventListener('keydown', e => {
+      if (e.key === 'Enter') {
+        e.preventDefault()
+
+        // 创建新的待办事项
+        const newTodoContainer = document.createElement('div')
+        newTodoContainer.contentEditable = false
+        newTodoContainer.className = 'todo-container'
+
+        // 创建图标元素
+        const newIcon = document.createElement('img')
+        newIcon.className = 'todo-icon'
+        newIcon.src = '/assets/icons/drawable-xxhdpi/rtf_icon_gtasks.png'
+        newIcon.alt = '待办事项'
+
+        // 创建内容容器
+        const newContentSpan = document.createElement('span')
+        newContentSpan.contentEditable = true
+        newContentSpan.className = 'todo-content'
+        newContentSpan.textContent = ''
+
+        // 组装元素
+        newTodoContainer.appendChild(newIcon)
+        newTodoContainer.appendChild(newContentSpan)
+
+        // 插入到当前待办事项后面
+        todoContainer.parentNode.insertBefore(newTodoContainer, todoContainer.nextSibling)
+
+        // 添加换行
+        const newBr = document.createElement('br')
+        newTodoContainer.parentNode.insertBefore(newBr, newTodoContainer.nextSibling)
+
+        // 聚焦到新内容区域
+        const newRange = document.createRange()
+        newRange.selectNodeContents(newContentSpan)
+        newRange.collapse(false)
+        selection.removeAllRanges()
+        selection.addRange(newRange)
+
+        // 添加事件监听器到新图标
+        newIcon.addEventListener('click', function () {
+          // 根据当前状态切换图标
+          if (this.src.includes('rtf_icon_gtasks.png')) {
+            this.src = '/assets/icons/drawable-xxhdpi/rtf_icon_gtasks_light.png'
+            newContentSpan.style.color = 'var(--text-tertiary)'
+            newContentSpan.style.textDecoration = 'line-through'
+          } else {
+            this.src = '/assets/icons/drawable-xxhdpi/rtf_icon_gtasks.png'
+            newContentSpan.style.color = 'var(--note-content)'
+            newContentSpan.style.textDecoration = 'none'
+          }
+          handleInput()
+        })
+
+        // 添加事件监听器到新内容区域
+        const newCheckContent = () => {
+          setTimeout(() => {
+            if (newContentSpan.textContent.trim() === '') {
+              newTodoContainer.remove()
+              handleInput()
+            }
+          }, 0)
+        }
+
+        newContentSpan.addEventListener('input', newCheckContent)
+        newContentSpan.addEventListener('blur', newCheckContent)
+
+        // 监听新内容区域的回车键
+        newContentSpan.addEventListener('keydown', e => {
+          if (e.key === 'Enter') {
+            e.preventDefault()
+
+            // 创建新的待办事项
+            const nextTodoContainer = document.createElement('div')
+            nextTodoContainer.contentEditable = false
+            nextTodoContainer.className = 'todo-container'
+
+            // 创建图标元素
+            const nextIcon = document.createElement('img')
+            nextIcon.className = 'todo-icon'
+            nextIcon.src = '/assets/icons/drawable-xxhdpi/rtf_icon_gtasks.png'
+            nextIcon.alt = '待办事项'
+
+            // 创建内容容器
+            const nextContentSpan = document.createElement('span')
+            nextContentSpan.contentEditable = true
+            nextContentSpan.className = 'todo-content'
+            nextContentSpan.textContent = ''
+
+            // 组装元素
+            nextTodoContainer.appendChild(nextIcon)
+            nextTodoContainer.appendChild(nextContentSpan)
+
+            // 插入到当前待办事项后面
+            newTodoContainer.parentNode.insertBefore(nextTodoContainer, newTodoContainer.nextSibling)
+
+            // 添加换行
+            const nextBr = document.createElement('br')
+            nextTodoContainer.parentNode.insertBefore(nextBr, nextTodoContainer.nextSibling)
+
+            // 聚焦到新内容区域
+            const nextRange = document.createRange()
+            nextRange.selectNodeContents(nextContentSpan)
+            nextRange.collapse(false)
+            selection.removeAllRanges()
+            selection.addRange(nextRange)
+
+            // 添加事件监听器到新图标
+            nextIcon.addEventListener('click', function () {
+              // 根据当前状态切换图标
+              if (this.src.includes('rtf_icon_gtasks.png')) {
+                this.src = '/assets/icons/drawable-xxhdpi/rtf_icon_gtasks_light.png'
+                nextContentSpan.style.color = 'var(--text-tertiary)'
+                nextContentSpan.style.textDecoration = 'line-through'
+              } else {
+                this.src = '/assets/icons/drawable-xxhdpi/rtf_icon_gtasks.png'
+                nextContentSpan.style.color = 'var(--note-content)'
+                nextContentSpan.style.textDecoration = 'none'
+              }
+              handleInput()
+            })
+
+            // 添加事件监听器到新内容区域
+            const nextCheckContent = () => {
+              setTimeout(() => {
+                if (nextContentSpan.textContent.trim() === '') {
+                  nextTodoContainer.remove()
+                  handleInput()
+                }
+              }, 0)
+            }
+
+            nextContentSpan.addEventListener('input', nextCheckContent)
+            nextContentSpan.addEventListener('blur', nextCheckContent)
+
+            handleInput()
+          }
+        })
+
+        handleInput()
+      }
+    })
+
     handleInput()
   }
 }
@@ -364,18 +589,18 @@ defineExpose({
 }
 
