Text
In Xmind, elements that can contain Text include all except Labels (in the Matrix structure, Rows are also Labels, hence not considered as Text). All Types of Topics, Relationship, Callout, and Boundary are considered as Text.
Edit Text
Method 1
Double-click the topic to enter edit mode.
Method 2
Select the topic and press the Space key to edit.
Note: When creating a Topic, it will default to having text of the topic type, such as Central Topic, Main Topic, Subtopic, or Floating Topic.
Adjust Text
Single Topic
Click on the topic, and click on Format > Style > Text, and you can adjust the font, size, color, format, and alignment.

Multiple Topics
Method 1
Drag your mouse to select the topics you want to adjust.
Click on Format > Style > Text to adjust the font, size, color, format, and alignment.
Method 2
Click on one of the topics you want to adjust, and click on Format > Style > Text, you can adjust the font, size, color, format, and alignment.
Click on Format > Style > Update and choose Update to All Level x Topics or Update to All Subtopics (x is the number of subtopic levels).

Note:
Text styles include: bold, italics, strikethrough, and capitalization.

Delete Text
Method 1
Enter edit mode and press the Delete key.
Method 2
Right-click on the topic and click Clear Text.

Rich-style Text
What is Rich-style Text?
Xmind topics support setting diverse styles for parts of the text, allowing individual style settings for portions of the text to make important sections stand out.
Note: Rich-style text is built based on text editing; select part of the text for editing.
Edit Rich-style Text
After editing the text in a single topic, use the mouse to select the part of the text that needs a change in format.
Click on Format > Style > Text to adjust the font, size, color, and text formats such as bold, italic, and strikethrough.

Delete Rich-style Text
Method 1
Click on Menu > Edit > Undo to revert to the previous step.

Method 2
Use the shortcut:
Windows:Ctrl+z
Mac:⌘+z
Method 3
Use the mouse to select the part of the text you wish to revert, and manually adjust to the original format in Format > Style > Text.