/* ===================================
   Header 头部样式
   =================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background-color: var(--background-white);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  z-index: 1000;
  transition: all 0.3s ease;
}

.header.scrolled {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

/* 首页特殊样式：顶部透明黑底白字 */
.header.home-transparent {
  background-color: rgba(0, 0, 0, 0.5);
  box-shadow: none;
}
.header.home-transparent .header-logo img {
  filter: brightness(1);
}
.header.home-transparent:hover .header-logo img {
  filter: brightness(0);
}
.header.home-transparent .header-logo,
.header.home-transparent .nav-link {
  color: #fff;
}

.header.home-transparent .nav-link:hover,
.header.home-transparent .nav-link.active {
  color: var(--primary-light);
}

.header.home-transparent .mobile-menu-btn span {
  background-color: #fff;
}

.header.home-transparent:hover {
  background-color: var(--background-white);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.header.home-transparent:hover .header-logo,
.header.home-transparent:hover .nav-link {
  color: var(--text-primary);
}

.header.home-transparent:hover .nav-link:hover,
.header.home-transparent:hover .nav-link.active {
  color: var(--primary-color);
}

.header.home-transparent:hover .mobile-menu-btn span {
  background-color: var(--text-primary);
}



.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

/* Logo */
.header-logo {
  display: flex;
  align-items: center;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
}

.header-logo img {
  height: 40px;
  margin-right: var(--spacing-sm);
  filter: brightness(0);
}

/* 导航 */
.header-nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.nav-list {
  display: flex;
  gap: var(--spacing-md);
}

.nav-link {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
  padding: var(--spacing-xs) 0;
  position: relative;
  transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-color);
  text-shadow: 0 0 0.65px currentColor;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* 下拉子菜单样式 */
.nav-item {
  position: relative;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  background-color: var(--background-white);
  min-width: 140px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  padding: 8px 0;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 1001;
  text-align: center;
}

.nav-item:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.dropdown-menu li {
  list-style: none;
  width: 100%;
}

.dropdown-menu a {
  display: block;
  padding: 10px 20px;
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.dropdown-menu a:hover {
  background-color: var(--background-light);
  color: var(--primary-color);
}

.header.home-transparent .dropdown-menu {
  background-color: rgba(255, 255, 255, 0.95);
}

.header.home-transparent .dropdown-menu a {
  color: var(--text-primary);
}

.header.home-transparent .dropdown-menu a:hover {
  background-color: rgba(0, 0, 0, 0.05);
  color: var(--primary-color);
}

/* 登录/注册按钮 & 语言切换 */
.header-actions {
  display: flex;
  align-items: center;
  margin-left: 20px;
}

.lang-switch {
  position: relative;
  margin-right: 15px;
  cursor: pointer;
  color: var(--text-primary);
  font-weight: 500;
  font-size: 0.95rem;
}

.lang-switch .current-lang::after {
  content: '▼';
  font-size: 0.6rem;
  margin-left: 4px;
  vertical-align: middle;
}

.header.home-transparent .lang-switch {
  color: #fff;
}

.header.home-transparent:hover .lang-switch {
  color: var(--text-primary);
}

.login-btn {
  display: inline-block;
  padding: 6px 16px;
  font-size: 14px;
  font-weight: 500;
  color: var(--primary-color);
  background-color: transparent;
  border: 1px solid var(--primary-color);
  border-radius: 4px;
  text-decoration: none;
  transition: all 0.3s ease;
  cursor: pointer;
}

.login-btn:hover {
  background-color: var(--primary-color);
  color: #fff;
}

.header.home-transparent .login-btn {
  color: #fff;
  border-color: #fff;
}

.header.home-transparent .login-btn:hover {
  background-color: #fff;
  color: var(--primary-color);
}

.header.home-transparent:hover .login-btn {
  color: var(--primary-color);
  border-color: var(--primary-color);
}

.header.home-transparent:hover .login-btn:hover {
  background-color: var(--primary-color);
  color: #fff;
}

/* CTA 按钮 */
.header-cta {
  margin-left: var(--spacing-md);
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  padding: var(--spacing-xs);
  background: transparent;
  border: none;
  cursor: pointer;
}

