/* Tandem V2.23: one shared, borderless header. Keep opacity on the surface only. */
.site-header {
  --header-height: 78px;
  --header-paper: #fffdf9;
  --header-ink: #0b211a;
  --header-muted: #516257;
  --header-sage: #f1f5ee;
  --header-accent: #25523f;
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
  min-width: 0;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: var(--header-paper);
  color: var(--header-ink);
  box-shadow: none;
  transition: background-color 180ms ease, box-shadow 180ms ease;
}
.site-header.is-scrolled { box-shadow: 0 5px 20px rgba(11, 33, 26, .035); }
@supports ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .site-header {
    background: rgba(255, 253, 249, .90);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
  }
  .site-header.is-scrolled { background: rgba(255, 253, 249, .97); }
  .site-header.is-menu-open { background: var(--header-paper); }
}
.site-header .nav {
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(16px, 2vw, 32px);
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  min-width: 0;
}
.site-header .brand { display: inline-flex; align-items: center; flex: 0 0 auto; min-height: 44px; }
.site-header .brand img { display: block; width: 136px; height: auto; }
.site-header .desktop-nav { display: flex; align-items: center; gap: clamp(6px, 1vw, 18px); min-width: 0; }
.site-header .desktop-nav > a,
.site-header .nav-dropdown-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 9px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--header-ink);
  font-family: inherit;
  font-size: .875rem;
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: 0;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  transition: color 160ms ease, background-color 160ms ease;
}
.site-header .desktop-nav > a::after { display: none; }
.site-header .desktop-nav > a:hover,
.site-header .nav-dropdown-toggle:hover,
.site-header .nav-dropdown-toggle[aria-expanded="true"] {
  color: var(--header-accent);
  background: var(--header-sage);
}
.site-header .desktop-nav > a[aria-current="page"],
.site-header .nav-dropdown-toggle[data-current="true"] { color: var(--header-accent); }
.site-header .nav-item { position: relative; display: flex; align-items: center; }
.site-header .nav-caret {
  display: inline-block;
  width: 7px;
  height: 7px;
  margin: 0 2px 3px 0;
  border: 0;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg);
  transform-origin: center;
  transition: transform 160ms ease;
}
.site-header .nav-dropdown-toggle[aria-expanded="true"] .nav-caret { transform: translateY(3px) rotate(225deg); }
.site-header .nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 12px);
  left: 50%;
  z-index: 110;
  width: 332px;
  max-width: calc(100vw - 32px);
  padding: 8px;
  border: 0;
  border-radius: 16px;
  background: var(--header-paper);
  box-shadow: 0 14px 36px rgba(11, 33, 26, .12);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translate(-50%, -5px);
  transition: opacity 160ms ease, transform 160ms ease, visibility 160ms ease;
}
.site-header .nav-dropdown-menu::before { content: ""; position: absolute; left: 0; right: 0; top: -14px; height: 14px; }
.site-header .has-dropdown.open .nav-dropdown-menu,
.site-header:not([data-nav-ready]) .has-dropdown:hover .nav-dropdown-menu,
.site-header:not([data-nav-ready]) .has-dropdown:focus-within .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translate(-50%, 0);
}
.site-header .nav-dropdown-menu a {
  display: grid;
  gap: 4px;
  padding: 13px 14px;
  min-height: 64px;
  border-radius: 10px;
  text-decoration: none;
  transition: background-color 160ms ease;
}
.site-header .nav-dropdown-menu a::after { display: none; }
.site-header .nav-dropdown-menu a:hover,
.site-header .nav-dropdown-menu a[aria-current="page"] { background: var(--header-sage); }
.site-header .nav-dropdown-menu strong { font-size: .875rem; font-weight: 600; color: var(--header-ink); }
.site-header .nav-dropdown-menu span { font-size: .765rem; font-weight: 400; line-height: 1.5; color: var(--header-muted); }
.site-header .nav-actions { display: flex; align-items: center; gap: 12px; flex: 0 0 auto; }
.site-header .nav-actions .button,
.site-header .mobile-menu-actions .button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 11px 20px;
  border: 1px solid transparent;
  border-radius: 999px;
  background: var(--header-ink);
  color: #fff;
  font-family: inherit;
  font-size: .8125rem;
  font-weight: 600;
  line-height: 1.3;
  text-align: center;
  white-space: nowrap;
  box-shadow: none;
  transform: none;
  transition: background-color 160ms ease, color 160ms ease;
}
.site-header .nav-actions .button:hover,
.site-header .mobile-menu-actions .button:hover { background: var(--header-accent); color: #fff; box-shadow: none; transform: none; }
.site-header .nav-actions .button:active,
