/* ============================================
   Header Styles - 页眉样式（统一版本）
   包含所有页眉相关的样式
   ============================================ */

/* ============================================
   基础页眉结构
   ============================================ */
.main-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 2000;
  background: transparent;
  margin-top: 0;
  transition: 
    opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1),
    filter 1s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 页眉隐藏状态：慢慢失焦往上消失效果 */
.main-header.header-hidden {
  opacity: 0;
  filter: blur(12px);
  transform: translateY(-40px);
  pointer-events: none;
}

/* 页眉背景层 */
.main-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  width: auto;
  height: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: 0;
  opacity: 0;
  transition: opacity 0.35s ease;
  z-index: -1;
}

.main-header.sticky::before {
  opacity: 1;
}

/* 页眉容器 */
.header__container {
  max-width: 1920px;
  margin: 0 auto;
  padding: 0 50px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 90px;
  position: relative;
  z-index: 1;
}

/* Logo */
.header-logo {
  display: flex;
  align-items: center;
  z-index: 1;
}

.logo-img {
  height: 50px;
  width: auto;
  transition: filter 0.3s ease;
}

/* 暗背景时 Logo 反色 */
.main-header.dark-bg:not(.sticky) .logo-img {
  filter: brightness(0) invert(1);
}

/* ============================================
   导航菜单
   ============================================ */
.header__nav {
  display: flex;
  align-items: center;
  gap: 0;
  margin-right: 110px;
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.main-header.menu-open .header__nav {
  transform: translateX(-270px);
}

.nav__list,
.nav-menu {
  display: flex;
  align-items: center;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav__item {
  position: relative;
  margin-right: 40px;
}

.nav__item:last-child {
  margin-right: 20px;
}

.nav__link {
  display: inline-block;
  padding: 8px 0;
  font-family: 'Noto Sans SC', 'Source Han Sans CN', 'Source Han Sans', 'Microsoft YaHei', 'SimHei', sans-serif;
  font-size: var(--font-size-nav);
  font-weight: 400;
  color: #000000;
  text-decoration: none;
  transition: color 0.3s ease;
  position: relative;
}

.nav__link:hover {
  color: #000;
}

.nav__item.active .nav__link {
  color: #000;
}

/* 导航菜单文本容器 */
.nav__text {
  position: relative;
  display: inline-block;
  white-space: nowrap;
  text-align: center;
  transform: translateY(-2px);
}

/* 英文文本 - 默认显示 */
.nav__text--en {
  display: inline-block;
  white-space: nowrap;
  transition: opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1), transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  text-transform: capitalize;
  transform: translateY(0);
}

/* 中文文本 - 默认隐藏 */
.nav__text--zh {
  position: absolute;
  left: 50%;
  top: 0;
  transform: translateX(-50%) translateY(8px);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1), transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 悬停时：隐藏英文，显示中文 */
.nav__link:hover .nav__text--en {
  opacity: 0;
  transform: translateY(-8px);
}

.nav__link:hover .nav__text--zh {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* 语言切换为中文时，导航菜单显示中文，悬停切换英文 */
.main-header.lang-zh .nav__text--en {
  opacity: 0;
  transform: translateY(-8px);
  position: relative;
  pointer-events: none;
}

.main-header.lang-zh .nav__text--zh {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
  position: absolute;
  left: 50%;
  top: 0;
  white-space: nowrap;
}

.main-header.lang-zh .nav__link:hover .nav__text--en {
  opacity: 1;
  transform: translateY(0);
}

.main-header.lang-zh .nav__link:hover .nav__text--zh {
  opacity: 0;
  transform: translateX(-50%) translateY(8px);
}

/* 激活状态：默认英文模式下保持显示中文（悬停后的状态） */
.nav__item.active .nav__text--en {
  opacity: 0;
  transform: translateY(-8px);
}

.nav__item.active .nav__text--zh {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* 激活状态悬停：切换回英文 */
.nav__item.active .nav__link:hover .nav__text--en {
  opacity: 1;
  transform: translateY(0);
}

.nav__item.active .nav__link:hover .nav__text--zh {
  opacity: 0;
  transform: translateX(-50%) translateY(8px);
}

/* lang-zh 模式下激活状态：保持显示英文（悬停后的状态） */
.main-header.lang-zh .nav__item.active .nav__text--en {
  opacity: 1;
  transform: translateY(0);
  position: relative;
  pointer-events: none;
}

