/* ==========================================================================
   HEADER / NAVBAR + SIDEBAR
   ========================================================================== */

.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-height);
  display: flex;
  align-items: center;
  z-index: var(--z-header);
  background: linear-gradient(90deg, rgba(11,36,71,0.95) 0%, rgba(25,55,109,0.92) 100%);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  transition: background var(--dur-base) var(--ease-elegant), box-shadow var(--dur-base) var(--ease-elegant);
}
.site-header.is-scrolled {
  background: linear-gradient(90deg, var(--color-navy-900) 0%, var(--color-navy-700) 100%);
  box-shadow: var(--shadow-md);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

/* ---- Logo (solo imagen, ya contiene texto) ---- */
.brand {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}
.brand img {
  height: 48px;
  width: auto;
  border-radius: 4px;
  object-fit: contain;
}

/* ---- Menú horizontal (desktop) ---- */
.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  flex: 1;
  justify-content: center;
}
.nav-menu a {
  color: var(--text-on-dark-soft);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  letter-spacing: 0.02em;
  position: relative;
  padding: var(--space-2) 0;
  transition: color var(--dur-fast) var(--ease-elegant);
  white-space: nowrap;
}
.nav-menu a::after {
  content: '';
  position: absolute;
  left: 0; bottom: -2px;
  width: 0; height: 2px;
  background: var(--color-gold-500);
  transition: width var(--dur-base) var(--ease-elegant);
}
.nav-menu a:hover,
.nav-menu a.is-active { color: var(--color-white); }
.nav-menu a:hover::after,
.nav-menu a.is-active::after { width: 100%; }

/* ---- Botones de sesión (desktop) ---- */
.header-session {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}
.btn-session {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-on-dark-soft);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.02em;
  padding: 0.5rem 0.9rem;
  border-radius: var(--radius-sm);
  transition: color var(--dur-fast), background var(--dur-fast);
  white-space: nowrap;
}
.btn-session svg { width: 16px; height: 16px; flex-shrink: 0; }
.btn-session:hover { color: var(--color-white); background: rgba(255,255,255,0.08); }
.btn-session-register {
  border: 1.5px solid rgba(255,255,255,0.3);
  border-radius: var(--radius-full);
}
.btn-session-register:hover {
  border-color: var(--color-gold-500);
  color: var(--color-gold-500);
}

/* ---- Hamburguesa ---- */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  width: 28px;
  height: 22px;
  position: relative;
  z-index: calc(var(--z-header) + 5);
  flex-shrink: 0;
}
.nav-toggle span {
  position: absolute;
  left: 0; right: 0;
  height: 2px;
  background: var(--color-white);
  transition: transform var(--dur-base) var(--ease-elegant), opacity var(--dur-base);
}
.nav-toggle span:nth-child(1) { top: 0; }
.nav-toggle span:nth-child(2) { top: 10px; }
.nav-toggle span:nth-child(3) { top: 20px; }
.nav-toggle.is-open span:nth-child(1) { transform: translateY(10px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-10px) rotate(-45deg); }

/* ==========================================================================
   SIDEBAR LATERAL (solo móvil)
   ========================================================================== */

.sidebar-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  z-index: var(--z-overlay);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-base) var(--ease-elegant), visibility var(--dur-base);
}
.sidebar-overlay.is-visible {
  opacity: 1;
  visibility: visible;
}

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: 280px;
  height: 100vh;
  height: 100dvh;
  background: var(--color-navy-900);
  z-index: var(--z-modal);
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform var(--dur-base) var(--ease-elegant);
  box-shadow: var(--shadow-lg);
  overflow-y: auto;
}
.sidebar.is-open {
  transform: translateX(0);
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-5) var(--space-5) var(--space-4);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.sidebar-header .brand img { height: 40px; }

.sidebar-close {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.08);
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background var(--dur-fast);
}
.sidebar-close:hover { background: rgba(255,255,255,0.15); }
.sidebar-close svg { width: 18px; height: 18px; color: var(--color-white); }

.sidebar-nav {
  flex: 1;
  padding: var(--space-3) 0;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  color: var(--text-on-dark-soft);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  letter-spacing: 0.01em;
  transition: background var(--dur-fast), color var(--dur-fast);
  border-left: 3px solid transparent;
}
.sidebar-link:hover {
  background: rgba(255,255,255,0.06);
  color: var(--color-white);
}
.sidebar-link.is-active {
  background: rgba(25,55,109,0.5);
  color: var(--color-white);
  border-left-color: var(--color-gold-500);
}
.sidebar-link svg {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  opacity: 0.7;
}
.sidebar-link.is-active svg,
.sidebar-link:hover svg { opacity: 1; }

.sidebar-footer {
  padding: 0 0 var(--space-5);
}
.sidebar-divider {
  height: 1px;
  background: rgba(255,255,255,0.08);
  margin: var(--space-2) var(--space-5) var(--space-3);
}
.sidebar-session {
  color: var(--text-on-dark-soft);
}
.sidebar-session:hover {
  color: var(--color-gold-500);
}

/* ==========================================================================
   RESPONSIVE
   ========================================================================== */
@media (min-width: 961px) {
  .sidebar,
  .sidebar-overlay { display: none !important; }
  .nav-toggle { display: none !important; }
}

@media (max-width: 960px) {
  .nav-menu { display: none; }
  .header-session { display: none; }
  .nav-toggle { display: block; }
  .brand img { height: 38px; }
}

@media (max-width: 480px) {
  .brand img { height: 32px; }
}