.nav-mobile { display: none; }
.nav-desktop { display: flex; }
.nav-desktop .nav-item { position: relative; }
.nav-desktop .dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--white);
  min-width: 200px;
  box-shadow: var(--shadow);
  border-radius: 4px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: var(--transition);
  z-index: 100;
}
.nav-desktop .nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
@media (max-width: 992px) {
  .nav-desktop { display: none !important; }
  .nav-mobile { display: block !important; }
  .nav-mobile-toggle {
    list-style: none;
    cursor: pointer;
    width: 44px;
    height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    color: var(--yale-blue);
  }
  .nav-mobile-toggle::-webkit-details-marker { display: none; }
  .nav-mobile-panel {
    position: absolute;
    top: 78px;
    right: 20px;
    width: min(360px, calc(100vw - 40px));
    background: var(--white);
    box-shadow: var(--shadow);
    border-radius: 10px;
    padding: 10px 0;
    z-index: 1200;
  }

  .nav-mobile-link {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 18px;
    min-height: 44px;
    font-weight: 600;
  }

  .nav-mobile-dd summary {
    list-style: none;
    cursor: pointer;
  }
  .nav-mobile-dd summary::-webkit-details-marker { display: none; }

  .chev { font-size: .9rem; opacity: .7; }

  .nav-mobile-sub {
    background: var(--light-gray);
    padding: 6px 0;
  }

  .nav-mobile-sub a {
    display: block;
    padding: 12px 18px;
    min-height: 44px;
  }

  .nav-mobile-go {
    color: var(--yale-blue);
    font-weight: 700;
  }
}
@media (min-width: 993px) {
  /* 电脑端：隐藏移动端 details 菜单（包含汉堡） */
  .nav-mobile { 
    display: none !important; 
  }

  /* 电脑端：显示桌面菜单 */
  .nav-desktop {
    display: flex !important;
  }

  /* 如果你原先的 .hamburger 被全局显示了，强制电脑端隐藏它 */
  .hamburger {
    display: none !important;
  }

  /* 防止某些 reset 把 summary 变成可见控件 */
  .nav-mobile summary {
    display: none !important;
  }
}