/* ---------- Sticky header: a rail that detaches from the page once you scroll ---------- */
/* The header box stays a fixed size at every scroll position: the scrolled
   state is a paint change only (surface, blur, hairline, shadow). Animating
   its padding or the logo's height would relayout the sticky bar on every
   scroll threshold and jitter the content beneath it. */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding-block: var(--space-xs);
}

/* The rail spans exactly the page container, so the logo lines up with the
   content below it in both the resting and the scrolled state. */
.site-header__inner {
  position: relative;
  max-width: var(--container-max);
  margin-inline: auto;
  padding: 0.5rem var(--container-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  border: 1px solid transparent;
  border-radius: var(--radius-lg);
  transition: background var(--duration-normal) var(--ease-out-expo),
              border-color var(--duration-normal) var(--ease-out-expo),
              box-shadow var(--duration-normal) var(--ease-out-expo);
}
.site-header.is-scrolled .site-header__inner {
  background: color-mix(in srgb, var(--color-cream) 82%, transparent);
  backdrop-filter: blur(16px) saturate(1.4);
  -webkit-backdrop-filter: blur(16px) saturate(1.4);
  border-color: var(--color-border);
  box-shadow: 0 10px 30px color-mix(in srgb, var(--color-teal) 12%, transparent);
}

/* Below the container width the rail has no room to float, so it reads as a
   full-width bar instead of a capsule with corners clipped at the viewport. */
@media (max-width: 1320px) {
  .site-header.is-scrolled .site-header__inner {
    border-radius: 0;
    border-inline-color: transparent;
    border-top-color: transparent;
  }
}

.site-header__brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  border-radius: var(--radius-md);
}
.site-header__logo-mark {
  display: block;
  height: clamp(2.7rem, 2.2rem + 1.2vw, 3.5rem);
  width: auto;
  flex-shrink: 0;
  transform-origin: left center;
  transition: transform var(--duration-normal) var(--ease-out-expo);
}
.site-header__brand:hover .site-header__logo-mark { transform: scale(1.04); }

.site-header__toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  padding: 0;
  transition: background var(--duration-fast) var(--ease-out-expo),
              border-color var(--duration-fast) var(--ease-out-expo);
}
.site-header__toggle:hover { background: var(--color-teal-pale); border-color: transparent; }
.site-header__toggle-bars { display: block; width: 22px; }
.site-header__toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  margin: 5px 0;
  background: var(--color-ink);
  border-radius: var(--radius-full);
  transition: transform var(--duration-normal) var(--ease-out-expo), opacity var(--duration-fast);
}
.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(2) { opacity: 0; }
.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.site-header__nav { display: flex; align-items: center; gap: var(--space-sm); }

.site-header__link {
  position: relative;
  color: var(--color-ink);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.4rem 0.15rem;
  white-space: nowrap;
  transition: color var(--duration-fast) var(--ease-out-expo);
}
.site-header__link::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.05rem;
  height: 2px;
  border-radius: var(--radius-full);
  background: var(--color-terracotta);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--duration-normal) var(--ease-out-expo);
}
.site-header__link:hover,
.site-header__link:focus-visible { color: var(--color-teal); }
.site-header__link:hover::after,
.site-header__link:focus-visible::after,
.site-header__link[aria-current="page"]::after { transform: scaleX(1); }
.site-header__link[aria-current="page"] { color: var(--color-teal); font-weight: 700; }

.site-header__cta {
  margin-left: var(--space-2xs);
  background: var(--color-terracotta);
  color: var(--color-cream);
  padding: 0.55rem 1.15rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  white-space: nowrap;
  text-decoration: none;
  box-shadow: 0 2px 8px color-mix(in srgb, var(--color-terracotta) 28%, transparent);
  transition: transform var(--duration-fast) var(--ease-out-expo),
              box-shadow var(--duration-fast) var(--ease-out-expo);
}
.site-header__cta:hover,
.site-header__cta:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px color-mix(in srgb, var(--color-terracotta) 34%, transparent);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--color-teal);
  color: var(--color-cream);
  padding: 0.6rem 1rem;
  z-index: 300;
}
.skip-link:focus { left: 0.5rem; top: 0.5rem; }

/* ---------- Mobile: the nav drops as a panel matching the rail ---------- */
@media (max-width: 980px) {
  .site-header__toggle { display: inline-flex; }
  .site-header__nav {
    position: absolute;
    top: calc(100% + 0.5rem);
    left: var(--container-pad);
    right: var(--container-pad);
    flex-direction: column;
    align-items: stretch;
    gap: 0.15rem;
    background: color-mix(in srgb, var(--color-cream) 94%, var(--color-surface));
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: var(--space-2xs);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-0.5rem);
    transition: opacity var(--duration-normal) var(--ease-out-expo),
                transform var(--duration-normal) var(--ease-out-expo),
                visibility var(--duration-normal);
  }
  .site-header__nav.is-open { opacity: 1; visibility: visible; transform: none; }

  .site-header__link {
    display: flex;
    align-items: center;
    min-height: 3rem;
    padding: 0.5rem var(--space-sm);
    border-radius: var(--radius-md);
    font-size: var(--text-base);
    transition: background var(--duration-fast) var(--ease-out-expo),
                color var(--duration-fast) var(--ease-out-expo);
  }
  .site-header__link::after { display: none; }
  .site-header__link:hover { background: var(--color-teal-pale); }
  .site-header__link[aria-current="page"] { background: var(--color-teal-pale); }

  .site-header__cta {
    margin: var(--space-2xs) 0 0;
    text-align: center;
    padding-block: 0.85rem;
    border-radius: var(--radius-md);
  }
}

@media (prefers-reduced-motion: reduce) {
  .site-header__nav { transition: opacity 0.001ms, visibility 0.001ms; }
}

/* ---------- Topbar ---------- */
.site-topbar {
  background: var(--color-teal-dark);
  color: color-mix(in srgb, var(--color-cream) 88%, transparent);
  font-size: var(--text-xs);
}
.site-topbar__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0.4rem var(--container-pad);
  display: flex;
  align-items: center;
  gap: var(--space-2xs);
  flex-wrap: wrap;
}
.site-topbar a { color: inherit; text-decoration: none; }
.site-topbar a:hover { text-decoration: underline; }
.site-topbar__sep { opacity: 0.5; }

@media (max-width: 640px) {
  .site-topbar { display: none; }
}