.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.70);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  transition: box-shadow var(--transition-base);
}

.site-header.is-scrolled {
  box-shadow: 0 4px 16px -4px rgba(15, 17, 21, 0.08),
              0 1px 3px rgba(15, 17, 21, 0.04);
}

.site-header__inner {
  display: grid;
  grid-template-columns: auto auto;
  align-items: center;
  gap: var(--space-4);
  padding-block: var(--space-4);
}

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

.site-header__logo img {
  width: 144px;
  height: auto;
}

/* Nav */
.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(var(--space-4), 3vw, var(--space-10));
}

.site-nav__list a {
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text);
  padding: var(--space-2) 0;
  transition: color var(--transition-fast);
}

.site-nav__list a:hover {
  color: var(--color-primary);
}

.site-header__cta {
  font-weight: var(--fw-semibold);
}

/* Hamburger (mobile only) */
.nav-toggle {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.nav-toggle-btn {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  justify-self: end;
  transition: background-color var(--transition-fast);
}

.nav-toggle-btn:hover {
  background: var(--color-surface);
}

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
  transform-origin: center;
}

/* Animate hamburger to X when open */
.nav-toggle:checked ~ .nav-toggle-btn .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle:checked ~ .nav-toggle-btn .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}
.nav-toggle:checked ~ .nav-toggle-btn .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* === Mobile (default): absolutely positioned drawer below the header === */
@media (max-width: 1023px) {
  .site-nav-drawer {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    padding: var(--space-3) var(--container-px) var(--space-4);
    background: #ffffff;
    border-top: 1px solid var(--color-border);
    box-shadow: 0 12px 24px -8px rgba(15, 17, 21, 0.1);

    /* Hidden state */
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    pointer-events: none;
    transition: max-height var(--transition-base), opacity var(--transition-base);
  }

  .nav-toggle:checked ~ .site-nav-drawer {
    max-height: 480px;
    opacity: 1;
    pointer-events: auto;
  }

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

  .site-nav__list a {
    display: block;
    padding: var(--space-3) var(--space-2);
    border-bottom: 1px solid var(--color-border);
  }

  .site-header__cta {
    align-self: stretch;
    margin-top: var(--space-2);
  }
}

/* === Desktop (1024px+): horizontal layout, drawer is transparent to grid === */
@media (min-width: 1024px) {
  .site-nav-drawer {
    display: contents;
  }

  .site-header__inner {
    grid-template-columns: 1fr auto 1fr;
  }

  .site-header__logo {
    justify-self: start;
  }

  .site-nav {
    justify-self: center;
  }

  .site-header__cta {
    justify-self: end;
  }

  .nav-toggle-btn {
    display: none;
  }
}