.main-header.lang-zh .nav__item.active .nav__text--zh {
  opacity: 0;
  transform: translateX(-50%) translateY(8px);
  position: absolute;
  left: 50%;
  top: 0;
  white-space: nowrap;
}

/* lang-zh 模式下激活状态悬停：切换回中文 */
.main-header.lang-zh .nav__item.active .nav__link:hover .nav__text--en {
  opacity: 0;
  transform: translateY(-8px);
}

.main-header.lang-zh .nav__item.active .nav__link:hover .nav__text--zh {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* 暗背景状态 */
.main-header.dark-bg:not(.sticky) .nav__link {
  color: rgba(255, 255, 255, 0.9);
}

.main-header.dark-bg:not(.sticky) .nav__link:hover {
  color: #fff;
}

.main-header.dark-bg:not(.sticky) .nav__item.active .nav__link {
  color: #fff;
}

/* 吸附状态强制使用深色 */
.main-header.sticky .nav__link {
  color: #000000 !important;
}

.main-header.sticky .nav__link:hover {
  color: #000 !important;
}

.main-header.sticky .nav__item.active .nav__link {
  color: #000 !important;
}

/* ============================================
   全屏按钮
   ============================================ */
.nav__item--fullscreen {
  margin-right: 16px;
}

.header-fullscreen-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px;
  background: transparent;
  border: none;
  cursor: pointer;
  color: inherit;
  transition: color 0.3s ease, opacity 0.3s ease;
  opacity: 0.75;
}

.header-fullscreen-toggle:hover {
  opacity: 1;
}

.header-fullscreen-icon {
  display: block;
  flex-shrink: 0;
  transition: color 0.3s ease;
}

.main-header:not(.dark-bg) .header-fullscreen-toggle {
  color: #242424;
}

.main-header:not(.dark-bg) .header-fullscreen-toggle:hover {
  color: #000;
}

.main-header.dark-bg .header-fullscreen-toggle {
  color: rgba(255, 255, 255, 0.9);
}

.main-header.dark-bg .header-fullscreen-toggle:hover {
  color: #fff;
}

.main-header.sticky:not(.dark-bg) .header-fullscreen-toggle {
  color: #000000 !important;
}

.main-header.sticky.dark-bg .header-fullscreen-toggle {
  color: rgba(255, 255, 255, 0.9) !important;
}

/* 退出全屏状态：高亮区分 */
.header-fullscreen-toggle.is-fullscreen {
  opacity: 1;
  background: rgba(0, 0, 0, 0.08);
  border-radius: 8px;
}

.main-header.dark-bg .header-fullscreen-toggle.is-fullscreen {
  background: rgba(255, 255, 255, 0.15);
}

/* Tooltip */
.header-fullscreen-toggle {
  position: relative;
}

.header-fullscreen-toggle::after {
  content: attr(data-tooltip);
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%) translateY(-4px);
  background: rgba(20, 20, 20, 0.88);
  color: #fff;
  font-size: 12px;
  font-weight: 500;
  font-family: 'Noto Sans SC', sans-serif;
  white-space: nowrap;
  padding: 5px 10px;
  border-radius: 6px;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.18s ease, transform 0.18s ease;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 100;
}

.header-fullscreen-toggle:hover::after {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ============================================
   语言切换按钮
   ============================================ */
.nav__item--lang {
  margin-right: 0;
}

.header-lang-toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: flex-start;
  gap: 8px;
  height: auto;
  padding: 8px 0;
  background: transparent;
  border: none;
  cursor: pointer;
  font-size: var(--font-size-nav);
  font-weight: 400;
  font-family: 'Noto Sans SC', 'Source Han Sans CN', 'Source Han Sans', 'Microsoft YaHei', 'SimHei', sans-serif;
  color: inherit;
  transition: color 0.3s ease;
}

.header-lang-icon {
  width: 24px;
  height: 24px;
  transition: color 0.3s ease;
  display: block;
  flex-shrink: 0;
  color: currentColor;
}

.main-header:not(.dark-bg) .header-lang-toggle {
  color: #242424;
}

.main-header:not(.dark-bg) .header-lang-toggle:hover {
  color: #000;
}

.main-header.dark-bg .header-lang-toggle {
  color: rgba(255, 255, 255, 0.9);
}

.main-header.dark-bg .header-lang-toggle:hover {
  color: #fff;
}

.main-header.sticky:not(.dark-bg) .header-lang-toggle {
  color: #000000 !important;
}

