/* 导航栏样式 */
.navbar {
  background: #1e40af;
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav-container {
  max-width: 1000px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
}
.nav-logo {
  color: white;
  font-size: 1.5rem;
  font-weight: bold;
  text-decoration: none;
}
.nav-menu {
  display: flex;
  list-style: none;
  gap: 2rem;
}
.nav-link {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: opacity 0.2s;
}
.nav-link:hover {
  opacity: 0.8;
}
.hamburger {
  display: none;
  cursor: pointer;
}
.bar {
  display: block;
  width: 25px;
  height: 3px;
  margin: 5px auto;
  background: white;
  transition: all 0.3s ease;
}

/* 响应式适配（手机端） */
@media (max-width: 768px) {
  .hamburger {
    display: block;
  }
  .nav-menu {
    position: fixed;
    left: -100%;
    top: 70px;
    flex-direction: column;
    background: #1e40af;
    width: 100%;
    text-align: center;
    transition: 0.3s;
    padding: 1rem 0;
  }
  .nav-menu.active {
    left: 0;
  }
  .nav-link {
    padding: 1rem 0;
    display: block;
  }
  h1 {
    font-size: 2rem;
  }
  .container {
    padding: 1rem;
  }
}