/* ============================================
   天鸿智算 - 导航栏样式
   ============================================ */

/* 头部导航 */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-gray);
  z-index: 1000;
  transition: all var(--transition-normal);
}

.header.scrolled {
  box-shadow: var(--shadow-md);
  background: rgba(255, 255, 255, 0.98);
}

/* 头部容器 */
.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.logo:hover {
  opacity: 0.8;
}

.logo-img {
  width: 36px;
  height: 36px;
}

.logo-text {
  background: linear-gradient(135deg, #dc2626 0%, #ef4444 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* 主导航 */
.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  height: 100%;
}

.nav-item {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  padding: var(--space-sm) var(--space-md);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-primary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--text-red);
  background: var(--bg-red-50);
}

.nav-link.active {
  color: var(--text-red);
  background: var(--bg-red-50);
}

.nav-link .badge {
  margin-left: 0.25rem;
}

.nav-link .arrow {
  width: 16px;
  height: 16px;
  transition: transform var(--transition-fast);
}

.nav-item:hover .nav-link .arrow {
  transform: rotate(180deg);
}

/* 下拉菜单 */
.dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  transform: translateY(10px);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  padding-top: var(--space-sm);
  z-index: 1001;
}

.nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-content {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl), 0 0 0 1px rgba(0, 0, 0, 0.05);
  overflow: hidden;
  min-width: 180px;
}

/* 下拉菜单面板 */
.dropdown-panel {
  width: auto;
  padding: 20px;
  display: block;
  box-sizing: border-box;
  background: var(--bg-white);
}

.menu-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 30px;
  width: 100%;
}

.menu-column {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 0;
}

.menu-column-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-gray);
  white-space: nowrap;
}

.menu-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.menu-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 0;
  font-size: 14px;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  cursor: pointer;
  white-space: nowrap;
}

.menu-item:hover {
  color: var(--text-red);
}

.menu-item-text {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.menu-item-arrow {
  font-size: 0.75rem;
  opacity: 0;
  transform: translateX(-5px);
  transition: all var(--transition-fast);
}

.menu-item:hover .menu-item-arrow {
  opacity: 1;
  transform: translateX(0);
}

/* 产品下拉 */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  width: 100%;
}

.product-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 12px;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
}

.product-item:hover {
  background: var(--bg-red-50);
}

.product-icon {
  width: 48px;
  height: 48px;
  background: var(--gradient-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-white);
  font-size: 1.25rem;
  flex-shrink: 0;
}

.product-info h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.product-info p {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.product-image {
  width: 200px;
  height: 120px;
  background: var(--bg-gray-100);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-tertiary);
  font-size: 0.75rem;
}

/* 右侧操作区 */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.btn-login {
  padding: var(--space-sm) var(--space-md);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-red);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  text-decoration: none;
  cursor: pointer;
}

.btn-login:hover {
  background: var(--bg-red-50);
}

.btn-register {
  padding: var(--space-sm) var(--space-md);
  background: var(--gradient-primary);
  color: var(--text-white);
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  text-decoration: none;
  cursor: pointer;
  border: none;
}

.btn-register:hover {
  opacity: 0.9;
  box-shadow: var(--shadow-red);
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  margin-right: -8px;
}

.mobile-menu-btn span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 1px;
  transition: all var(--transition-fast);
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(8px, 8px);
}

.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* 移动端导航 */
.mobile-nav {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-white);
  padding: var(--space-lg);
  overflow-y: auto;
  z-index: 999;
}

.mobile-nav.active {
  display: block;
}

.mobile-nav-item {
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--border-gray);
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
  text-decoration: none;
  cursor: pointer;
  padding: var(--space-sm) 0;
}

.mobile-nav-link:hover {
  color: var(--text-red);
}

.mobile-nav-link .arrow {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-fast);
}

.mobile-nav-item.active .mobile-nav-link .arrow {
  transform: rotate(180deg);
}

.mobile-submenu {
  display: none;
  flex-direction: column;
  gap: var(--space-sm);
  padding-left: var(--space-lg);
  margin-top: var(--space-md);
}

.mobile-submenu.active {
  display: flex;
}

.mobile-submenu-link {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  text-decoration: none;
  padding: var(--space-sm) 0;
  border-radius: var(--radius-md);
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

.mobile-submenu-link:hover {
  background: var(--bg-red-50);
  color: var(--text-red);
}

/* 响应式 */
@media (max-width: 1024px) {
  .main-nav {
    display: none;
  }
  
  .header-actions {
    display: none;
  }
  
  .mobile-menu-btn {
    display: flex;
  }
}

@media (max-width: 640px) {
  .header-container {
    padding: 0 var(--space-md);
  }
  
  .logo-img {
    width: 32px;
    height: 32px;
  }
}