style(tools): 优化文本比对页布局并修复删除行着色错位

布局优化：
- 操作栏改为「主操作 + 选项组 + 次要操作」三段式，
  勾选项与操作按钮视觉分层，不再混排成一条
- 统计条并入浅色卡片，用 gap 替代多个 flex:1 空白撑开块
- 差异导航加「定位」标签，序号改 tabular-nums 防跳动
- 「重新编辑/导出」并入统计条右侧，释放一行纵向空间
- 表头「行号 行号」改为「原 新」，左右分栏各加竖分隔线
- 输入区行数改为胶囊标签，标题与行数两端对齐

修复：
- 删除行红底打错列：原 :first-of-type 因前置 .cell-no 兄弟而选不中，
  改为显式 col-left / col-right 类名，新增/删除/修改各自单侧或双侧着色
- 只看差异在无结果时禁用（此前点了无反应），清空时重置该状态
- 导出 HTML 的着色规则与页面保持一致，并支持字符级 <mark> 高亮

交互：
- 新增 Ctrl/Cmd+Enter 触发比对、Esc 返回编辑
- 键盘监听仅在 activated 注册，避免 keep-alive 下重复绑定导致按键触发多次

src/view/tools/text-diff.vue

@@ -2,42 +2,68 @@
   <div class="text-diff-page">
     <!-- 操作栏 start -->
     <div class="diff-toolbar">
-      <Button type="primary" icon="md-git-compare" :loading="comparing" @click="doCompare()">比对</Button>
+      <!-- 主操作 -->
+      <Tooltip content="开始比对（Ctrl + Enter）" transfer>
+        <Button type="primary" icon="md-git-compare" :loading="comparing" @click="doCompare()">开始比对</Button>
+      </Tooltip>
+
+      <!-- 视图选项：与操作按钮视觉分层 -->
+      <div class="toolbar-group">
         <Checkbox v-model="ignoreWhitespace">忽略空白</Checkbox>
-      <Checkbox v-model="onlyChanges">只看差异</Checkbox>
+        <Checkbox v-model="onlyChanges" :disabled="!hasResult">只看差异</Checkbox>
+      </div>
+
       <div class="toolbar-gap"></div>
+
+      <!-- 次要操作 -->
+      <div class="toolbar-group">
+        <Tooltip content="交换左右两侧内容" transfer>
           <Button icon="md-swap" :disabled="comparing" @click="swapSides()">交换</Button>
-      <Button icon="md-trash" :disabled="comparing" @click="clearAll()">清空</Button>
+        </Tooltip>
+        <Tooltip content="填充一组示例数据" transfer>
           <Button icon="md-flask" :disabled="comparing" @click="fillSample()">示例</Button>
-      <Button icon="md-download" :disabled="!hasResult" @click="exportHtml()">导出</Button>
+        </Tooltip>
+        <Button icon="md-trash" :disabled="comparing" @click="clearAll()">清空</Button>
+      </div>
     </div>
     <!-- 操作栏 end -->
 
