body {
  font-family: 'Comic Sans MS', cursive, sans-serif;
  margin: 0;
  background: #f0f4f8;
  color: #333;
}

header .top-banner {
  background: #1e90ff;
  color: white;
  display: flex;
  align-items: center;
  padding: 15px;
}

header .top-banner .logo {
  height: 50px;
  margin-right: 15px;
}

header h1 {
  font-size: 2em;
  margin: 0;
}

.sidebar {
  position: fixed;
  top: 80px;
  left: 0;
  width: 220px;
  background: #add8e6;
  height: 100%;
  padding: 15px;
  box-sizing: border-box;
}

.sidebar h2 {
  font-size: 1.2em;
}

.sidebar ul {
  list-style: none;
  padding: 0;
}

.sidebar li {
  margin: 10px 0;
}

.sidebar a {
  text-decoration: none;
  color: #00008b;
  font-weight: bold;
}

.sidebar a:hover {
  text-decoration: underline;
}

main {
  margin-left: 240px;
  padding: 20px;
}

footer {
  margin-left: 240px;
  background: #ddd;
  padding: 10px;
  text-align: center;
  font-size: 14px;
}

@media (max-width: 768px) {
  .sidebar {
    position: relative;
    width: 100%;
    height: auto;
  }
  main {
    margin-left: 0;
  }
}