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

body {
  font-family: Arial, sans-serif;
  font-size: 16px;
  color: #333;
}

header {
  background-color: #333;
  height: 80px;
  display: flex;
  align-items: center;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1;
}

.logo {
  flex: 1;
  margin-left: 20px;
}

.logo img {
  height: 60px;
}

nav {
  flex: 3;
}

nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  justify-content: flex-end;
}

nav ul li {
  margin-left: 20px;
}

nav ul li a {
  display: block;
  padding: 0 10px;
  line-height: 80px;
  color: #fff;
  text-decoration: none;
  font-weight: bold;
  transition: background-color 0.3s ease;
}

nav ul li a:hover {
  background-color: #666;
}

#contenido {
  margin-top: 100px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

section {
  display: none;
}

section:target {
  display: block;
}