Simple explanation
When you say "make my UI better" to Claude, it does not know what you mean. It might rewrite your entire screen layout, change your color scheme, restructure your components, or add new libraries. That is a lot of risk. Good UI improvements are surgical, not wholesale.
What to do
Describe one specific visual problem: "The button looks too small on mobile." Paste only the code for that button. Ask Claude to fix only that element. Do not paste your entire screen or layout file.
Copy-paste prompt
Here is the code for [specific UI element]. The problem is: [describe the visual issue precisely]. Please fix only this element. Do not change the screen structure, the overall color scheme, or any other component.
Course note
Key takeaway
Surgical UI fixes only. One element at a time.