.main-header.sticky.dark-bg .header-lang-toggle {
  color: rgba(255, 255, 255, 0.9) !important;
}

.main-header.sticky:not(.dark-bg) .lang__text--en,
.main-header.sticky:not(.dark-bg) .lang__text--zh {
  color: #000000 !important;
}

.main-header.sticky.dark-bg .lang__text--en,
.main-header.sticky.dark-bg .lang__text--zh {
  color: rgba(255, 255, 255, 0.9) !important;
}

.main-header.sticky .header-lang-toggle:hover {
  color: #000000 !important;
}

/* 语言文本容器 - 与菜单项一致的结构 */
.lang__text {
  position: relative;
  display: inline-block;
  white-space: nowrap;
  text-align: center;
  transform: translateY(-1px);
}

/* 英文文本 - 默认隐藏（因为默认菜单是英文，语言切换显示中文） */
.lang__text--en {
  display: inline-block;
  white-space: nowrap;
  transition: opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1), transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  opacity: 0;
  transform: translateY(-8px);
  pointer-events: none;
}

/* 中文文本 - 默认显示（因为默认菜单是英文，语言切换显示中文） */
.lang__text--zh {
  position: absolute;
  left: 50%;
  top: 0;
  transform: translateX(-50%) translateY(0);
  white-space: nowrap;
  opacity: 1;
  pointer-events: none;
  transition: opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1), transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 悬停时切换：显示 English，隐藏中文 */
.header-lang-toggle:hover .lang__text--en {
  opacity: 1;
  transform: translateY(0);
}

.header-lang-toggle:hover .lang__text--zh {
  opacity: 0;
  transform: translateX(-50%) translateY(8px);
}

/* 语言切换为中文时（菜单显示中文），语言切换默认显示 English */
.main-header.lang-zh .lang__text--en {
  opacity: 1;
  transform: translateY(0);
  position: relative;
  pointer-events: none;
}

.main-header.lang-zh .lang__text--zh {
  opacity: 0;
  transform: translateX(-50%) translateY(8px);
  position: absolute;
  left: 50%;
  top: 0;
  white-space: nowrap;
}

/* 中文模式悬停时：显示中文，隐藏 English */
.main-header.lang-zh .header-lang-toggle:hover .lang__text--en {
  opacity: 0;
  transform: translateY(-8px);
}

.main-header.lang-zh .header-lang-toggle:hover .lang__text--zh {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ============================================
   汉堡菜单按钮
   ============================================ */
.hamburger__line {
  width: 20px;
  height: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease, background 0.3s ease;
}

/* 默认状态（亮背景）：深色图标 */
.main-header:not(.dark-bg) .hamburger__line {
  background: #242424;
}

/* 暗背景状态：浅色图标 */
.main-header.dark-bg .hamburger__line {
  background: rgba(255, 255, 255, 0.9);
}

/* ============================================
   菜单容器（A容器）
   ============================================ */
.menu-container {
  position: absolute;
  top: 5px;
  right: 50px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  width: 80px;
  background: transparent;
  border-radius: 10px;
  overflow: hidden;
  transition: 
    width 0.3s cubic-bezier(0.4, 0, 0.2, 1),
    background 0.3s cubic-bezier(0.4, 0, 0.2, 1),
    box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.menu-container.is-open {
  width: 350px;
  background: #ffffff;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
  border-radius: 10px;
}

.main-header.sticky .menu-container.is-open {
  background: transparent;
  box-shadow: none;
  border-radius: 10px;
  transition: 
    width 0.3s cubic-bezier(0.4, 0, 0.2, 1),
    background 0.35s ease,
    box-shadow 0.35s ease;
}

/* 菜单容器顶部 */
.menu-container__top {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  width: 100%;
  height: 80px;
  flex-shrink: 0;
  border-bottom: 1px solid transparent;
  transition: border-bottom 0.35s ease;
}

.menu-container.is-open .menu-container__top {
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.main-header.sticky .menu-container__top {
  border-bottom: 1px solid transparent;
}

/* 图标组 */
.menu-container__icons {
  display: flex;
  align-items: center;
  gap: 0;
  margin-right: auto;
  padding-left: 16px;
}

