/* style.css */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.8;
  color: #2d3748;
  background: #f7f9fc;
}

header {
  background: linear-gradient(135deg, #002060 0%, #003399 100%);
  color: white;
  text-align: center;
  padding: 2.5rem 1.5rem;
}

header h1 {
  font-size: 1.8rem;
  margin-bottom: 0.3rem;
}

header p {
  font-size: 1rem;
  opacity: 0.9;
}

nav {
  background: white;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  padding: 0.8rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

nav ul {
  display: flex;
  justify-content: center;
  list-style: none;
  flex-wrap: wrap;
  gap: 2rem;
}

nav a {
  color: #2d3748;
  text-decoration: none;
  font-weight: 500;
  font-size: 1.1rem;
  padding: 0.6rem 1.4rem;
  border-radius: 30px;
  transition: all 0.3s ease;
}

nav a:hover {
  background: #007BFF;
  color: white;
  transform: translateY(-2px);
}

main {
  max-width: 1100px;
  margin: 2.5rem auto;
  padding: 0 2rem;
}

section {
  background: white;
  margin-bottom: 2.5rem;
  padding: 2.5rem;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.08);
}

h2 {
  color: #002060;
  margin-bottom: 1.2rem;
  font-size: 1.6rem;
  position: relative;
  padding-bottom: 0.5rem;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 4px;
  background: #007BFF;
  border-radius: 2px;
}

h3 {
  color: #003399;
  margin: 1.2rem 0 0.8rem;
}

ul, ol {
  margin: 0.8rem 0 1.2rem 1.8rem;
}

.highlight {
  background: #e3f2fd;
  padding: 1.2rem;
  border-left: 5px solid #007BFF;
  margin: 1.5rem 0;
  font-style: italic;
  border-radius: 8px;
}

.btn {
  display: inline-block;
  background: #007BFF;
  color: white;
  padding: 0.8rem 1.8rem;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 600;
  box-shadow: 0 4px 15px rgba(0,123,255,0.3);
  transition: all 0.3s;
  border: none;
  cursor: pointer;
}

.btn:hover {
  background: #0056b3;
  transform: translateY(-2px);
}

footer {
  text-align: center;
  padding: 3rem 2rem;
  background: #002060;
  color: white;
  margin-top: 4rem;
}

footer p {
  margin: 0.5rem 0;
  opacity: 0.9;
}

/* Responsive */
@media (max-width: 768px) {
  nav ul {
    flex-direction: column;
    align-items: center;
    gap: 0.8rem;
  }
  main {
    padding: 0 1rem;
  }
}