.mobile-menu-btn span {
  display: block;
  width: 25px;
  height: 3px;
  background-color: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s ease;
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(6px, 6px);
}

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

.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

/* 移动端菜单 */
.mobile-nav {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 100%;
  background-color: var(--background-white);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  padding: 0;
  z-index: 999;
  max-height: 0;
  overflow-y: auto;
  opacity: 0;
  transition: all 0.3s ease;
}

.mobile-nav.active {
  max-height: calc(100vh - var(--header-height));
  opacity: 1;
}

.mobile-nav .nav-list {
  flex-direction: column;
  gap: 0;
  padding: 0;
  margin: 0;
  list-style: none;
}

.mobile-nav .nav-item {
  width: 100%;
}

.mobile-nav .nav-list > .nav-item > .nav-link {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px var(--spacing-lg);
  font-size: 1.0625rem;
  border-bottom: 1px solid #f0f0f0;
  color: var(--text-primary);
  font-weight: 500;
}

.mobile-nav .nav-link.active {
  color: var(--primary-color);
  background-color: rgba(var(--primary-color-rgb, 0, 102, 204), 0.05);
}

.mobile-nav .nav-item:last-child .nav-link {
  border-bottom: none;
}

.mobile-nav .dropdown-toggle {
  display: inline-block;
  width: 30px;
  height: 30px;
  line-height: 30px;
  text-align: center;
  transition: transform 0.3s ease;
  font-size: 12px;
  color: var(--text-secondary);
}

.mobile-nav .nav-item.open > .nav-link .dropdown-toggle {
  transform: rotate(180deg);
}

.mobile-nav .nav-list > .nav-item > .dropdown-menu {
  position: static;
  transform: none;
  box-shadow: none;
  opacity: 1;
  visibility: visible;
  background-color: #f8f9fa;
  min-width: 100%;
  padding: 0;
  margin: 0;
  border-radius: 0;
  text-align: left;
  display: none;
}

.mobile-nav .nav-list > .nav-item.open > .dropdown-menu {
  display: block;
}

.mobile-nav .nav-list > .nav-item > .dropdown-menu a {
  padding: 12px var(--spacing-lg) 12px 32px;
  border-bottom: 1px solid #f0f0f0;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.mobile-nav .nav-list > .nav-item > .dropdown-menu a:last-child {
  border-bottom: none;
}

.mobile-nav .nav-list > .nav-item > .dropdown-menu a.active {
  color: var(--primary-color);
  font-weight: 500;
}

/* 响应式 */
@media (max-width: 1024px) {
  .header-nav {
    display: none;
  }
  
  .header-actions {
    margin-left: auto;
    margin-right: var(--spacing-md);
  }

  .mobile-menu-btn {
    display: flex;
  }
  
  .mobile-nav {
    display: block;
  }
}

@media (max-width: 576px) {
  .header-actions {
    display: none;
  }

  .mobile-nav {
    padding-bottom: var(--spacing-xl);
  }
  
  .mobile-nav-actions {
    display: flex;
    flex-direction: column;
    padding: var(--spacing-md) var(--spacing-lg);
    gap: var(--spacing-md);
    border-top: 1px solid #f0f0f0;
    margin-top: var(--spacing-sm);
  }
  
  .mobile-nav-actions .lang-switch {
    margin-right: 0;
    padding: var(--spacing-sm) 0;
  }
  
  .mobile-nav-actions .dropdown-menu {
    position: static;
    transform: none;
    box-shadow: none;
    opacity: 1;
    visibility: visible;
    background: transparent;
    padding: 0;
    margin-top: var(--spacing-sm);
    text-align: left;
    display: none;
    min-width: auto;
  }

  .mobile-nav-actions .lang-switch.active .dropdown-menu {
    display: block !important;
    transform: translate(0);
  }

  .mobile-nav-actions .dropdown-menu li {
    width: 100%;
  }

  .mobile-nav-actions .dropdown-menu a {
    padding: 8px 16px;
    color: var(--text-secondary) !important;
    display: block;
    width: 100%;
  }
  
  .mobile-nav-actions .login-btn {
    text-align: center;
    padding: 10px;
  }
 
}