/* B&S Transport GmbH — Header & Navigation
   Entscheidungen: CONTEXT.md D-15 bis D-24 */

/* === SITE HEADER === */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--transition-fast);
}

/* .scrolled wird via JS (nav.js) bei scrollY > 50px gesetzt — D-16 */
.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1280px;
  margin-inline: auto;
  padding-inline: var(--space-lg);
  height: 72px;
}

/* === LOGO (Textbasiert — kein img, D-17) === */
.site-logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-navy);
  text-decoration: none;
  letter-spacing: -0.02em;
  flex-shrink: 0;
}

.site-logo span {
  color: var(--color-accent);
}

/* === DESKTOP NAVIGATION === */
.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-2xl);
}

.nav-links-desktop {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-links-desktop a {
  font-size: var(--font-size-base);
  font-weight: 500;
  color: var(--color-text);
  text-decoration: none;
  padding-block: var(--space-xs);
  border-bottom: 2px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.nav-links-desktop a:hover {
  color: var(--color-navy);
  border-bottom-color: var(--color-accent);
}

/* Aktive Seite — D-19 */
.nav-links-desktop a.active {
  color: var(--color-navy);
  border-bottom-color: var(--color-accent);
  font-weight: 600;
}

/* Focus-visible für Desktop-Nav-Links (A11Y-03 — Gap aus Research) */
.nav-links-desktop a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 2px;
}

/* === SPRACHUMSCHALTER (Desktop) — D-18 === */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.lang-switcher a {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text-light);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: color var(--transition-fast),
              border-color var(--transition-fast),
              background-color var(--transition-fast);
}

.lang-switcher a:hover {
  color: var(--color-navy);
  border-color: var(--color-navy);
}

.lang-switcher a.active,
.lang-switcher a[aria-current="page"] {
  color: var(--color-navy);
  background-color: var(--color-bg-subtle);
  border-color: var(--color-border);
  font-weight: 700;
}

/* Focus-visible für Desktop-Sprachumschalter (A11Y-03) */
.lang-switcher a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* === HAMBURGER BUTTON (nur mobile) — D-20, A11Y: <button> Pflicht === */
.hamburger-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;   /* Mindestgröße 44px für Touch-Targets (WCAG 2.5.5) */
  height: 44px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast);
}

.hamburger-btn:hover {
  background-color: var(--color-bg-subtle);
}

.hamburger-btn:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* Die drei Striche */
.hamburger-line {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-navy);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* X-Animation wenn Menü offen */
.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}
.hamburger-btn[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* === MOBILE OVERLAY — D-20 bis D-24 === */
.nav-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-overlay);
  background-color: var(--color-navy-dark);  /* #0a1628, D-21 */
  display: flex;
  flex-direction: column;
  padding: var(--space-lg);

  /* Versteckt-Zustand: opacity + transform (D-24: keine komplexe Animation) */
  opacity: 0;
  transform: translateY(-8px);
  pointer-events: none;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

/* Offen-Zustand — via JS .is-open gesetzt */
.nav-overlay.is-open {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}

.overlay-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-2xl);
}

.overlay-logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-inverse);
}

/* Schließen-Button (X) — D-23 */
.overlay-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid var(--color-border-dark);
  border-radius: var(--radius-md);
  color: var(--color-text-inverse);
  font-size: var(--font-size-lg);
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.overlay-close:hover {
  background-color: var(--color-navy-light);
}

.overlay-close:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* Nav-Links im Overlay — D-22: min. 1.5rem, großes Padding */
.nav-links-overlay {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.nav-links-overlay a {
  font-size: var(--font-size-2xl);   /* min. 1.5rem — D-22 */
  font-weight: 600;
  color: var(--color-text-inverse);
  padding: var(--space-md) var(--space-sm);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast), color var(--transition-fast);
  border-bottom: 1px solid var(--color-border-dark);
}

.nav-links-overlay a:last-child {
  border-bottom: none;
}

.nav-links-overlay a:hover {
  background-color: var(--color-navy-light);
}

.nav-links-overlay a.active {
  color: var(--color-accent);
}

/* Focus-visible für Overlay-Nav-Links (A11Y-03) */
.nav-links-overlay a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: var(--radius-md);
}

/* Sprachumschalter im Overlay */
.lang-switcher-overlay {
  display: flex;
  gap: var(--space-sm);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border-dark);
  margin-top: var(--space-lg);
}

.lang-switcher-overlay a {
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text-inverse);
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border-dark);
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.lang-switcher-overlay a:hover {
  background-color: var(--color-navy-light);
  border-color: var(--color-text-inverse);
}

.lang-switcher-overlay a.active,
.lang-switcher-overlay a[aria-current="page"] {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
}

/* === RESPONSIVE: Hamburger sichtbar, Desktop-Nav versteckt === */
@media (max-width: 768px) {
  .hamburger-btn {
    display: flex;
  }

  .nav-links-desktop,
  .lang-switcher {
    display: none;
  }
}

@media (min-width: 769px) {
  .nav-overlay {
    display: none;  /* Kein Overlay auf Desktop */
  }
}