     <!-- 统计条 start -->
     <div class="diff-stats" v-if="hasResult">
-      <span class="stat-item">
-        <span class="stat-dot added-dot"></span>新增 <b class="stat-num added-text">{{ stats.added }}</b> 行
+      <div class="stat-group">
+        <span class="stat-item added-item">
+          <i class="stat-dot"></i>新增<b class="stat-num">{{ stats.added }}</b>
         </span>
-      <span class="stat-item">
-        <span class="stat-dot removed-dot"></span>删除 <b class="stat-num removed-text">{{ stats.removed }}</b> 行
+        <span class="stat-item removed-item">
+          <i class="stat-dot"></i>删除<b class="stat-num">{{ stats.removed }}</b>
         </span>
-      <span class="stat-item">
-        <span class="stat-dot changed-dot"></span>修改 <b class="stat-num changed-text">{{ stats.changed }}</b> 行
+        <span class="stat-item changed-item">
+          <i class="stat-dot"></i>修改<b class="stat-num">{{ stats.changed }}</b>
         </span>
-      <span class="stat-item muted">相同 {{ stats.unchanged }} 行</span>
-      <div class="toolbar-gap"></div>
-      <span class="stat-item muted" v-if="elapsed">耗时 {{ elapsed }} ms</span>
-      <template v-if="changeRows.length > 0">
-        <div class="toolbar-gap"></div>
-        <span class="stat-item nav-group">
+        <span class="stat-item plain-item">相同<b class="stat-num">{{ stats.unchanged }}</b></span>
+      </div>
+
+      <div class="stat-divider" v-if="changeRows.length > 0"></div>
+
+      <!-- 差异导航 -->
+      <div class="nav-group" v-if="changeRows.length > 0">
+        <span class="nav-label">定位</span>
         <Button size="small" icon="md-arrow-up" :disabled="navIndex <= 0" @click="gotoChange(-1)"></Button>
-          <span class="nav-text">{{ navIndex + 1 }} / {{ changeRows.length }}</span>
+        <span class="nav-text">{{ navIndex + 1 }}<em>/</em>{{ changeRows.length }}</span>
         <Button size="small" icon="md-arrow-down" :disabled="navIndex >= changeRows.length - 1" @click="gotoChange(1)"></Button>
-        </span>
-      </template>
+      </div>
+
       <div class="toolbar-gap"></div>
+
+      <div class="stat-group right-group">
+        <span class="stat-item plain-item" v-if="elapsed">耗时{{ elapsed }} ms</span>
         <Tag v-if="hasDiff" type="warning">存在差异</Tag>
         <Tag v-else type="success">完全一致</Tag>
+        <Button size="small" icon="md-create" @click="backToEdit()">重新编辑</Button>
+        <Tooltip content="导出为带颜色标记的 HTML 文件" transfer>
+          <Button size="small" icon="md-download" :disabled="!hasResult" @click="exportHtml()">导出</Button>
+        </Tooltip>
+      </div>
     </div>
     <!-- 统计条 end -->
 