 /* 自定义内容样式 */
-.editor-content h2 {
+:deep(.editor-content h2) {
   font-size: 20px;
   font-weight: 600;
-  margin: 16px 0 8px 0;
+  margin: 8px 0 8px 0;
   color: var(--note-title);
   line-height: 1.4;
   letter-spacing: 0.5px;
-  padding-left: 24px;
+  text-align: center;
   position: relative;
 }
 
-.editor-content blockquote {
+:deep(.editor-content blockquote) {
   border-left: 3px solid var(--primary);
   padding-left: 16px;
   margin: 16px 0;
@@ -386,12 +611,12 @@ defineExpose({
   font-style: italic;
 }
 
-.quote-container {
+:deep(.quote-container) {
   position: relative;
   margin: 16px 0;
 }
 
-.quote-icon {
+:deep(.quote-icon) {
   position: absolute;
   left: 0;
   top: 10px;
@@ -399,7 +624,7 @@ defineExpose({
   height: 16px;
 }
 
-.quote-content {
+:deep(.quote-content) {
   border-left: 3px solid var(--primary);
   padding-left: 32px;
   margin-left: 16px;
@@ -410,40 +635,40 @@ defineExpose({
   font-style: italic;
 }
 
-.editor-content ul,
-.editor-content ol {
+:deep(.editor-content ul),
+:deep(.editor-content ol) {
   margin: 16px 0;
   padding-left: 32px;
   position: relative;
 }
 
-.editor-content li {
+:deep(.editor-content li) {
   margin: 6px 0;
   line-height: 1.5;
 }
 
-.editor-content p {
+:deep(.editor-content p) {
   margin: 0 0 12px 0;
   line-height: 1.6;
   letter-spacing: 0.3px;
 }
 
-.editor-content strong {
+:deep(.editor-content strong) {
   color: var(--text-primary);
   font-weight: 600;
 }
 
-.editor-content em {
+:deep(.editor-content em) {
   color: var(--text-secondary);
   font-style: italic;
 }
 
-.editor-content u {
+:deep(.editor-content u) {
   text-decoration: none;
   border-bottom: 1px solid var(--text-primary);
 }
 
-.editor-content hr {
+:deep(.editor-content hr) {
   border: none;
   height: 1px;
   background-color: var(--border);
@@ -458,16 +683,16 @@ defineExpose({
 :deep(.todo-container) {
   display: flex;
   align-items: flex-start;
-  margin: 0.5rem 0;
-  padding: 0.25rem 0;
+  margin: 0.1rem 0;
+  padding: 0.02rem 0;
   position: relative;
-  padding-left: 1.5rem;
+  padding-left: 1.2rem;
 }
 
 :deep(.todo-icon) {
   position: absolute;
   left: 0;
-  top: 0.2rem;
+  top: 0;
   width: 2rem;
   height: 2rem;
   cursor: pointer;
@@ -507,57 +732,4 @@ defineExpose({
   border-radius: 0 0.25rem 0.25rem 0;
   font-style: italic;
 }
-
-/* 格式标识图标 */
-.editor-content h2::before {
-  content: '';
-  display: inline-block;
-  width: 16px;
-  height: 16px;
-  background-image: url('/assets/icons/drawable-xxhdpi/rtf_header_normal.9.png');
-  background-size: contain;
-  background-repeat: no-repeat;
-  position: absolute;
-  left: 0;
-  top: 2px;
-}
-
-.editor-content blockquote::before {
-  content: '';
-  display: inline-block;
-  width: 16px;
-  height: 16px;
-  background-image: url('/assets/icons/drawable-xxhdpi/rtf_quot_normal.9.png');
-  background-size: contain;
-  background-repeat: no-repeat;
-  position: absolute;
-  left: 8px;
-  top: 10px;
-}
-
-.editor-content ul::before {
-  content: '';
-  display: inline-block;
-  width: 16px;
-  height: 16px;
-  background-image: url('/assets/icons/drawable-xxhdpi/rtf_list_normal.9.png');
-  background-size: contain;
-  background-repeat: no-repeat;
-  position: absolute;
-  left: 0;
-  top: 2px;
-}
-
-.editor-content ol::before {
-  content: '';
-  display: inline-block;
-  width: 16px;
-  height: 16px;
-  background-image: url('/assets/icons/drawable-xxhdpi/rtf_list_normal.9.png');
-  background-size: contain;
-  background-repeat: no-repeat;
-  position: absolute;
-  left: 0;
-  top: 2px;
-}
 </style>