Update README.md

Removed duplicate image tag and adjusted alignment.

Author: upeka200163

README.md

@@ -14,11 +14,8 @@ Smart Calculator is a lightweight and responsive web application designed to per
 
 ## 📸 Project Preview
 
-<img width="1366" height="642" alt="471041056-0d0fa4cc-12cd-415d-915a-d2fffa599732" src="https://github.com/user-attachments/assets/c73b22d5-453a-4235-9dbc-b51d28362f50" />
-
-
 <p align="center">
-  <img src="https://github.com/user-attachments/assets/YOUR_IMAGE_LINK" width="900" alt="Calculator Preview"/>
+<img width="1366" height="642" alt="471041056-0d0fa4cc-12cd-415d-915a-d2fffa599732" src="https://github.com/user-attachments/assets/c73b22d5-453a-4235-9dbc-b51d28362f50" />
 </p>
 
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