@@ -75,18 +101,14 @@
 
     <!-- 结果区 start -->
     <div class="diff-result-area" v-if="hasResult">
-      <div class="result-toolbar">
-        <Button size="small" icon="md-create" @click="backToEdit()">重新编辑</Button>
-        <span class="result-hint">左侧为原始内容，右侧为对比内容</span>
-      </div>
       <div class="diff-table-wrap">
         <div class="diff-table">
           <div class="diff-row diff-head-row">
-            <div class="cell-no">行号</div>
-            <div class="cell-no">行号</div>
+            <div class="cell-no">原</div>
+            <div class="cell-no col-right">新</div>
             <div class="cell-mark"></div>
-            <div class="cell-text">原始内容</div>
-            <div class="cell-text">对比内容</div>
+            <div class="cell-text col-left">原始内容</div>
+            <div class="cell-text col-right">对比内容</div>
           </div>
           <div v-for="(row, idx) in visibleRows"
                :key="idx"
@@ -94,9 +116,9 @@
                :class="[rowClass(row), { active: activeRowIndex === idx }]"
                :ref="'row' + idx">
             <div class="cell-no">{{ row.leftNo > 0 ? row.leftNo : '' }}</div>
-            <div class="cell-no">{{ row.rightNo > 0 ? row.rightNo : '' }}</div>
+            <div class="cell-no col-right">{{ row.rightNo > 0 ? row.rightNo : '' }}</div>
             <div class="cell-mark"></div>
-            <div class="cell-text">
+            <div class="cell-text col-left">
               <template v-if="row.leftParts">
                 <span v-for="(part, k) in row.leftParts"
                       :key="'l' + k"
@@ -104,7 +126,7 @@
               </template>
               <span v-else class="placeholder-text">—</span>
             </div>
-            <div class="cell-text">
+            <div class="cell-text col-right">
               <template v-if="row.rightParts">
                 <span v-for="(part, k) in row.rightParts"
                       :key="'r' + k"
@@ -216,6 +238,7 @@
       clearAll () {
         this.leftText = ''
         this.rightText = ''
+        this.onlyChanges = false
         this.backToEdit()
       },
       swapSides () {
@@ -322,15 +345,27 @@
       exportHtml () {
         const rows = this.rows
         let body = ''
+        // 与页面保持一致：新增只染右栏、删除只染左栏、修改两侧都染
+        const cellClass = row => {
+          if (row.type === 'insert') return 'txt side-right hit'
+          if (row.type === 'delete') return 'txt side-left hit'
+          if (row.type === 'replace') return 'txt hit'
+          return 'txt'
+        }
+        const renderParts = parts => {
+          if (!parts) return '<span class="ph">—</span>'
+          return parts.map(p => {
+            const text = escapeHtml(p.text)
+            return p.changed ? '<mark>' + text + '</mark>' : text
+          }).join('')
+        }
         rows.forEach(row => {
           const cls = this.rowClass(row)
-          const left = row.leftParts ? row.leftParts.map(p => escapeHtml(p.text)).join('') : ''
-          const right = row.rightParts ? row.rightParts.map(p => escapeHtml(p.text)).join('') : ''
           body += '<tr class="' + cls + '">'
           body += '<td class="no">' + (row.leftNo > 0 ? row.leftNo : '') + '</td>'
           body += '<td class="no">' + (row.rightNo > 0 ? row.rightNo : '') + '</td>'
-          body += '<td class="txt">' + left + '</td>'
-          body += '<td class="txt">' + right + '</td>'
+          body += '<td class="' + cellClass(row) + ' side-left">' + renderParts(row.leftParts) + '</td>'
+          body += '<td class="' + cellClass(row) + ' side-right">' + renderParts(row.rightParts) + '</td>'
           body += '</tr>'
         })
         const html = '<!DOCTYPE html><html lang="zh-CN"><head><meta charset="utf-8">'
@@ -339,16 +374,19 @@
           + '.bar{padding:10px 12px;background:#f0f3fa;border-radius:6px;margin-bottom:12px}'
           + 'table{border-collapse:collapse;width:100%;table-layout:fixed}'
           + 'td{border:1px solid #e8eaec;padding:2px 6px;vertical-align:top;white-space:pre-wrap;word-break:break-all}'
-          + 'td.no{width:48px;background:#f8f8f9;color:#808695;text-align:right;user-select:none}'
-          + 'td.txt{width:40%}'
-          + 'tr.row-insert td{background:#e8f8ee}'
-          + 'tr.row-delete td{background:#fdecec}'
+          + 'td.no{width:44px;background:#f8f8f9;color:#808695;text-align:right;user-select:none;font-variant-numeric:tabular-nums}'
+          + 'td.txt{width:41%}'
+          + 'td.side-left{border-right:1px solid #dcdee2}'
+          + 'tr.row-insert td.side-right{background:#e8f8ee}'
+          + 'tr.row-delete td.side-left{background:#fdecec}'
           + 'tr.row-replace td{background:#fff8e1}'
+          + 'mark{background:#e6a23c;color:#fff;border-radius:2px;padding:0 1px}'
+          + 'span.ph{color:#c5c8ce}'
           + '</style></head><body>'
           + '<div class="bar">新增 ' + this.stats.added + ' 行 ｜ 删除 ' + this.stats.removed
           + ' 行 ｜ 修改 ' + this.stats.changed + ' 行 ｜ 相同 ' + this.stats.unchanged + ' 行</div>'
-          + '<table><tr><td class="no">行</td><td class="no">行</td><td class="txt">原始内容</td>'
-          + '<td class="txt">对比内容</td></tr>' + body + '</table></body></html>'
+          + '<table><tr><td class="no">原</td><td class="no">新</td><td class="txt side-left">原始内容</td>'
+          + '<td class="txt side-right">对比内容</td></tr>' + body + '</table></body></html>'
 
