<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8" /> <title>Bitburner</title> <style> body { background-color: black; color: #0c0; } div { height: 100vh; display: flex; justify-content: center; align-items: center; } h1 { text-align: center; } </style> </head> <body> <div> <h1>Close me when operation is completed.</h1> </div> </body> </html>