/* ============================================================
   HEADER — Site header, navigation, hamburger menu
   Root class: header (element selector — the only instance)
   ============================================================ */

/* ── Header bar ─────────────────────────────────────────────────────── */

header {
  vertical-align: center;
  flex-shrink: 0;
  background: linear-gradient(
    180deg,
    var(--gradient-1) 0%,
    var(--gradient-2) 33%,
    var(--gradient-3) 66%,
    var(--gradient-4) 100%
  );
}

/* ── Navigation ────────────────────────────────────────────────────── */

header nav {
  padding: var(--space-s) var(--space-s);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: var(--step-0);
}

header nav ul {
  display: flex;
  gap: var(--space-l);
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
}

header nav ul a {
  font-family: var(--font-display);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-foreground);
  text-decoration: none;
  padding: var(--space-3xs) var(--space-xs);
  border-radius: var(--radius);
  text-shadow:
    0 0 16px var(--header-shadow-strong),
    0 0 32px var(--header-shadow-soft);
  transition: opacity 0.15s;
}

header nav ul a:hover {
  color: var(--accent-primary);
}

header nav ul a[aria-current="page"] {
  opacity: 1;
  border-bottom: 1px solid var(--header-nav-active-border);
  padding-bottom: 1px;
  color: var(--accent-foreground);
}

/* ── Logo ───────────────────────────────────────────────────────────── */

.nav-logo {
  text-decoration: none;
}

.nav-left-links,
.nav-right-links {
  display: flex;
  gap: var(--space-l);
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-top-row {
  display: contents;
}

.nav-mobile-links {
  display: none;
}

/* ── Hamburger menu (pure CSS, checkbox trick) ──────────────────────── */
/* DOM order (public only):
     input.menu-btn            ← off-screen checkbox
     nav
       div.nav-top-row         ← always-visible row
         ul.nav-left-links     ← logo + Répertoire
         ul.nav-right-links    ← Licences, À Propos
         label.menu-icon       ← burger icon trigger
       ul.nav-mobile-links     ← full dropdown (hidden by default) */

.menu-btn {
  position: absolute;
  top: -9999px;
  left: -9999px;
}

.menu-icon {
  display: none;
  cursor: pointer;
  padding: var(--space-2xs) var(--space-s);
  align-items: center;
  justify-content: center;
}

/* Middle bar of the burger icon */
.navicon {
  background: var(--accent-foreground);
  display: block;
  height: 2px;
  width: 24px;
  position: relative;
  transition: all 0.3s ease-out;
}

.navicon::before,
.navicon::after {
  content: "";
  background: var(--accent-foreground);
  display: block;
  height: 2px;
  width: 100%;
  position: absolute;
  transition: all 0.3s ease-out;
}

.navicon::before { top: -7px; }
.navicon::after  { bottom: -7px; }

/* ── Mobile (≤ 640px) ───────────────────────────────────────────────── */

@media screen and (max-width: 640px) {
  header nav[aria-label="Navigation principale"] {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    padding: 0;
  }

  header nav[aria-label="Navigation principale"] .nav-top-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-s);
  }

  header nav[aria-label="Navigation principale"] .nav-right-links {
    display: none;
  }

  header nav[aria-label="Navigation principale"] .nav-left-links {
    display: flex;
    gap: 0;
  }

  header nav[aria-label="Navigation principale"]
    .nav-left-links li:not(:first-child) {
    display: none;
  }

  .menu-icon { display: flex; }

  header nav[aria-label="Navigation principale"] .nav-mobile-links {
    display: block;
    list-style: none;
    margin: 0;
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.2s ease-out;
  }

  .menu-btn:checked
    ~ nav[aria-label="Navigation principale"]
    .nav-mobile-links {
    max-height: 300px;
  }

  header nav[aria-label="Navigation principale"] .nav-mobile-links li {
    border-top: 1px solid var(--header-nav-active-border);
    text-align: left;
  }

  header nav[aria-label="Navigation principale"] .nav-mobile-links li a {
    display: block;
    width: 100%;
    padding: var(--space-s) var(--space-s);
    text-align: left;
  }

  /* Animate burger → X */
  .menu-btn:checked
    ~ nav[aria-label="Navigation principale"]
    .menu-icon
    .navicon {
    background: transparent;
  }

  .menu-btn:checked
    ~ nav[aria-label="Navigation principale"]
    .menu-icon
    .navicon::before {
    transform: rotate(-45deg);
    top: 0;
  }

  .menu-btn:checked
    ~ nav[aria-label="Navigation principale"]
    .menu-icon
    .navicon::after {
    transform: rotate(45deg);
    bottom: 0;
  }
}