         this.downloadFile('text-diff-result.html', html, 'text/html')
       },
@@ -362,7 +400,32 @@
         a.click()
         document.body.removeChild(a)
         URL.revokeObjectURL(url)
+      },
+      // Ctrl/Cmd + Enter 触发比对；输入框内换行不受影响
+      onKeydown (event) {
+        const isCompare = (event.ctrlKey || event.metaKey) && event.key === 'Enter'
+        if (isCompare) {
+          event.preventDefault()
+          if (!this.comparing) this.doCompare()
+          return
         }
+        // Esc 退出结果视图
+        if (event.key === 'Escape' && this.hasResult) {
+          this.backToEdit()
+        }
+      }
+    },
+    // keep-alive 下 mounted 与 activated 都会触发，同一函数重复 addEventListener
+    // 会导致一次按键触发多次，因此只放在 activated 注册，deactivated 统一解绑
+    activated () {
+      window.removeEventListener('keydown', this.onKeydown)
+      window.addEventListener('keydown', this.onKeydown)
+    },
+    deactivated () {
+      window.removeEventListener('keydown', this.onKeydown)
+    },
+    beforeDestroy () {
+      window.removeEventListener('keydown', this.onKeydown)
     }
   }
 
@@ -385,66 +448,115 @@
     display: flex;
     align-items: center;
     flex-wrap: wrap;
+    gap: 12px;
     padding-bottom: 12px;
-    border-bottom: 1px solid #ddd;
+    border-bottom: 1px solid #e8eaec;
   }
 
-  .diff-toolbar .ivu-checkbox-wrapper {
-    margin-right: 16px;
+  // 选项组：浅底 + 圆角，与操作按钮形成视觉分层
+  .toolbar-group {
+    display: inline-flex;
+    align-items: center;
+    gap: 8px;
+    padding: 0 4px;
+    border-radius: 4px;
+  }
+
+  .toolbar-group .ivu-checkbox-wrapper {
+    margin-right: 0;
   }
 
   .toolbar-gap {
     flex: 1;
   }
 
+  // 统计条并入浅色卡片，与内容区形成区块感
   .diff-stats {
     display: flex;
     align-items: center;
     flex-wrap: wrap;
-    padding: 10px 0;
+    gap: 8px 14px;
+    margin-top: 12px;
+    padding: 8px 14px;
+    background: #f7f8fa;
+    border: 1px solid #e8eaec;
+    border-radius: 4px;
     font-size: 13px;
     color: #515a6e;
   }
 
-  .stat-item {
+  .stat-group {
     display: inline-flex;
     align-items: center;
-    margin-right: 18px;
+    gap: 14px;
   }
 
-  .stat-item.muted {
-    color: #808695;
+  .right-group {
+    gap: 10px;
+  }
+
+  .stat-item {
+    display: inline-flex;
+    align-items: baseline;
+    white-space: nowrap;
   }
 
   .stat-dot {
+    align-self: center;
     display: inline-block;
     width: 8px;
     height: 8px;
     border-radius: 2px;
-    margin-right: 6px;
+    margin-right: 5px;
   }
 
-  .added-dot { background: #19be6b; }
-  .removed-dot { background: #ed4014; }
-  .changed-dot { background: #ff9900; }
+  .added-item .stat-dot { background: #19be6b; }
+  .removed-item .stat-dot { background: #ed4014; }
+  .changed-item .stat-dot { background: #ff9900; }
 
-  .stat-num {
-    margin: 0 4px 0 2px;
+  .stat-item b {
+    margin-left: 4px;
     font-size: 14px;
+    font-weight: 600;
   }
 
