.topbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: #fff;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.12);
  user-select: none;
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0;
}

.logo {
  display: block;
  flex-shrink: 0;
  height: 36px;
  width: auto;
  aspect-ratio: 682 / 74;
  margin: 23px 0;
}

.nav {
  display: flex;
  align-self: stretch;
  align-items: stretch;
  color: var(--text-dark);
}

.menu-list {
  list-style: none;
}

.menu-level-1 {
  display: flex;
  height: 100%;
  align-items: stretch;
}

.menu-level-1 > .menu-item + .menu-item {
  margin-left: 75px;
}

.menu-level-1 > .menu-item {
  display: flex;
  align-items: center;
}

.menu-item {
  position: relative;
}

.menu-link,
.menu-trigger {
  position: relative;
  padding: 0;
  display: inline-flex;
  align-items: center;
  font-family: "Noto Sans SC", sans-serif;
  font-weight: 500;
  font-size: 16px;
  color: #0C4CD1;
  line-height: 1;
  white-space: nowrap;
  transition: color 0.25s ease;
}

/* top-level menu items: height + vertical margins */
.menu-level-1 > .menu-item > .menu-link,
.menu-level-1 > .menu-item > .menu-trigger {
  height: 36px;
  margin: 23px 0;
}

/* hover underline */
.menu-level-1 > .menu-item > .menu-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: #0C4CD1;
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 0.3s ease;
}

.menu-level-1 > .menu-item:hover > .menu-link::after {
  transform: scaleX(1);
}

.menu-trigger {
  border: none;
  background: none;
  cursor: pointer;
}

/* 顶栏菜单项隐藏下箭头 */
.menu-level-1 > .menu-item.has-children > .menu-trigger::after {
  display: none;
}

.menu-item.has-children > .menu-trigger::after {
  content: "";
  width: 6px;
  height: 6px;
  margin-left: 6px;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg) translateY(-1px);
  transform-origin: center;
  transition: transform 0.2s ease;
}

.menu-item.has-children.is-open > .menu-trigger::after {
  transform: rotate(-135deg) translateY(-1px);
}

.submenu .menu-item.has-children > .menu-trigger::after {
  transform: translateX(8px) rotate(-45deg);
}

.menu-link:hover,
.menu-trigger:hover {
  color: #0C4CD1;
}

.submenu {
  position: absolute;
  top: calc(100% + 10px);
  left: -30px;
  background: #fff;
  color: #1f2933;
  border: none;
  border-radius: 6px;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.1);
  padding: 0;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.22s ease, transform 0.22s ease, visibility 0.22s ease;
  z-index: 1200;
}

.menu-level-1 > .menu-item.has-children > .submenu {
  top: calc(100% - 1px);
}

.submenu .menu-link,
.submenu .menu-trigger {
  width: 100%;
  padding: 20px 30px;
  font-size: 16px;
  color: #1f2933;
  justify-content: space-between;
}

.submenu .menu-link:hover,
.submenu .menu-trigger:hover {
  color: #0C4CD1;
  background: #f1f5f9;
}

.submenu > .menu-item:first-child > .menu-link:hover,
.submenu > .menu-item:first-child > .menu-trigger:hover {
  border-radius: 6px 6px 0 0;
}

.submenu > .menu-item:last-child > .menu-link:hover,
.submenu > .menu-item:last-child > .menu-trigger:hover {
  border-radius: 0 0 6px 6px;
}

.menu-item.has-children:hover > .submenu {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.submenu .submenu {
  top: -1px;
  left: 100%;
}

.menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 6px;
  border-radius: 6px;
  color: var(--text-dark);
}

.menu-line {
  width: 22px;
  height: 2px;
  background: currentColor;
  border-radius: 999px;
}

.menu-toggle .menu-line {
  background-color: #0C4CD1;
}

.menu-mask {
  display: none;
  background-color: rgba(0, 0, 0, 0.35);
}