/* 图标按钮 */
.menu-container__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: transparent;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  color: #000000;
  text-decoration: none;
  flex-shrink: 0;
  opacity: 0;
  transform: scale(0.8);
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.menu-container__icon:hover {
  background: transparent;
}

/* 语言图标桌面端隐藏 */
.menu-container__icon--lang {
  display: none;
}

/* 图标逐个显示动画 */
.menu-container.is-open .menu-container__icon--search {
  opacity: 1;
  transform: scale(1);
  transition-delay: 0.15s;
}

.menu-container.is-open .menu-container__icon:nth-child(3) {
  opacity: 1;
  transform: scale(1);
  transition-delay: 0.22s;
}

.menu-container.is-open .menu-container__icon:nth-child(4) {
  opacity: 1;
  transform: scale(1);
  transition-delay: 0.29s;
}

/* 汉堡按钮 */
.menu-container__hamburger {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  width: 90px;
  height: 90px;
  background: transparent;
  border: none;
  cursor: pointer;
  flex-shrink: 0;
}

.menu-container__hamburger:hover {
  background: transparent;
}

/* 汉堡线颜色 */
.main-header.dark-bg .menu-container:not(.is-open) .hamburger__line {
  background: rgba(255, 255, 255, 0.9);
}

.menu-container.is-open .hamburger__line {
  background: #000000;
}

/* 汉堡变X动画 */
.menu-container.is-open .menu-container__hamburger .hamburger__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-container.is-open .menu-container__hamburger .hamburger__line:nth-child(2) {
  opacity: 0;
}

.menu-container.is-open .menu-container__hamburger .hamburger__line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ============================================
   下拉菜单（B容器）
   ============================================ */
.menu-container__dropdown {
  width: 350px;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  background: transparent;
  border-radius: 0;
  margin-top: 0;
  transition: 
    max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1),
    opacity 0.25s ease,
    background 0.35s ease,
    border-radius 0.35s ease,
    margin-top 0.35s ease;
}

.menu-container.is-open .menu-container__dropdown {
  max-height: 400px;
  opacity: 1;
  transition: 
    max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1) 0.35s,
    opacity 0.25s ease 0.35s,
    background 0.35s ease,
    border-radius 0.35s ease,
    margin-top 0.35s ease;
}

.main-header.sticky .menu-container.is-open .menu-container__dropdown {
  background: #ffffff;
  border-radius: 10px;
  margin-top: 10px;
}

.menu-container__dropdown .dropdown__item,
.menu-container__dropdown .dropdown__text {
  opacity: 1;
}

/* 下拉菜单项 */
.dropdown__item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
  padding: 0 24px;
  text-decoration: none;
  color: #242424;
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  transition: color 0.3s ease, background 0.3s ease;
  position: relative;
}

.dropdown__item:last-child {
  border-bottom: none;
}

.dropdown__item:hover {
  color: #242424;
  background: rgba(0, 0, 0, 0.02);
}

.dropdown__text {
  position: relative;
  display: inline-block;
  white-space: nowrap;
  text-align: left;
  transform: translateY(-2px);
  font-family: 'Noto Sans SC', 'Source Han Sans CN', 'Source Han Sans', 'Microsoft YaHei', 'SimHei', sans-serif;
  font-size: var(--font-size-base);
  font-weight: 400;
  line-height: 1.5;
}

/* 英文和中文文本容器 */
.dropdown__text--en {
  display: inline-block;
  white-space: nowrap;
  transition: opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1), transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  text-transform: capitalize;
  transform: translateY(0);
}

.dropdown__text--zh {
  position: absolute;
  left: 0;
  top: 0;
  transform: translateY(8px);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1), transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.dropdown__item:hover .dropdown__text--en {
  opacity: 0;
  transform: translateY(-8px);
}

.dropdown__item:hover .dropdown__text--zh {
  opacity: 1;
  transform: translateY(0);
}

/* 语言切换为中文时 */
.main-header.lang-zh .dropdown__text--en {
  opacity: 0;
  transform: translateY(-8px);
  position: absolute;
  left: 0;
  top: 0;
}

.main-header.lang-zh .dropdown__text--zh {
  opacity: 1;
  transform: translateY(0);
  position: relative;
}