.site-header .mobile-menu-actions .button:active { background: var(--header-ink); transform: none; }
.site-header a:focus-visible,
.site-header button:focus-visible,
.site-header summary:focus-visible {
  outline: 2px solid var(--header-accent);
  outline-offset: 4px;
}
.site-header .mobile-toggle {
  display: none;
  position: relative;
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  flex: 0 0 44px;
  padding: 0;
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: var(--header-ink);
  cursor: pointer;
}
.site-header .mobile-toggle:hover { background: var(--header-sage); }
.site-header .mobile-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 5px auto;
  border-radius: 2px;
  background: currentColor;
  transition: transform 160ms ease;
}
.site-header .mobile-toggle[aria-expanded="true"] span:first-child { transform: translateY(3.5px) rotate(45deg); }
.site-header .mobile-toggle[aria-expanded="true"] span:last-child { transform: translateY(-3.5px) rotate(-45deg); }
.site-header .mobile-menu { display: none; }

@media (max-width: 1100px) and (min-width: 981px) {
  .site-header .nav { gap: 16px; }
  .site-header .desktop-nav { gap: 4px; }
  .site-header .desktop-nav > a,
  .site-header .nav-dropdown-toggle { padding-inline: 7px; font-size: .8125rem; }
  .site-header .nav-actions .button { padding-inline: 16px; }
}
@media (max-width: 980px) {
  .site-header { --header-height: 72px; }
  .site-header .desktop-nav { display: none; }
  .site-header .mobile-toggle { display: block; }
  .site-header .mobile-menu {
    display: block;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    width: 100%;
    margin: 0;
    padding: 0;
    max-height: calc(100vh - var(--header-height));
    max-height: calc(100dvh - var(--header-height));
    overflow-y: auto;
    overscroll-behavior: contain;
    border: 0;
    border-radius: 0;
    background: var(--header-paper);
    box-shadow: 0 18px 28px rgba(11, 33, 26, .08);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-4px);
    transition: opacity 160ms ease, transform 160ms ease, visibility 160ms ease;
  }
  .site-header .mobile-menu.open { opacity: 1; visibility: visible; pointer-events: auto; transform: none; }
  .site-header .mobile-menu > .shell { display: grid; padding-block: 6px 24px; }
  .site-header .mobile-menu > .shell > a,
  .site-header .mobile-nav-group summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 52px;
    padding: 12px 0;
    font-size: .9375rem;
    font-weight: 600;
    line-height: 1.4;
    color: var(--header-ink);
    border: 0;
    text-decoration: none;
    cursor: pointer;
  }
  .site-header .mobile-nav-group { border: 0; }
  .site-header .mobile-nav-group summary { list-style: none; }
  .site-header .mobile-nav-group summary::-webkit-details-marker { display: none; }
  .site-header .mobile-nav-group summary::after {
    content: "";
    width: 8px;
    height: 8px;
    margin: 0 5px 4px 12px;
    border-right: 1.5px solid currentColor;
    border-bottom: 1.5px solid currentColor;
    transform: rotate(45deg);
    transition: transform 160ms ease;
  }
  .site-header .mobile-nav-group[open] summary::after { transform: translateY(4px) rotate(225deg); }
  .site-header .mobile-nav-sub { display: grid; gap: 2px; padding: 0 0 8px 12px; }
  .site-header .mobile-nav-sub a {
    display: flex;
    align-items: center;
    min-height: 44px;
    padding: 10px 12px;
    border: 0;
    border-radius: 8px;
    color: var(--header-muted);
    font-size: .875rem;
    font-weight: 500;
    line-height: 1.4;
    text-decoration: none;
  }
  .site-header .mobile-nav-sub a:hover,
  .site-header .mobile-nav-sub a[aria-current="page"] { color: var(--header-accent); background: var(--header-sage); }
  .site-header .mobile-menu-actions { display: grid; gap: 12px; padding-top: 16px; }
  .site-header .mobile-menu-actions .button { min-height: 48px; white-space: normal; }
  /* Lock the root, not a body scroll-container: the sticky header stays on screen. */
  html.tandem-menu-open { overflow: hidden; }
  body.menu-open { overflow: clip; }
}
@media (max-width: 680px) {
  .site-header { --header-height: 68px; }
  .site-header .nav { gap: 12px; }
  .site-header .brand img { width: 120px; }
  .site-header .nav-actions { gap: 8px; }
}
@media (max-width: 520px) {
  .site-header .nav-actions > .button { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  .site-header,
  .site-header * { transition: none; }
}
@media (prefers-reduced-transparency: reduce) {
  .site-header,
  .site-header.is-scrolled { background: var(--header-paper); -webkit-backdrop-filter: none; backdrop-filter: none; }
}
@media (forced-colors: active) {
  .site-header,
  .site-header.is-scrolled,
  .site-header .nav-dropdown-menu,
  .site-header .mobile-menu { background: Canvas; color: CanvasText; }
  .site-header .nav-dropdown-menu { border: 1px solid CanvasText; }
}