header { 
  background: rgba(255, 255, 255, 0.95); 
  backdrop-filter: blur(10px); 
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1); 
  position: sticky; top: 0; z-index: 100; 
  display: flex; justify-content: space-between; align-items: center; 
  padding: 0.5rem 1rem;
}
.logo img { height: 50px; }
nav { position: relative; }
.nav-links { display: flex; list-style: none; gap: 2rem; }
.nav-links a { text-decoration: none; color: #4a5568; font-weight: 500; transition: all 0.3s ease; padding: 0.5rem 1rem; border-radius: 8px; }
.nav-links a:hover { background: #667eea; color: white; transform: translateY(-2px); }
.hamburger { display: none; flex-direction: column; cursor: pointer; gap: 5px; }
.hamburger div { width: 25px; height: 3px; background: #333; border-radius: 2px; }
@media (max-width: 768px) {
  .nav-links { position: absolute; top: 60px; right: 0; background: white; flex-direction: column; width: 200px; padding: 1rem; box-shadow: 0 5px 15px rgba(0,0,0,0.2); display: none; }
  .nav-links.active { display: flex; }
  .hamburger { display: flex; }
}