.main-header.lang-zh .dropdown__item:hover .dropdown__text--en {
  opacity: 1;
  transform: translateY(0);
}

.main-header.lang-zh .dropdown__item:hover .dropdown__text--zh {
  opacity: 0;
  transform: translateY(8px);
}

/* CTA菜单项（加入我们） */
.dropdown__item--cta {
  background: #fff;
  color: #242424;
  height: 100px;
  padding-bottom: 16px;
  position: relative;
}

.dropdown__item--cta:hover {
  background: rgba(0, 0, 0, 0.02);
  color: #000;
}

.header-dropdown-cta-text {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.header-dropdown-cta-email {
  font-family: 'Noto Sans SC', 'Source Han Sans CN', 'Source Han Sans', 'Microsoft YaHei', 'SimHei', sans-serif;
  font-size: var(--font-size-base);
  font-weight: 400;
  line-height: 1.5;
  color: #242424;
}

.header-dropdown-cta-label {
  font-family: 'Noto Sans SC', 'Source Han Sans CN', 'Source Han Sans', 'Microsoft YaHei', 'SimHei', sans-serif;
  font-size: var(--font-size-xs);
  font-weight: 400;
  line-height: 1.5;
  opacity: 0.9;
  color: #242424;
}

.menu-container__dropdown .dropdown__item--cta::after {
  content: '' !important;
  position: absolute !important;
  right: 40px !important;
  top: 28px !important;
  transform: translateX(-5px) !important;
  width: 22px !important;
  height: 22px !important;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='%23000000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12h14'/%3E%3Cpath d='m12 5 7 7-7 7'/%3E%3C/svg%3E") !important;
  background-size: contain !important;
  background-repeat: no-repeat !important;
  opacity: 0;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.menu-container__dropdown .dropdown__item--cta:hover::after {
  opacity: 1 !important;
  transform: translateX(0) !important;
}

/* ============================================
   遮罩层
   ============================================ */
.header-menu-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0);
  z-index: 1000;
  pointer-events: none;
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
  transition: background 0.4s cubic-bezier(0.4, 0, 0.2, 1),
              backdrop-filter 0.4s cubic-bezier(0.4, 0, 0.2, 1),
              -webkit-backdrop-filter 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.header-menu-overlay.is-visible {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  pointer-events: auto;
}

/* ============================================
   移动端汉堡触发器（桌面端隐藏）
   ============================================ */
.mobile-hamburger {
  display: none;
}

/* 桌面端隐藏的元素 */
.menu-container__nav-mobile,
.menu-container__divider,
.menu-container__logo {
  display: none;
}

/* ============================================
   移动端样式 (max-width: 1024px)
   ============================================ */
/* 移动端菜单打开时锁定body滚动 */
body.menu-open-lock {
  overflow: hidden;
  position: fixed;
  width: 100%;
  height: 100%;
}

@media (max-width: 1024px) {
  /* 移动端不需要遮罩 */
  .header-menu-overlay {
    display: none;
  }
  
  /* 隐藏桌面端导航 */
  .header__nav {
    display: none;
  }
  
  /* 移动端header容器高度缩小 */
  .header__container {
    height: 70px;
    padding: 0 20px;
  }
  
  /* 移动端Logo */
  .logo-img {
    height: 42px;
  }
  
  /* 移动端汉堡触发器 */
  .mobile-hamburger {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    background: transparent;
    border: none;
    cursor: pointer;
  }
  
  .main-header.dark-bg .mobile-hamburger .hamburger__line {
    background: rgba(255, 255, 255, 0.9);
  }
  
  .main-header.sticky .mobile-hamburger .hamburger__line {
    background: #000000;
  }
  
  /* A容器 - 移动端全屏展开 */
  .menu-container {
    position: fixed;
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    width: 100% !important;
    height: 100%;
    border-radius: 0 !important;
    background: #fff;
    opacity: 0;
    visibility: hidden;
    overflow: hidden;
    transform: translateY(-100%);
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease, visibility 0.3s ease;
    z-index: 10001;
    box-sizing: border-box;
  }
  
  .menu-container.is-open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    box-shadow: none;
    border-radius: 0 !important;
    overflow-y: auto;
    overflow-x: hidden;
    max-height: 100vh;
    max-height: 100dvh;
    display: flex;
    flex-direction: column;
  }

