priority-plus.css

/**
 * Wraps both the visible and cloned nav so we can hide the clone with
 * absolute positioning.
 */
.p-plus-container {
  position: relative;
}

/**
 * Applied to the navigation wrappers. Flexbox is used so the items 'overflow'
 * and also expand to fill additional space.
 */
.p-plus {
  display: flex;
  position: relative;
  z-index: 0;
}

/**
 * Applied only to the invisible 'clone' copy, which we hide.
 */
.p-plus--clone {
  position: absolute;
  top: 0;
  left: 0;
  /* Provides a slight buffer to prevent overflow issues with flex parents. */
  width: calc(100% - 5px);
  pointer-events: none;
  visibility: hidden;
}

/**
 * Ensure we don't cause on-page visible overflow.
 */
.p-plus--clone,
.p-plus--clone .p-plus__primary-wrapper {
  overflow: hidden;
}

/**
 * 'Active' styles for the overflow nav.
 */
.p-plus--is-showing-overflow .p-plus__overflow {
  display: block;
}

/**
 * Hides the toggle button when all the nav items are visible.
 */
.p-plus:not(.p-plus--is-showing-toggle) .p-plus__toggle-btn {
  display: none;
}

.p-plus--is-hiding-primary .p-plus__toggle-btn {
  flex-grow: 1;
}

/**
 * Hides the primary navigation container when all items are in the overflow.
 */
.p-plus--is-hiding-primary .p-plus__primary-wrapper {
  display: none;
}

.p-plus__primary-wrapper {
  display: flex;
  flex-grow: 1;
}

.p-plus__primary {
  display: flex;
  flex: 1 0 auto;
  list-style: none;
  padding: 0;
  margin: 0;
}

.p-plus__primary > li {
  flex: 1 0 auto;
}

/**
 * The overflow 'dropdown' navigation.
 */
.p-plus__overflow {
  display: none;
  position: absolute;
  top: 100%;
  right: 0;
}

.p-plus__toggle-btn {
  flex-shrink: 0;
}