This situation was most likely due to the visual illusion caused by word games or magic effects in the novel. Word games usually created interesting visual effects by adding special symbols or expressions to the text. For example, in a novel, some symbols or expressions might be used to change the color or size of the font to make the text look like it had changed. Magic effects could also be the cause of the changes in the text. For example, in some novels, magic might appear to change the color of the text or make the text seem to float in the air. If you often encounter changes in the text when reading a novel, you can try to pause the novel and carefully check if the text has changed. You can also try adjusting the font size and color of the browser to see if the text will change.