/* ============================================================
   header.css — sticky site header, primary nav, off-canvas drawer.
   Mobile-first: drawer + hamburger by default; inline nav at >=992px.
   ============================================================ */

.site-header {
  position: sticky;
  inset-block-start: 0;
  z-index: 200;               /* sticky-header layer (Fix 7 convention) */
  background: var(--color-bg);
  border-block-end: 1px solid var(--color-border);
  transition: box-shadow var(--transition-base);
}
.site-header.is-scrolled { box-shadow: var(--shadow-md); }

.site-header__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-lg);
  min-block-size: 72px;
  padding-block: var(--space-sm);
}

.site-header__logo { display: inline-flex; align-items: center; }
.site-header__logo img { block-size: 40px; inline-size: auto; }
@media (min-width: 768px) { .site-header__logo img { block-size: 46px; } }

/* ---- Primary nav (inline list) ---- */
.nav-primary { display: flex; align-items: center; }
.nav-primary__list { display: flex; align-items: center; gap: var(--space-xs); }
.nav-primary__link {
  display: inline-flex;
  align-items: center;
  min-block-size: 44px;
  padding-inline: var(--space-md);
  font-family: var(--font-heading);
  font-size: var(--fs-md);
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  position: relative;
  transition: color var(--transition-fast), background var(--transition-fast);
}
.nav-primary__link:hover { color: var(--color-primary); }
.nav-primary__link[aria-current="page"] { color: var(--color-primary); font-weight: 600; }
.nav-primary__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  inset-block-end: 6px;
  inset-inline: var(--space-md);
  block-size: 2px;
  background: var(--gradient-accent);
}

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

/* ---- Hamburger toggle ---- */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-inline-size: 44px;
  min-block-size: 44px;
  border-radius: var(--radius-sm);
  color: var(--color-primary-deep);
}
.nav-toggle:hover { background: var(--color-surface); }
.nav-toggle .icon { inline-size: 26px; block-size: 26px; }
.nav-toggle__close { display: none; }
.nav-toggle[aria-expanded="true"] .nav-toggle__open { display: none; }
.nav-toggle[aria-expanded="true"] .nav-toggle__close { display: block; }

/* ---- Off-canvas drawer (mobile) ---- */
.nav-drawer {
  position: fixed;
  inset-block: 0;
  inset-inline-end: 0;
  z-index: 500;
  inline-size: min(360px, 86vw);
  background: var(--color-bg);
  border-inline-start: 1px solid var(--color-border);
  box-shadow: var(--shadow-lg);
  transform: translateX(100%);
  visibility: hidden;                 /* keep closed-drawer links out of the tab order */
  transition: transform var(--transition-base), visibility 0s linear var(--transition-base);
  display: flex;
  flex-direction: column;
  padding: var(--space-lg);
  overflow-y: auto;
}
[dir="rtl"] .nav-drawer { transform: translateX(-100%); }
.nav-drawer.is-open {
  transform: translateX(0);
  visibility: visible;
  transition: transform var(--transition-base), visibility 0s;
}

.nav-drawer__head { display: flex; align-items: center; justify-content: space-between; margin-block-end: var(--space-lg); }
.nav-drawer__logo { block-size: 36px; inline-size: auto; }
.nav-drawer__list { display: flex; flex-direction: column; gap: var(--space-xs); }
.nav-drawer__link {
  display: flex;
  align-items: center;
  min-block-size: 48px;
  padding-inline: var(--space-md);
  font-family: var(--font-heading);
  font-size: var(--fs-lg);
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  border-inline-start: 3px solid transparent;
}
.nav-drawer__link:hover { background: var(--color-surface); color: var(--color-primary); }
.nav-drawer__link[aria-current="page"] {
  color: var(--color-primary);
  font-weight: 600;
  border-inline-start-color: var(--color-accent);
  background: var(--color-surface);
}
.nav-drawer__cta { margin-block-start: var(--space-lg); }

/* Backdrop */
.nav-backdrop {
  position: fixed;
  inset: 0;
  z-index: 499;
  background: var(--color-scrim);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base);
}
.nav-backdrop.is-open { opacity: 1; visibility: visible; }

/* Lock body scroll when drawer open */
body.has-drawer-open { overflow: hidden; }

/* ============================================================
   RESPONSIVE — inline nav at >=992px, hide drawer machinery
   ============================================================ */
.nav-primary { display: none; }
.site-header__cta { display: none; }

@media (min-width: 600px) {
  .site-header__cta { display: inline-flex; }
}
@media (min-width: 992px) {
  .nav-primary { display: flex; }
  .nav-toggle { display: none; }
  .nav-drawer, .nav-backdrop { display: none; }
}