  /* 菜单项入场动画 */
  .menu-container__nav-mobile .dropdown__item,
  .menu-container__secondary .dropdown__item {
    opacity: 0;
    transform: translateY(12px);
    transition: opacity 0.3s ease, transform 0.3s ease;
  }
  .menu-container.is-open .menu-container__nav-mobile .dropdown__item,
  .menu-container.is-open .menu-container__secondary .dropdown__item {
    opacity: 1;
    transform: translateY(0);
  }
  .menu-container.is-open .menu-container__nav-mobile .dropdown__item:nth-child(1) { transition-delay: 0.15s; }
  .menu-container.is-open .menu-container__nav-mobile .dropdown__item:nth-child(2) { transition-delay: 0.2s; }
  .menu-container.is-open .menu-container__nav-mobile .dropdown__item:nth-child(3) { transition-delay: 0.25s; }
  .menu-container.is-open .menu-container__nav-mobile .dropdown__item:nth-child(4) { transition-delay: 0.3s; }
  .menu-container.is-open .menu-container__nav-mobile .dropdown__item:nth-child(5) { transition-delay: 0.35s; }
  .menu-container.is-open .menu-container__nav-mobile .dropdown__item:nth-child(6) { transition-delay: 0.4s; }
  .menu-container.is-open .menu-container__secondary .dropdown__item:nth-child(1) { transition-delay: 0.45s; }
  .menu-container.is-open .menu-container__secondary .dropdown__item:nth-child(2) { transition-delay: 0.5s; }
  .menu-container.is-open .menu-container__secondary .dropdown__item:nth-child(3) { transition-delay: 0.55s; }
  .menu-container.is-open .menu-container__secondary .dropdown__item:nth-child(4) { transition-delay: 0.6s; }
  
  /* 顶部区域 */
  .menu-container__top {
    height: 70px;
    min-height: 70px;
    padding: 0 20px;
    justify-content: space-between;
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    flex-shrink: 0;
    box-sizing: border-box;
    width: 100%;
  }
  
  .main-header.sticky .menu-container__top {
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  }
  
  /* 移动端专用元素显示 */
  .menu-container__logo {
    display: flex;
    align-items: center;
    flex-shrink: 0;
    margin-right: auto;
  }
  
  .menu-container__logo img {
    height: 42px;
    width: auto;
  }
  
  /* 图标组 */
  .menu-container__icons {
    margin-left: 16px;
    margin-right: 12px;
    padding-left: 0;
    gap: 2px;
    flex-shrink: 0;
  }
  
  .menu-container__icon {
    opacity: 1 !important;
    transform: scale(1) !important;
    transition-delay: 0s !important;
    width: 40px;
    height: 40px;
  }
  
  .menu-container__icon svg {
    width: 20px;
    height: 20px;
  }
  
  /* 汉堡按钮 */
  .menu-container__hamburger {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
  }
  
  .menu-container .hamburger__line {
    background: #000000 !important;
  }
  
  /* B容器 - 全屏菜单内容区 */
  .menu-container__dropdown {
    width: 100%;
    max-width: 100%;
    max-height: none !important;
    opacity: 1 !important;
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    box-sizing: border-box;
  }
  
  .menu-container.is-open .menu-container__dropdown {
    max-height: none;
    transition: none;
  }
  
  /* 移动端导航项 - 统一格式 */
  .menu-container__dropdown .dropdown__item {
    height: auto;
    min-height: 56px;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    border-bottom: none;
    box-sizing: border-box;
    width: 100%;
    max-width: 100%;
  }
  
  .menu-container__dropdown .dropdown__text {
    font-size: 18px;
    font-weight: 400;
    color: #1b1b1b;
  }
  
  .menu-container__dropdown .dropdown__text--en {
    text-transform: none;
    letter-spacing: -0.01em;
  }
  
  /* 主导航区域 */
  .menu-container__nav-mobile {
    display: flex;
    flex-direction: column;
    padding: 16px 0 8px;
  }
  
  .menu-container__nav-mobile .dropdown__item {
    border-bottom: none;
  }
  
  /* 分隔线 */
  .menu-container__divider {
    display: block;
    height: 1px;
    background: rgba(0, 0, 0, 0.06);
    margin: 8px 24px;
    border: none;
    width: auto;
    flex-shrink: 0;
  }
  
