Develop a simple web page for uploading and displaying images. Your task includes the following steps:
- Create an HTML form for uploading images to the server.
- Write a PHP script to handle the uploaded image and save it on the server.
- Display the uploaded image on the page after a successful upload.
Requirements:
- Use PHP to handle image upload and display.
- Ensure security checks for uploaded files.
- Make the page visually appealing using HTML and CSS.