/* ==========================================================================
   Smart sticky header
   Transparent with light text over the dark hero; themed glass once scrolled.
   ========================================================================== */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  padding-block: 20px;
  color: var(--text-light);
  transition:
    padding-block 0.3s var(--ease-out-expo),
    background-color 0.3s ease,
    box-shadow 0.3s ease,
    color 0.3s ease;
}

.site-header.is-scrolled,
.site-header.is-open {
  padding-block: 12px;
  background: var(--header-bg);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  box-shadow:
    0 1px 0 var(--border-subtle),
    0 4px 20px rgba(0, 0, 0, 0.06);
  color: var(--text-heading);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

/* --- Logo (text wordmark) ----------------------------------------------- */
.logo {
  display: inline-flex;
  flex-direction: column;
  margin-right: auto;
  line-height: 1;
}

.logo__name {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.logo__tag {
  margin-top: 3px;
  font-size: 0.6rem;
  font-weight: 600;
  letter-spacing: 0.42em;
  text-transform: uppercase;
  color: var(--color-gold);
}

.site-header.is-scrolled .logo__tag,
.site-header.is-open .logo__tag {
  color: var(--color-gold-text);
}

.logo:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 4px;
  border-radius: 4px;
}

/* --- Navigation --------------------------------------------------------- */
.site-nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.site-nav__list {
  display: flex;
  gap: 1.75rem;
  list-style: none;
}

.site-nav__link {
  position: relative;
  padding-block: 0.25rem;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.site-nav__link::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -2px;
  left: 0;
  height: 1px;
  background: var(--color-gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease-out-expo);
}

.site-nav__link:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 4px;
  border-radius: 2px;
}

@media (hover: hover) {
  .site-nav__link:hover::after {
    transform: scaleX(1);
  }
}

.site-nav__cta {
  min-height: 44px;
  padding: 0.6rem 1.4rem;
  font-size: 0.85rem;
}

/* --- Header actions: theme toggle + menu button ------------------------- */
.site-header__actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid color-mix(in srgb, currentColor 28%, transparent);
  border-radius: 50%;
  background: transparent;
  color: inherit;
  font-size: 18px;
  cursor: pointer;
  transition:
    border-color 0.3s ease,
    color 0.3s ease;
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 3px;
}

@media (hover: hover) {
  .theme-toggle:hover {
    border-color: var(--color-gold);
    color: var(--color-gold);
  }
}

.theme-toggle__icon {
  grid-area: 1 / 1;
  transition:
    opacity 0.3s ease,
    transform 0.5s var(--ease-out-expo);
}

/* Light theme shows the moon (switch to dark); dark theme shows the sun */
:root[data-theme="dark"] .theme-toggle__icon--moon,
:root:not([data-theme="dark"]) .theme-toggle__icon--sun {
  opacity: 0;
  transform: rotate(-90deg) scale(0.6);
}

.nav-toggle {
  display: none;
}

/* --- Mobile menu -------------------------------------------------------- */
@media (max-width: 899px) {
  .nav-toggle {
    display: inline-flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    padding: 10px;
    border: 0;
    background: none;
    color: inherit;
    cursor: pointer;
  }

  .nav-toggle:focus-visible {
    outline: 2px solid var(--color-gold);
    border-radius: 8px;
  }

  .nav-toggle__bar {
    display: block;
    width: 100%;
    height: 2px;
    border-radius: 2px;
    background: currentColor;
    transition:
      transform 0.3s var(--ease-out-expo),
      opacity 0.2s ease;
  }

  .is-open .nav-toggle__bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .is-open .nav-toggle__bar:nth-child(2) {
    opacity: 0;
  }

  .is-open .nav-toggle__bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  /* absolute, not fixed: backdrop-filter on the header makes it the containing block */
  .site-nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 1.25rem;
    padding: 0.5rem var(--gutter) 1.75rem;
    background: var(--bg-elevated);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.12);
    color: var(--text-heading);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition:
      opacity 0.3s ease,
      transform 0.3s var(--ease-out-expo),
      visibility 0s linear 0.3s;
  }

  .is-open .site-nav {
    opacity: 1;
    visibility: visible;
    transform: none;
    transition-delay: 0s;
  }

  .site-nav__list {
    flex-direction: column;
    gap: 0;
  }

  .site-nav__link {
    display: block;
    padding-block: 0.85rem;
    font-size: 1rem;
    border-bottom: 1px solid var(--border-subtle);
  }

  .site-nav__link::after {
    display: none;
  }

  .site-nav__cta {
    min-height: 48px;
  }
}