/* ========================================
   导航栏样式
   ======================================== */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: rgba(255, 255, 255, 0.98);
  border-bottom: 1px solid rgba(15, 23, 42, 0.06);
  box-shadow: 0 8px 25px rgba(15, 23, 42, 0.08);
  z-index: 1000;
  transition: background var(--transition-base), transform var(--transition-base);
}

body {
  padding-top: 80px;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: 0 12px 30px rgba(15, 23, 42, 0.12);
}

.navbar-container {
  max-width: var(--layout-wide-width);
  margin: 0 auto;
  height: 100%;
  padding: 0 var(--spacing-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-xl);
}

.navbar-logo {
  font-size: 1.4rem;
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
  letter-spacing: 0.08em;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  white-space: nowrap;
}

.navbar-menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
  list-style: none;
  flex-wrap: nowrap;
  margin: 0;
  padding: 0;
  height: 100%;
}

.navbar-cta-strip {
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-color);
}

.navbar-cta-inner {
  max-width: var(--layout-wide-width);
  margin: 0 auto;
  padding: var(--spacing-sm) var(--spacing-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-md);
}

.navbar-cta-btn {
  padding: 0.55rem 1.4rem;
  font-size: var(--font-size-sm);
}

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

.navbar-link {
  font-size: 0.95rem;
  font-weight: var(--font-weight-medium);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) 0;
  border-bottom: 2px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
  white-space: nowrap;
  height: 100%;
}

.navbar-link:hover,
.navbar-link.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.dropdown-arrow {
  width: 7px;
  height: 7px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform var(--transition-fast);
}

.navbar-item:hover .dropdown-arrow,
.navbar-item.open .dropdown-arrow {
  transform: rotate(225deg);
}

.navbar-submenu {
  position: absolute;
  top: calc(100% + 12px);
  left: 0;
  min-width: 240px;
  list-style: none;
  padding: var(--spacing-md);
  border-radius: var(--radius-xl);
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: opacity var(--transition-base), transform var(--transition-base);
  pointer-events: none;
}

.navbar-item:hover > .navbar-submenu,
.navbar-item.open > .navbar-submenu,
.navbar-item:focus-within > .navbar-submenu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.navbar-submenu-link {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

.navbar-submenu-link:hover,
.navbar-submenu-link.active {
  background: var(--bg-tertiary);
  color: var(--color-primary);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: transparent;
  border: none;
  cursor: pointer;
}

.mobile-menu-btn span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.mobile-menu-btn.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 1080px) {
  .navbar-menu {
    gap: var(--spacing-lg);
  }
}

@media (max-width: 992px) {
  .mobile-menu-btn {
    display: inline-flex;
  }

  .navbar-menu {
    position: absolute;
    top: 80px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    background: var(--bg-primary);
    max-height: 0;
    overflow: hidden;
    border-bottom: 1px solid rgba(15, 23, 42, 0.08);
    transition: max-height var(--transition-base);
    padding: 0 var(--spacing-xl);
  }

  .navbar-menu.active {
    max-height: 700px;
    padding-bottom: var(--spacing-xl);
  }

  .navbar-item {
    width: 100%;
  }

  .navbar-submenu {
    position: static;
    transform: none;
    opacity: 1;
    visibility: visible;
    box-shadow: none;
    border: none;
    padding: var(--spacing-sm) 0 var(--spacing-md);
    display: none;
  }

  .navbar-item > .navbar-link {
    justify-content: space-between;
    width: 100%;
  }

  .navbar-item.open > .navbar-submenu {
    display: block;
  }
}

@media (max-width: 640px) {
  .navbar-cta-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .navbar-cta-btn {
    width: 100%;
    text-align: center;
  }
}