/* ============================================================
   LAYOUT — Header, Footer, Navigation, Grilles de page
   ============================================================ */

/* ===== HEADER ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.50);
  box-shadow: 0 1px 24px rgba(26, 61, 110, 0.08);
  z-index: var(--z-sticky);
  transition: background var(--t-base), box-shadow var(--t-base);
}
.site-header.scrolled {
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 4px 32px rgba(26, 61, 110, 0.14);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

/* Logo */
.header-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}
.header-logo:hover { text-decoration: none; }

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--gradient-hero);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: var(--text-lg);
  font-weight: var(--fw-bold);
  font-family: var(--font-heading);
  flex-shrink: 0;
}
.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}
.logo-text .logo-main {
  font-family: var(--font-heading);
  font-weight: var(--fw-bold);
  font-size: var(--text-base);
  color: var(--primary-dark);
}
.logo-text .logo-sub {
  font-size: var(--text-xs);
  color: var(--text-muted);
  font-weight: var(--fw-medium);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* Navigation principale */
.header-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: var(--fw-medium);
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--t-fast);
  white-space: nowrap;
}
.nav-link:hover, .nav-link.active {
  background-color: var(--primary-100);
  color: var(--primary-color);
  text-decoration: none;
}
.nav-link.active { font-weight: var(--fw-semibold); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Bouton hamburger mobile */
.btn-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  border-radius: var(--radius-md);
  transition: background var(--t-fast);
}
.btn-hamburger:hover { background: var(--bg-surface); }
.btn-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 2px;
  transition: all var(--t-base);
}
.btn-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.btn-hamburger.open span:nth-child(2) { opacity: 0; }
.btn-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Drawer mobile */
.mobile-menu {
  display: flex;               /* toujours flex pour que les transitions fonctionnent */
  flex-direction: column;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(17, 42, 74, 0.82);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid rgba(255, 255, 255, 0.10);
  z-index: var(--z-overlay);
  padding: 24px;
  gap: 8px;
  overflow-y: auto;
  /* Animation via visibility + opacity (display ne peut pas être animé) */
  visibility: hidden;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-8px);
  transition: opacity var(--t-base), transform var(--t-base),
              visibility 0s linear var(--t-base);
}
.mobile-menu.open {
  visibility: visible;
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
  transition: opacity var(--t-base), transform var(--t-base),
              visibility 0s linear 0s;
}
.mobile-menu .nav-link {
  padding: 14px 16px;
  font-size: var(--text-base);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 0;
  color: rgba(255, 255, 255, 0.85);
}
.mobile-menu .nav-link:hover,
.mobile-menu .nav-link.active {
  color: white;
  background: rgba(255, 255, 255, 0.12);
  border-color: transparent;
}

/* ===== BARRE DE NAVIGATION DES SECTIONS ===== */
.nav-sections {
  position: sticky;
  top: var(--header-height);
  z-index: calc(var(--z-sticky) - 10);
  background: var(--bg-nav);
  border-bottom: 1px solid var(--border-light);
  box-shadow: var(--shadow-xs);
}
.nav-sections-inner {
  display: flex;
  align-items: center;
  gap: 0;
  overflow-x: auto;
  scrollbar-width: none;
}
.nav-sections-inner::-webkit-scrollbar { display: none; }
.nav-section-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 20px;
  font-size: var(--text-sm);
  font-weight: var(--fw-medium);
  color: var(--text-secondary);
  text-decoration: none;
  border-bottom: 3px solid transparent;
  white-space: nowrap;
  transition: all var(--t-fast);
}
.nav-section-link:hover {
  color: var(--primary-color);
  background: var(--primary-100);
  text-decoration: none;
}
.nav-section-link.active {
  color: var(--primary-color);
  border-bottom-color: var(--primary-color);
  font-weight: var(--fw-semibold);
}
.nav-section-link .section-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  background: var(--primary-100);
  color: var(--primary-color);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--fw-bold);
}
.nav-section-link.active .section-num {
  background: var(--primary-color);
  color: white;
}

