<!DOCTYPE html> <html lang="en"> <meta charset="utf-8"> <title>The div should have a white filling.</title> <style> html, body { margin: 0; padding: 0; } html { background-color: white; } body { padding: 10px; } div { width: 50px; height: 50px; box-sizing: border-box; border: 1px solid black; } </style> <div></div>