diff --git a/playground/src/components/latex-text/index.vue b/playground/src/components/latex-text/index.vue
index 3165021..5ca4ed1 100644
--- a/playground/src/components/latex-text/index.vue
+++ b/playground/src/components/latex-text/index.vue
@@ -20,12 +20,20 @@ const regex_tag = /(<span data-.+?="[^"]*"><\/span>)/g
 // 仅匹配合法 HTML 标签，避免将 $a<b$ 中的 <b 误判为标签并吞掉后续内容
 const regex_html = /(<\/?[a-zA-Z][a-zA-Z0-9]*(?:\s+[^>]*)?\s*>)/g
 
+const regex_html_entity = /&(?:#(?:\d+|x[\da-f]+)|[a-z][\da-z]*);/gi
+
 function escapeHtml(text: string) {
-  return text
+  const entities: string[] = []
+  const protectedText = text.replace(regex_html_entity, (entity) => {
+    entities.push(entity)
+    return `\uE000${entities.length - 1}\uE001`
+  })
+  return protectedText
     .replaceAll('&', '&amp;')
     .replaceAll('<', '&lt;')
     .replaceAll('>', '&gt;')
     .replaceAll('"', '&quot;')
+    .replace(/\uE000(\d+)\uE001/g, (_, index) => entities[Number(index)]!)
 }
 
 function addLatexText(list: any[], text: string) {
diff --git a/playground/src/components/paper-question-item/index.vue b/playground/src/components/paper-question-item/index.vue
index 7c46912..c7398b0 100644
--- a/playground/src/components/paper-question-item/index.vue
+++ b/playground/src/components/paper-question-item/index.vue
@@ -770,10 +770,13 @@ const handleEditSave = async () => {
 
   .qml-bk {
     display: inline-block;
-    line-height: 0.8;
+    min-width: 2em;
+    padding: 0 2px;
+    line-height: inherit;
+    vertical-align: baseline;
     text-align: center;
     overflow-wrap: break-word;
-    text-decoration-color: unset !important;
+    text-decoration: none !important;
     background-color: #ecf9ff;
     border-bottom: 1px solid #000;
   }