  /* 次级菜单区域 - 紧跟主菜单 */
  .menu-container__secondary {
    padding: 4px 0 0;
  }
  
  .menu-container__secondary .dropdown__item {
    min-height: 48px;
    padding: 12px 24px;
  }
  
  .menu-container__secondary .dropdown__text {
    font-size: 16px;
    font-weight: 400;
    color: #999;
  }
  
  /* 吸附状态样式 */
  .main-header.sticky .menu-container.is-open {
    background: #fff;
  }
  
  .main-header.sticky .menu-container.is-open .menu-container__dropdown {
    background: transparent;
    border-radius: 0;
    margin-top: 0;
  }
  
  /* 语言图标 - 移动端显示 */
  .menu-container__icon--lang {
    display: flex !important;
    opacity: 1 !important;
    transform: scale(1) !important;
  }
  
  .menu-container__icon--lang svg,
  .menu-container__icon--lang svg path {
    color: #000000 !important;
    fill: #000000 !important;
  }
  
  /* 桌面端导航中的语言切换和全屏按钮在移动端隐藏 */
  .nav__item--lang,
  .nav__item--fullscreen {
    display: none !important;
  }
  
  /* CTA菜单项 */
  .menu-container__dropdown .dropdown__item--cta {
    margin-top: auto;
    margin-bottom: 0;
    padding: 16px 24px;
    padding-bottom: calc(24px + env(safe-area-inset-bottom, 0px));
    min-height: auto;
  }
  
  .menu-container__dropdown .dropdown__item--cta::after {
    right: 24px;
    top: calc(50% - 8px);
  }
  
  .menu-container__dropdown .dropdown__item--cta .header-dropdown-cta-email {
    font-size: 16px;
  }
  
  .menu-container__dropdown .dropdown__item--cta .header-dropdown-cta-label {
    font-size: 12px;
  }
}

/* ============================================
   小屏幕适配 (max-width: 480px)
   ============================================ */
@media (max-width: 480px) {
  .header__container {
    padding: 0 16px;
    height: 60px;
  }
  
  /* 小屏幕Logo */
  .logo-img {
    height: 35px;
  }
  
  .menu-container__top {
    height: 60px;
    min-height: 60px;
    padding: 0 16px;
  }
  
  .menu-container__logo img {
    height: 35px;
  }
  
  .menu-container__icons {
    margin-left: 12px;
    margin-right: 8px;
    gap: 0;
  }
  
  .menu-container__icon {
    width: 36px;
    height: 36px;
  }
  
  .menu-container__icon svg {
    width: 18px;
    height: 18px;
  }
  
  .menu-container__dropdown .dropdown__item {
    min-height: 50px;
    padding: 14px 20px;
  }
  
  .menu-container__dropdown .dropdown__text {
    font-size: 16px;
  }
  
  .menu-container__nav-mobile {
    padding: 12px 0 6px;
  }
  
  .menu-container__divider {
    margin: 6px 20px;
  }
  
  .menu-container__secondary .dropdown__item {
    min-height: 46px;
    padding: 12px 20px;
  }
  
  .menu-container__secondary .dropdown__text {
    font-size: 14px;
  }
  
  .menu-container__dropdown .dropdown__item--cta {
    padding: 14px 20px;
    padding-bottom: calc(20px + env(safe-area-inset-bottom, 0px));
  }
  
  .menu-container__dropdown .dropdown__item--cta .header-dropdown-cta-email {
    font-size: 14px;
  }
  
  .menu-container__hamburger {
    width: 40px;
    height: 40px;
  }
  
  .mobile-hamburger {
    width: 40px;
    height: 40px;
  }
}

/* ============================================
   大屏幕适配 (max-width: 1440px)
   ============================================ */
@media (min-width: 1201px) and (max-width: 1440px) {
  .header__container {
    padding: 0 40px;
  }
  
  .nav__item {
    margin-right: 36px;
  }
  
  .nav__item:last-child {
    margin-right: 18px;
  }
}

/* ============================================
   中等屏幕适配 (1025px - 1200px)
   ============================================ */
@media (min-width: 1025px) and (max-width: 1200px) {
  .header__container {
    padding: 0 30px;
  }
  
  .nav__item {
    margin-right: 28px;
  }
  
  .nav__item:last-child {
    margin-right: 14px;
  }
  
  .nav__link {
    font-size: 16px;
  }
}