/* Purpose: Site header and primary navigation.
   The logo is a pure-white PNG, so the header is never given a light background. */

.site-header {
  position: fixed;
  inset-inline: 0;
  top: 0;
  z-index: var(--z-sticky);
  background-color: transparent;
  color: var(--color-text-invert);
  transition:
    background-color var(--duration-slow) var(--ease-out),
    backdrop-filter var(--duration-slow) var(--ease-out),
    box-shadow var(--duration-base) var(--ease-out),
    transform var(--duration-slow) var(--ease-out);
}

body:not(.home) .site-header {
  background-color: rgba(15, 0, 4, 0.92);
  -webkit-backdrop-filter: blur(14px);
          backdrop-filter: blur(14px);
}

.site-header.is-stuck {
  background-color: rgba(15, 0, 4, 0.86);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
          backdrop-filter: blur(16px) saturate(140%);
  box-shadow: 0 1px 0 var(--color-border), var(--shadow-md);
}

.site-header.is-hidden { transform: translateY(-100%); }

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  min-height: 96px;
  transition: min-height var(--duration-slow) var(--ease-out);
}

.site-header.is-stuck .site-header__inner { min-height: 76px; }

.site-header__brand { display: inline-flex; align-items: center; }

.site-header__logo {
  max-height: 58px;
  width: auto;
  transition: max-height var(--duration-slow) var(--ease-out);
}
.site-header.is-stuck .site-header__logo { max-height: 44px; }

.site-header__wordmark {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-bold);
  color: var(--color-text-invert);
}

.site-header__toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px; height: 44px;
  padding: var(--space-2);
  background: none;
  border: 0;
  cursor: pointer;
}

.site-header__toggle-bar {
  display: block;
  height: 2px;
  width: 100%;
  background-color: var(--color-text-invert);
  transition: transform var(--duration-base) var(--ease-out), opacity var(--duration-fast) linear;
}

.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-nav {
  position: fixed;
  inset: 96px 0 auto;
  max-height: 0;
  overflow: hidden;
  background-color: rgba(15, 0, 4, 0.98);
  -webkit-backdrop-filter: blur(16px);
          backdrop-filter: blur(16px);
  transition: max-height var(--duration-slow) var(--ease-out);
}

.site-nav.is-open { max-height: calc(100dvh - 96px); overflow-y: auto; }

.site-nav__list { list-style: none; margin: 0; padding: var(--space-4) var(--gutter); }
.site-nav__list li { border-bottom: 1px solid var(--color-border); }
.site-nav__list a {
  display: block;
  padding: var(--space-5) 0;
  color: var(--color-text);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-widest);
  text-transform: uppercase;
}
.site-nav__cta { margin: var(--space-8) var(--gutter); }

@media (min-width: 1025px) {
  .site-header__toggle { display: none; }

  .site-nav {
    position: static;
    max-height: none;
    overflow: visible;
    display: flex;
    align-items: center;
    gap: var(--space-10);
    background: none;
    -webkit-backdrop-filter: none;
            backdrop-filter: none;
  }

  .site-nav__list { display: flex; align-items: center; gap: var(--space-8); padding: 0; }
  .site-nav__list li { border: 0; }

  .site-nav__list a {
    position: relative;
    padding: var(--space-2) 0;
    font-size: 0.6875rem;
    font-weight: var(--weight-semibold);
    letter-spacing: var(--tracking-widest);
    color: var(--color-text-muted);
  }
  .site-nav__list a:hover { color: var(--color-text-invert); }

  .site-nav__list a::after {
    content: '';
    position: absolute;
    left: 0; bottom: -2px;
    width: 100%; height: 1.5px;
    background: var(--gradient-gold-soft);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--duration-base) var(--ease-out);
  }
  .site-nav__list a:hover::after,
  .site-nav__list a:focus-visible::after,
  .site-nav__list .current-menu-item > a::after { transform: scaleX(1); }

  .site-nav__cta { margin: 0; padding: var(--space-4) var(--space-8); font-size: 0.6875rem; }
}