* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, sans-serif;
  color: #333;
}

nav {
  background-color: #2c3e50;
  padding: 15px 20px;
  position: sticky;
  top: 0;
}

nav a {
  color: #ecf0f1;
  text-decoration: none;
  margin-right: 20px;
  font-size: 16px;
}

nav a:hover {
  color: #3498db;
}

header {
  background-color: #3498db;
  color: white;
  padding: 60px 20px;
  text-align: center;
}

section {
  padding: 40px 20px;
}

.light {
  background-color: #ecf0f1;
}

.dark {
  background-color: #bdc3c7;
}

footer {
  background-color: #2c3e50;
  color: #ecf0f1;
  padding: 20px;
  text-align: center;
}