/* =========================================================
   HEADER — navigation fixe
   ========================================================= */

.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0);
  border-bottom: 1px solid transparent;
  transition: background var(--dur-base) var(--ease-soft), border-color var(--dur-base) var(--ease-soft), backdrop-filter var(--dur-base) var(--ease-soft), box-shadow var(--dur-base) var(--ease-soft);
}

/* Transparent uniquement sur l'accueil, au tout début du scroll */
body:not(.is-home) .site-header,
.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: blur(14px) saturate(1.2);
  -webkit-backdrop-filter: blur(14px) saturate(1.2);
  border-bottom: 1px solid var(--border-fine);
  box-shadow: 0 1px 0 rgba(18, 59, 115, 0.03);
}

.site-header__inner {
  width: 100%;
  max-width: var(--container-w);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.site-header__brand {
  display: flex;
  align-items: center;
}
.site-header__brand img {
  height: 84px;
  width: auto;
}
@media (max-width: 720px) {
  .site-header__brand img { height: 56px; }
}

.site-header__nav {
  display: flex;
  align-items: center;
  gap: clamp(1.4rem, 2.5vw, 2.4rem);
}
.site-header__nav a {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-primary);
  position: relative;
  padding: 0.4rem 0.05rem;
  transition: color var(--dur-fast) var(--ease-soft);
}
.site-header__nav a::after {
  content: "";
  position: absolute;
  left: 0; right: 100%;
  bottom: -2px;
  height: 2px;
  background: var(--c-azur);
  transition: right var(--dur-base) var(--ease-soft);
}
.site-header__nav a:hover { color: var(--c-ocean); }
.site-header__nav a:hover::after,
.site-header__nav a[aria-current="page"]::after { right: 0; }
.site-header__nav a[aria-current="page"] { color: var(--c-ocean); }

.site-header__actions { display: flex; align-items: center; gap: 1rem; }

.lang-switch {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text-primary);
  border: 1px solid var(--border-fine-strong);
  border-radius: var(--radius-sm);
  padding: 0.55rem 1rem;
  transition: color var(--dur-fast) var(--ease-soft), border-color var(--dur-fast) var(--ease-soft);
}
.lang-switch:hover { color: var(--c-ocean); border-color: var(--c-azur); }
.lang-switch__flag {
  width: 26px;
  height: 18px;
  border-radius: 3px;
  flex-shrink: 0;
  box-shadow: 0 0 0 1px rgba(18, 59, 115, 0.12);
}
@media (max-width: 480px) {
  .lang-switch__flag { width: 22px; height: 15px; }
  .lang-switch { padding: 0.5rem 0.8rem; font-size: 1.3rem; }
}

.nav-toggle {
  display: none;
  width: 42px; height: 42px;
  border-radius: var(--radius-sm);
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-fine-strong);
}
.nav-toggle span {
  display: block;
  width: 18px; height: 2px;
  background: var(--c-deep);
  position: relative;
  transition: transform var(--dur-fast) var(--ease-soft), opacity var(--dur-fast) var(--ease-soft);
}
.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px; height: 2px;
  background: var(--c-deep);
  transition: transform var(--dur-fast) var(--ease-soft), top var(--dur-fast) var(--ease-soft);
}
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }

@media (max-width: 900px) {
  .site-header__nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    bottom: 0;
    background: #fff;
    flex-direction: column;
    align-items: flex-start;
    padding: 2rem var(--gutter);
    gap: 0.5rem;
    transform: translateX(100%);
    transition: transform var(--dur-base) var(--ease-soft);
    overflow-y: auto;
  }
  .site-header__nav.is-open { transform: translateX(0); }
  .site-header__nav a { font-size: 1.3rem; padding: 0.75rem 0; width: 100%; }
  .nav-toggle { display: flex; }
  body.nav-is-open { overflow: hidden; }
  /* Bug connu sur mobile : une vidéo <video> peut s'afficher dans un calque
     matériel qui ignore le z-index et passe au-dessus de tout, y compris le
     menu. On la masque simplement tant que le menu est ouvert. */
  body.nav-is-open .hero__media { visibility: hidden; }
  /* Pas de backdrop-filter ici : sur un ancêtre d'un élément position:fixed,
     ça crée un "containing block" qui casse le plein écran du menu mobile
     (bottom:0 se cale sur le header au lieu du viewport). Fond opaque à la place. */
  .site-header,
  .site-header.is-scrolled,
  body:not(.is-home) .site-header {
    background: #ffffff;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border-bottom: 1px solid var(--border-fine);
  }
}