/* ===== LAYOUT PRINCIPAL ===== */
.page-main {
  padding-top: var(--header-height);
  min-height: 100vh;
}
.page-main.with-section-nav { padding-top: calc(var(--header-height) + 49px); }

/* Grille 2 colonnes avec sidebar */
.layout-with-sidebar {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 32px;
  align-items: start;
}

/* ===== SECTION BLOCK ===== */
.section-block {
  padding: var(--section-py) 0;
}
.section-block + .section-block {
  border-top: 1px solid var(--border-light);
}
.section-block.alt-bg {
  background: var(--bg-section-alt);
}

.section-header {
  margin-bottom: 48px;
}
.section-header .section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--primary-100);
  color: var(--primary-color);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--fw-semibold);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 16px;
}
.section-header h2 {
  color: var(--primary-dark);
  margin-bottom: 12px;
}
.section-header p {
  font-size: var(--text-lg);
  max-width: 680px;
}

/* Séparateur décoratif sous titre */
.section-divider {
  width: 60px;
  height: 4px;
  background: var(--gradient-section-header);
  border-radius: var(--radius-full);
  margin: 16px 0 24px;
}

/* ===== GRILLES ===== */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }

@media (max-width: 1023px) {
  .grid-4    { grid-template-columns: repeat(2, 1fr); }
  .layout-with-sidebar { grid-template-columns: 1fr; }
  .layout-sidebar { display: none; }
}
@media (max-width: 767px) {
  .grid-3    { grid-template-columns: 1fr; }
  .grid-4    { grid-template-columns: 1fr; }
  .grid-2    { grid-template-columns: 1fr; }
  .section-block { padding: 48px 0; }
  .section-header { margin-bottom: 32px; }
  .header-nav { display: none; }
  .btn-hamburger { display: flex; }
}

/* ===== SIDEBAR FIXE (sur pages de section) ===== */
.layout-sidebar {
  position: sticky;
  top: calc(var(--header-height) + 49px + 24px);
}
.sidebar-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 20px;
  margin-bottom: 20px;
}
.sidebar-card h3 {
  font-size: var(--text-sm);
  font-weight: var(--fw-semibold);
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-light);
}
.sidebar-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 10px;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--t-fast);
}
.sidebar-link:hover {
  background: var(--primary-100);
  color: var(--primary-color);
  text-decoration: none;
}
.sidebar-link.active {
  background: var(--primary-100);
  color: var(--primary-color);
  font-weight: var(--fw-medium);
}

/* ===== FOOTER ===== */
.site-footer {
  background: var(--primary-dark);
  color: rgba(255,255,255,0.8);
  padding: 48px 0 24px;
  margin-top: 80px;
}
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-brand .logo-main   { color: white; font-size: var(--text-lg); }
.footer-brand .logo-sub    { color: rgba(255,255,255,0.6); }
.footer-brand p {
  color: rgba(255,255,255,0.65);
  font-size: var(--text-sm);
  margin-top: 12px;
  line-height: var(--lh-relaxed);
}
.footer-col h4 {
  color: white;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}
.footer-col ul { list-style: none; padding: 0; }
.footer-col ul li + li { margin-top: 8px; }
.footer-col ul li a {
  color: rgba(255,255,255,0.65);
  font-size: var(--text-sm);
  transition: color var(--t-fast);
}
.footer-col ul li a:hover { color: white; text-decoration: none; }

.footer-bottom {
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.45);
}
.footer-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-full);
  padding: 4px 12px;
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.7);
}

@media (max-width: 767px) {
  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
}

/* ===== BARRE DE PROGRESSION DE LECTURE ===== */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--gradient-section-header);
  z-index: calc(var(--z-sticky) + 10);
  transition: width var(--t-fast);
  pointer-events: none;
}