style.css

* {
	box-sizing: border-box;
	margin: 0;
	padding: 0;
  }
  
  body {
	font-family: Arial, sans-serif;
	font-size: 16px;
	line-height: 1.5;
	background-color: white;
	color: black;
  }
  
  body.dark-mode {
	background-color: black;
	color: white;
  }
  
  header,
  nav ul,
  nav li,
  nav a,
  main,
  section,
  section h2,
  footer {
	background-color: white;
	color: black;
  }
  
  header.dark-mode,
  nav ul.dark-mode,
  nav li.dark-mode,
  nav a.dark-mode,
  main.dark-mode,
  section.dark-mode,
  section h2.dark-mode,
  footer.dark-mode {
	background-color: black;
	color: white;
  }
  
  header {
	padding: 20px;
  }
  
  header h1 {
	font-size: 36px;
	margin: 0;
  }
  
  nav ul {
	list-style: none;
	display: flex;
	justify-content: space-between;
	align-items: center;
	margin-top: 10px;
  }
  
  nav li {
	margin: 0 10px;
  }
  
  nav a {
	text-decoration: none;
	color: #333;
	padding: 10px;
  }
  
  nav a:hover {
	background-color: #333;
	color: white;
  }
  
  main {
	padding: 20px;
  }
  
  section {
	margin-bottom: 20px;
  }
  
  section h2 {
	font-size: 24px;
	margin-bottom: 10px;
  }
  
  footer {
	padding: 20px;
	text-align: center;
  }
  
  .dark-mode nav a:hover {
	background-color: white;
	color: black;
  }