<!DOCTYPE html> <html> <head> <title>History Explorer</title> <style> body { font-family: Arial, sans-serif; line-height: 1.6; margin: 0; padding: 0; background-color: #f4f4f4; color: #333; } header { background: #333; color: #fff; padding: 20px 0; text-align: center; } header h1 { margin: 0; } nav { background: #444; padding: 10px; text-align: center; } nav ul { list-style: none; padding: 0; } nav ul li { display: inline; ...