/* Shared Bootstrap 3 book header. Only #navbar is affected.
 * Loaded after existing styles; JS enables this on the eight book domains.
 * Original header rules remain intact for other sites and easy rollback.
 */
#navbar.book-site-header,
#navbar.book-site-header * { box-sizing: border-box; }

#navbar.book-site-header {
  width: 100%;
  max-width: none;
  min-height: 0;
  margin: 0;
  padding: 0;
  border: 0;
  border-bottom: 3px solid var(--book-header-border, #777);
  border-radius: 0;
  background: var(--book-header-bg, #222);
  color: var(--book-header-link, #fff);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.4;
  overflow: visible;
  z-index: 100;
}
#navbar.book-site-header .book-header__row,
#navbar.book-site-header.book-header__row {
  display: block;
  width: 100%;
  max-width: none;
  margin: 0;
  padding: 0 24px;
  overflow: visible;
}
#navbar.book-site-header::before,
#navbar.book-site-header::after,
#navbar.book-site-header .book-header__row::before,
#navbar.book-site-header .book-header__row::after,
#navbar.book-site-header .navbar-header::before,
#navbar.book-site-header .navbar-header::after,
#navbar.book-site-header .navbar-collapse::before,
#navbar.book-site-header .navbar-collapse::after,
#navbar.book-site-header ul.menu::before,
#navbar.book-site-header ul.menu::after { content: none; }

#navbar.book-site-header .navbar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  float: none;
  min-width: 0;
  min-height: 72px;
  margin: 0;
  padding: 12px 0;
}
#navbar.book-site-header .region-navigation { min-width: 0; }
#navbar.book-site-header .navbar-brand {
  float: none;
  width: auto;
  height: auto;
  max-width: 100%;
  margin: 0;
  padding: 0;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 28px;
  font-weight: 400;
  font-style: normal;
  font-variant: normal;
  line-height: 1.2;
  letter-spacing: normal;
  text-transform: none;
  text-shadow: none;
  text-decoration: none;
  white-space: normal;
  overflow-wrap: anywhere;
  color: var(--book-header-title, #fff);
  background: transparent;
  /* The legacy stylesheet sets the brand z-index with !important. */
  z-index: auto !important;
}
#navbar.book-site-header .navbar-brand:hover,
#navbar.book-site-header .navbar-brand:focus {
  color: var(--book-header-title-hover, #fff);
  background: transparent;
}
#navbar.book-site-header .navbar-toggle {
  display: block;
  flex: 0 0 44px;
  float: none;
  width: 44px;
  height: 44px;
  margin: 0;
  padding: 11px 10px;
  border: 1px solid var(--book-header-link, #fff);
  border-radius: 4px;
  background: transparent;
}
#navbar.book-site-header .navbar-toggle:hover,
#navbar.book-site-header .navbar-toggle:focus {
  background: var(--book-header-hover-bg, #000);
}
#navbar.book-site-header .navbar-toggle .icon-bar {
  width: 22px;
  height: 2px;
  background: var(--book-header-link, #fff);
}
#navbar.book-site-header .navbar-collapse {
  float: none;
  width: 100%;
  min-width: 0;
  max-height: none;
  margin: 0;
  padding: 0;
  border: 0;
  box-shadow: none;
  background: transparent;
  font-size: 16px;
  overflow: visible;
  z-index: 1;
}
/* Override Bootstrap's fixed 768px collapse breakpoint. */
#navbar.book-site-header .navbar-collapse.collapse { display: none !important; }
#navbar.book-site-header .navbar-collapse.collapse.in { display: block !important; }
#navbar.book-site-header .navbar-collapse.collapsing { overflow: hidden; }
#navbar.book-site-header .region-navigation-collapsible {
  display: block;
  width: 100%;
  padding: 0 0 12px;
}
#navbar.book-site-header .region-navigation-collapsible > nav {
  float: none;
  width: auto;
  min-width: 0;
  margin: 0;
  padding: 0;
}
#navbar.book-site-header ul.menu {
  display: block;
  float: none !important;
  width: auto;
  margin: 0;
  padding: 0;
  list-style: none;
}
#navbar.book-site-header ul.menu > li,
#navbar.book-site-header .dropdown-menu > li {
  float: none;
  clear: none;
  width: auto;
  margin: 0;
  padding: 0;
  font-size: 16px;
  font-weight: 400;
  background: transparent;
}
#navbar.book-site-header ul.menu > li > a,
#navbar.book-site-header .dropdown-menu > li > a {
  display: block;
  width: auto;
  min-height: 44px;
  margin: 0;
  padding: 11px 12px;
  border: 0;
  border-radius: 4px;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  font-weight: 400;
  font-style: normal;
  font-variant: normal;
  line-height: 22px;
  letter-spacing: normal;
  text-transform: none;
  text-shadow: none;
  text-decoration: none;
  white-space: normal;
  overflow-wrap: anywhere;
  color: var(--book-header-link, #fff);
  background: transparent;
}
#navbar.book-site-header ul.menu > li > a:hover,
#navbar.book-site-header ul.menu > li > a:focus,
#navbar.book-site-header ul.menu > li.open > a,
#navbar.book-site-header ul.menu > li.active > a,
#navbar.book-site-header ul.menu > li > a.is-active {
  color: var(--book-header-hover-link, #fff);
  background: var(--book-header-hover-bg, #000);
}
#navbar.book-site-header a:focus-visible,
#navbar.book-site-header button:focus-visible {
  outline: 2px solid var(--book-header-focus, #fff);
  outline-offset: -2px;
}
#navbar.book-site-header .dropdown-menu {
  display: none;
  position: static;
  float: none;
  width: auto;
  min-width: 0;
  max-width: 100%;
  margin: 0 0 8px;
  padding: 6px;
  border: 1px solid var(--book-header-border, #777);
  border-radius: 4px;
  background: var(--book-header-menu-bg, #222);
  box-shadow: none;
  font-size: 16px;
  line-height: 1.4;
  z-index: 1000;
}
#navbar.book-site-header .open > .dropdown-menu { display: block; }
#navbar.book-site-header .dropdown-menu > li > a {
  color: var(--book-header-menu-link, #fff);
  background: transparent;
}
/* Legacy BP dropdown hover declarations use !important. */
#navbar.book-site-header .dropdown-menu > li > a:hover,
#navbar.book-site-header .dropdown-menu > li > a:focus,
#navbar.book-site-header .dropdown-menu > li.active > a,
#navbar.book-site-header .dropdown-menu > li > a.is-active {
  color: var(--book-header-hover-link, #fff) !important;
  background-color: var(--book-header-hover-bg, #000) !important;
}

