:root {
  --primary-color: #0f172a;
  --accent-color: #2563eb;
  --accent-hover: #1d4ed8;
  --bg-main: #f8fafc;
  --card-bg: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --border-color: #e2e8f0;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 24px -4px rgba(0,0,0,0.12);
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', system-ui, -apple-system, Roboto, sans-serif;
}

body {
  background-color: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.6;
}

/* ===== BARRA DE PROGRESO DE LECTURA ===== */
#progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  background: linear-gradient(90deg, #2563eb, #3b82f6);
  width: 0%;
  z-index: 2000;
  transition: width 0.1s ease-out;
}

/* ===== NAVBAR ===== */
/* ===== HEADER MEJORADO Y DINÁMICO ===== */
header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid var(--border-color);
  /* Transición suave para ocultar/mostrar */
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1), background-color 0.3s ease;
}

/* Oculta la barra deslizándola hacia arriba */
.header-hidden {
  transform: translateY(-100%);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--primary-color);
}

.logo img {
  height: 38px;
  width: auto;
}

nav ul {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 24px;
}

nav ul li a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
}

nav ul li a:hover, nav ul li a.active {
  color: var(--accent-color);
}

.btn-login-nav {
  background: var(--primary-color);
  color: white !important;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
}

.btn-login-nav:hover {
  background: var(--accent-color);
}

.menu-toggle {
  display: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: var(--primary-color);
}

/* ===== LAYOUT & CONTENEDOR PRINCIPAL ===== */
.wrapper {
  margin-top: 80px;
  padding-bottom: 60px;
}

.contenedor-donaciones {
  max-width: 860px;
  margin: 20px auto 0;
  display: flex;
  justify-content: flex-end;
  padding: 0 16px;
}

.btn-donaciones {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #ef4444;
  color: white;
  text-decoration: none;
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.btn-donaciones:hover {
  background: #dc2626;
  transform: translateY(-2px);
}

.principal {
  max-width: 860px;
  background: var(--card-bg);
  margin: 16px auto;
  padding: 48px 56px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color);
}

/* ===== CABECERA DE ARTÍCULO ===== */
.articulo-header {
  position: relative;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 24px;
  margin-bottom: 32px;
}

.meta-badge {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.categoria-encabezado {
  background: #eff6ff;
  color: var(--accent-color);
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 12px;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.5px;
}

.principal h2 {
  font-size: 2.2rem;
  color: var(--primary-color);
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -0.02em;
}

/* Menu de Acciones Flotante */
.acciones-container {
  position: absolute;
  top: 0;
  right: 0;
}

.btn-opciones {
  width: 40px;
  height: 40px;
  border: 1px solid var(--border-color);
  border-radius: 50%;
  background: white;
  color: var(--text-secondary);
  font-size: 1.1rem;
  cursor: pointer;
  transition: var(--transition);
}

.btn-opciones:hover {
  background: var(--bg-main);
  color: var(--primary-color);
}

.popup-acciones {
  position: absolute;
  top: 48px;
  right: 0;
  background: white;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  display: none;
  flex-direction: column;
  min-width: 200px;
  z-index: 100;
  overflow: hidden;
}

.popup-acciones.activo {
  display: flex;
}

.btn-action {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  font-size: 0.9rem;
  border: none;
  background: transparent;
  color: var(--text-primary);
  text-decoration: none;
  cursor: pointer;
  text-align: left;
  transition: var(--transition);
}

.btn-action:hover {
  background: var(--bg-main);
}

/* ===== CUERPO DE ARTÍCULO ===== */
.articulo-body p {
  font-size: 1.1rem;
  color: #334155;
  margin-bottom: 20px;
  line-height: 1.8;
}

.articulo-body p.lead {
  font-size: 1.25rem;
  color: var(--primary-color);
  font-weight: 400;
}

.articulo-body h3 {
  font-size: 1.4rem;
  color: var(--primary-color);
  margin: 36px 0 18px;
  font-weight: 700;
}

/* Tarjetas Tríada CIA (Grid Visual) */
.cia-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 24px 0 32px;
}

.cia-card {
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 20px;
  transition: var(--transition);
}

.cia-card:hover {
  border-color: var(--accent-color);
  transform: translateY(-2px);
}

.cia-icon {
  font-size: 1.4rem;
  color: var(--accent-color);
  margin-bottom: 12px;
}

.cia-card h4 {
  font-size: 1rem;
  color: var(--primary-color);
  margin-bottom: 8px;
}

.cia-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 0;
}

/* Accordion */
.referencias-section {
  margin-top: 40px;
  border-top: 1px solid var(--border-color);
  padding-top: 24px;
}

.accordion {
  width: 100%;
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--primary-color);
  cursor: pointer;
  transition: var(--transition);
}

.accordion:hover {
  background: #e2e8f0;
}

.accordion .arrow {
  transition: transform 0.3s ease;
}

.accordion.active .arrow {
  transform: rotate(180deg);
}

.panel {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
  background: white;
}

.ref-list {
  padding: 16px;
  list-style: none;
}

.ref-list li {
  margin-bottom: 10px;
  font-size: 0.9rem;
}

.ref-list a {
  color: var(--accent-color);
  text-decoration: none;
}

/* ===== ARTÍCULOS RELACIONADOS ===== */
.articulos {
  max-width: 1100px;
  margin: 60px auto 0;
  padding: 0 20px;
}

.articulos h2 {
  font-size: 1.6rem;
  color: var(--primary-color);
  margin-bottom: 24px;
  text-align: center;
}

.grid-articulos {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.card-articulo {
  background: white;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.card-articulo:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.card-img-wrapper {
  position: relative;
  height: 180px;
}

.card-img-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-badge {
  position: absolute;
  top: 12px;
  left: 12px;
  background: rgba(15, 23, 42, 0.8);
  color: white;
  padding: 4px 10px;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  backdrop-filter: blur(4px);
}

.card-contenido {
  padding: 20px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.card-contenido h3 {
  font-size: 1.1rem;
  color: var(--primary-color);
  margin-bottom: 10px;
  line-height: 1.4;
}

.card-contenido p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  flex: 1;
  margin-bottom: 16px;
}

.btn-leer {
  color: var(--accent-color);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}

.btn-leer:hover {
  gap: 10px;
}

/* ===== FOOTER ===== */
.footer {
  background: var(--primary-color);
  color: #94a3b8;
  padding: 32px 20px;
  margin-top: 60px;
  text-align: center;
  font-size: 0.9rem;
}

.footer a {
  color: white;
  text-decoration: none;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 860px) {
  .principal {
    width: 92%;
    padding: 32px 24px;
  }
  
  .cia-grid {
    grid-template-columns: 1fr;
  }

  .grid-articulos {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 680px) {
  .menu-toggle {
    display: block;
  }

  nav ul {
    position: absolute;
    top: 60px;
    left: 0;
    width: 100%;
    background: white;
    flex-direction: column;
    padding: 20px 0;
    border-bottom: 1px solid var(--border-color);
    display: none;
  }

  nav ul.actives {
    display: flex;
  }

  .grid-articulos {
    grid-template-columns: 1fr;
  }
}