/* ========== 导航栏 ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 48px;
  background: transparent;
  transition: all 0.3s ease;
}

.site-header.scrolled {
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header-brand {
  display: flex;
  align-items: center;
}

.brand-name {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: #ffffff;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.brand-logo {
  font-size: 24px;
  color: #8052ff;
}

.brand-name__en {
  font-weight: 700;
}

.brand-name__sep {
  color: #9a9a9a;
  font-weight: 300;
}

.brand-name__cn {
  font-weight: 400;
  color: #bdbdbd;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  color: #bdbdbd;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.35px;
  transition: color 0.3s ease;
}

.nav-link:hover {
  color: #ffffff;
}

.nav-link.active {
  color: #ffffff;
}

.nav-cta {
  background: #8052ff;
  color: #ffffff;
  padding: 10px 20px;
  border-radius: 20px;
  font-weight: 600;
  transition: all 0.3s ease;
}

.nav-cta:hover {
  background: #9a7aff;
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(128, 82, 255, 0.4);
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
  .site-header {
    padding: 20px 24px;
  }
  
  .header-nav {
    gap: 20px;
  }
  
  .nav-link {
    font-size: 13px;
  }
}

@media (max-width: 768px) {
  .site-header {
    padding: 16px 18px;
  }
  
  .brand-name__cn {
    display: none;
  }
  
  .header-nav {
    gap: 12px;
  }
  
  .nav-link {
    font-size: 12px;
  }
  
  .nav-cta {
    padding: 8px 16px;
    font-size: 12px;
  }
}