body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
}

header {
  background-color: #000000;
  color: white;
  text-align: center;
  padding: 1rem 0;
}

.container {
  display: flex;
  height: 100vh;
}

nav {
  width: 250px;
  background: #f4f4f4;
  padding: 20px;
  box-shadow: 2px 0 5px rgba(0, 0, 0, 0.1);
}

nav ul {
  list-style: none;
  padding: 0;
}

nav li {
  margin-bottom: 10px;
}

nav a {
  text-decoration: none;
  color: #333;
  display: block;
  padding: 10px;
  border-radius: 5px;
}

nav a:hover {
  background: #ddd;
}

main {
  flex-grow: 1;
  padding: 20px;
}

zero-md {
  display: block;
}