diff --git a/app/test/test_bug551_DingZeYu.py b/app/test/test_bug551_DingZeYu.py
index 7351dfe..7c254c5 100644
--- a/app/test/test_bug551_DingZeYu.py
+++ b/app/test/test_bug551_DingZeYu.py
@@ -22,4 +22,12 @@ def test_bug551(driver, URL):
     actions.move_by_offset(450, 200)
     actions.release()
     actions.perform()
+
+    # 获取选中部分的单词所应用的 CSS 样式
+    highlighted_word_font_weight = article.value_of_css_property("font-weight")
+    
+    # 验证高亮显示的 CSS 样式是否符合预期
+    expected_highlighted_word_font_weight = "300"
+    assert highlighted_word_font_weight == expected_highlighted_word_font_weight, f"选中部分的单词的字体样式错误"
+
     time.sleep(5)
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