-  .added-text { color: #19be6b; }
-  .removed-text { color: #ed4014; }
-  .changed-text { color: #ff9900; }
+  .added-item b { color: #19be6b; }
+  .removed-item b { color: #ed4014; }
+  .changed-item b { color: #ff9900; }
 
-  .nav-group .ivu-btn {
-    margin: 0 4px;
+  .plain-item {
+    color: #808695;
+  }
+
+  .stat-divider {
+    width: 1px;
+    height: 16px;
+    background: #dcdee2;
+  }
+
+  // 差异导航
+  .nav-group {
+    display: inline-flex;
+    align-items: center;
+    gap: 4px;
+  }
+
+  .nav-label {
+    color: #808695;
+    margin-right: 2px;
   }
 
   .nav-text {
-    min-width: 54px;
+    min-width: 48px;
     text-align: center;
     font-size: 13px;
+    font-variant-numeric: tabular-nums;
+  }
+
+  .nav-text em {
+    font-style: normal;
+    color: #c5c8ce;
+    margin: 0 2px;
   }
 
   .diff-input-area {
@@ -464,7 +576,8 @@
 
   .input-head {
     display: flex;
-    align-items: baseline;
+    align-items: center;
+    justify-content: space-between;
     padding-bottom: 6px;
   }
 
@@ -475,9 +588,11 @@
   }
 
   .input-meta {
-    margin-left: 8px;
     font-size: 12px;
     color: #808695;
+    background: #f7f8fa;
+    border-radius: 10px;
+    padding: 1px 8px;
   }
 
   .diff-textarea {
@@ -501,18 +616,6 @@
     min-height: 0;
   }
 
-  .result-toolbar {
-    display: flex;
-    align-items: center;
-    padding-bottom: 8px;
-  }
-
-  .result-hint {
-    margin-left: 12px;
-    font-size: 12px;
-    color: #808695;
-  }
-
   .diff-table-wrap {
     flex: 1;
     overflow: auto;
@@ -545,7 +648,7 @@
   }
 
   .cell-no {
-    flex: 0 0 52px;
+    flex: 0 0 48px;
     padding: 3px 8px;
     text-align: right;
     color: #808695;
@@ -554,11 +657,19 @@
     font-size: 12px;
     user-select: none;
     white-space: nowrap;
+    font-variant-numeric: tabular-nums;
+  }
+
+  // 最后一个行号列与色条之间加一条竖分隔，强化左右分栏
+  .cell-no.col-right {
+    border-right: none;
   }
 
   .cell-mark {
     flex: 0 0 4px;
     background: transparent;
+    border-left: 1px solid #dcdee2;
+    border-right: 1px solid #dcdee2;
   }
 
   .cell-text {
@@ -570,15 +681,22 @@
     line-height: 1.6;
     white-space: pre-wrap;
     word-break: break-all;
-    border-right: 1px solid #f0f2f5;
+  }
+
+  // 左右两栏之间用竖线分隔，长文本下更易对照
+  .cell-text.col-left {
+    border-right: 1px solid #dcdee2;
   }
 
   .diff-row.row-insert .cell-mark { background: #19be6b; }
   .diff-row.row-delete .cell-mark { background: #ed4014; }
   .diff-row.row-replace .cell-mark { background: #ff9900; }
 
-  .diff-row.row-insert .cell-text:last-child { background: #e8f8ee; }
-  .diff-row.row-delete .cell-text:first-of-type { background: #fdecec; }
+  // 新增：仅右侧栏着色
+  .diff-row.row-insert .cell-text.col-right { background: #e8f8ee; }
+  // 删除：仅左侧栏着色
+  .diff-row.row-delete .cell-text.col-left { background: #fdecec; }
+  // 修改：两侧都着色
   .diff-row.row-replace .cell-text { background: #fff8e1; }
 
   .diff-row.active .cell-text {