body {
  font-family: "Segoe UI", sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
  background: #f8f9fa;
  color: #333;
  display: flex;
}

/* Navbar */
#navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 250px;
  height: 100%;
  background: linear-gradient(180deg, #4b6cb7, #182848);
  color: white;
  padding: 20px;
  box-shadow: 2px 0 8px rgba(0,0,0,0.2);
}

#navbar header {
  font-size: 1.5em;
  margin-bottom: 20px;
  font-weight: bold;
  animation: fadeInDown 1s ease;
}

#navbar a {
  display: block;
  color: white;
  text-decoration: none;
  margin: 10px 0;
  padding: 8px;
  border-radius: 6px;
  transition: background 0.3s ease;
}

#navbar a:hover {
  background: rgba(255,255,255,0.2);
}

/* Main content */
#main-doc {
  margin-left: 270px;
  padding: 20px;
  flex: 1;
}

section {
  margin-bottom: 50px;
  padding: 20px;
  background: white;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  animation: fadeInUp 0.8s ease;
}

section header {
  font-size: 1.3em;
  font-weight: bold;
  margin-bottom: 10px;
  color: #182848;
}

code {
  display: block;
  background: #f1f1f1;
  padding: 6px;
  margin: 6px 0;
  border-radius: 6px;
  font-family: monospace;
}

/* Animations */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Responsive design */
@media (max-width: 768px) {
  #navbar {
    position: relative;
    width: 100%;
    height: auto;
    box-shadow: none;
  }
  #main-doc {
    margin-left: 0;
  }
}