/* JS chooses desktop mode only when the full header fits. */
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring).book-header__row,
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .book-header__row {
  display: flex;
  align-items: center;
  flex-wrap: nowrap;
  gap: 24px;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .navbar-header {
  flex: 0 0 auto;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .navbar-brand {
  white-space: nowrap;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .navbar-toggle {
  display: none;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .navbar-collapse {
  display: block !important;
  flex: 1 1 auto;
  width: auto;
  height: auto !important;
  overflow: visible !important;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .region-navigation-collapsible {
  display: flex;
  align-items: center;
  gap: 24px;
  min-width: max-content;
  padding: 0;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .region-navigation-collapsible > nav {
  flex: 0 0 auto;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) #block-useraccountmenu {
  margin-left: auto;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) ul.menu {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) ul.menu > li > a {
  white-space: nowrap;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  right: auto;
  width: 300px;
  max-width: calc(100vw - 48px);
  margin: 0;
  box-shadow: 0 6px 12px #0005;
}
#navbar.book-site-header:is(.book-header--wide, .book-header--measuring) .menu--account .dropdown-menu {
  left: auto;
  right: 0;
}
#navbar.book-site-header.book-header--measuring .navbar-collapse {
  flex: 0 0 auto;
}
#navbar.book-site-header.book-header--measuring .region-navigation-collapsible {
  width: max-content;
}
@media (max-width: 767px) {
  #navbar.book-site-header .book-header__row,
  #navbar.book-site-header.book-header__row { padding: 0 16px; }
  #navbar.book-site-header:not(.book-header--measuring) .navbar-brand { font-size: 22px; }
}