/* ===== Header & Navigation ===== */
header {
  background: linear-gradient(90deg, #0d1b2a, #1b263b, #415a77);
  color: #fff;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

header .logo {
  font-size: 1.5rem;
  font-weight: bold;
  letter-spacing: 1px;
}

header .sub {
  font-weight: normal;
  font-size: 1rem;
  opacity: 0.8;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.nav-links li a {
  color: #fff;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s, border-bottom 0.3s;
  padding-bottom: 4px;
}

.nav-links li a:hover {
  color: #ffcc70;
  border-bottom: 2px solid #ffcc70;
}

.nav-links li a.active {
  color: #ffcc70;
  border-bottom: 2px solid #ffcc70;
}

/* ===== Footer ===== */
footer {
  background: #0d1b2a;
  color: #ddd;
  text-align: center;
  padding: 1.5rem;
  margin-top: 3rem;
  font-size: 0.9rem;
  border-top: 2px solid #1b263b;
}

footer p {
  margin: 0;
  opacity: 0.8;
}