:root {
  --azul-900: #1e3a8a;
  --azul-800: #1e40af;
  --azul-700: #1d4ed8;
  --azul-600: #2563eb;
  --azul-100: #dbeafe;
  --azul-50: #eff6ff;
  --acento: #f59e0b;
  --acento-oscuro: #b45309;
  --gris-900: #111827;
  --gris-700: #374151;
  --gris-500: #6b7280;
  --gris-200: #e5e7eb;
  --gris-100: #f3f4f6;
  --gris-50: #f9fafb;
  --blanco: #ffffff;
  --radio: 14px;
  --sombra: 0 1px 2px rgba(17, 24, 39, 0.04), 0 2px 6px rgba(17, 24, 39, 0.06);
  --sombra-md: 0 2px 4px rgba(17, 24, 39, 0.05), 0 8px 16px rgba(17, 24, 39, 0.08);
  --sombra-hover: 0 8px 12px rgba(17, 24, 39, 0.07), 0 16px 32px rgba(30, 64, 175, 0.14);
  --font-heading: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--gris-900);
  background: var(--blanco);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4,
.acordeon__titulo,
.exam-card__badge,
.site-header__brand h1,
.site-footer h3 {
  font-family: var(--font-heading);
  letter-spacing: -0.01em;
}

a { color: var(--azul-700); }

.hidden { display: none !important; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Header */
.site-header {
  background: linear-gradient(150deg, var(--azul-900) 0%, var(--azul-800) 45%, var(--azul-600) 100%);
  color: var(--blanco);
  padding: 1.4rem 1rem;
}

.site-header__inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  justify-content: space-between;
}

.site-header__brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  min-width: 0;
}

.site-header__brand img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--blanco);
  padding: 4px;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.18);
}

.site-header__brand h1 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0;
  line-height: 1.25;
}

.site-header__brand p {
  margin: 0.15rem 0 0;
  font-size: 0.8rem;
  color: var(--azul-100);
}

.buscador {
  flex: 1 1 260px;
  max-width: 420px;
}

.buscador input {
  width: 100%;
  padding: 0.65rem 0.95rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 0.95rem;
  background: rgba(255, 255, 255, 0.95);
  transition: box-shadow 200ms var(--ease-out), background-color 200ms var(--ease-out);
}

.buscador input:focus {
  outline: none;
  background: var(--blanco);
  box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.55);
}

/* Nav */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--gris-200);
  box-shadow: var(--sombra);
}

.site-nav__inner {
  position: relative;
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  gap: 0.25rem;
  padding: 0 1rem;
  overflow-x: auto;
}

.site-nav__indicador {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: var(--azul-600);
  border-radius: 3px 3px 0 0;
  transition: transform 320ms var(--ease-out), width 320ms var(--ease-out);
}

.site-nav__link {
  display: block;
  padding: 0.85rem 1rem;
  white-space: nowrap;
  text-decoration: none;
  color: var(--gris-700);
  font-weight: 600;
  font-size: 0.92rem;
  border-radius: 8px 8px 0 0;
  transition: color 200ms var(--ease-out), background-color 200ms var(--ease-out);
}

.site-nav__link:hover {
  color: var(--azul-700);
  background: var(--azul-50);
}

.site-nav__link.activo {
  color: var(--azul-700);
  font-weight: 700;
}

/* Layout */
main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
}

.section { margin-bottom: 3rem; scroll-margin-top: 4.5rem; }

.section-panel,
.section-muted {
  padding: 1.75rem 1.25rem;
  border-radius: 20px;
}

.section-panel {
  background: linear-gradient(180deg, var(--azul-50) 0%, rgba(239, 246, 255, 0.35) 100%);
}

.section-muted {
  background: var(--gris-50);
}

.section-titulo {
  font-size: 1.65rem;
  font-weight: 800;
  margin: 0 0 0.35rem;
  color: var(--azul-900);
}

.section-subtitulo {
  margin: 0 0 1.25rem;
  color: var(--gris-500);
  font-size: 0.95rem;
}

.sin-resultados {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  padding: 2.5rem 1rem;
  text-align: center;
  color: var(--gris-500);
}

.sin-resultados__icono {
  width: 40px;
  height: 40px;
  color: var(--gris-200);
}

.sin-resultados p {
  margin: 0;
  font-size: 0.95rem;
}

/* Certamenes */
.exam-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

.exam-card {
  background: var(--blanco);
  border: 1px solid var(--gris-200);
  border-top: 4px solid var(--azul-600);
  border-radius: var(--radio);
  padding: 1.25rem;
  box-shadow: var(--sombra-md);
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  transition: opacity 450ms var(--ease-out), transform 250ms var(--ease-out), box-shadow 250ms var(--ease-out);
}

.exam-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--sombra-hover);
}

.exam-card__badge {
  display: inline-block;
  background: var(--acento);
  color: var(--blanco);
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  width: fit-content;
}

.exam-card h3 {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gris-900);
}

.exam-card__cobertura {
  margin: 0;
  font-size: 0.88rem;
  color: var(--gris-500);
}

.exam-card__grupo h4 {
  margin: 0 0 0.4rem;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--azul-700);
}

.taller-block {
  margin-top: 1.25rem;
  background: var(--azul-50);
  border: 1px solid var(--azul-100);
  border-radius: var(--radio);
  padding: 1.1rem 1.25rem;
  transition: opacity 450ms var(--ease-out), transform 250ms var(--ease-out), box-shadow 250ms var(--ease-out);
}

.taller-block:hover {
  box-shadow: var(--sombra-md);
}

.taller-block h3 {
  margin: 0 0 0.75rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--azul-900);
}

/* Lista de archivos */
.lista-archivos {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.archivo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--gris-50);
  border: 1px solid var(--gris-200);
  border-radius: 8px;
  padding: 0.55rem 0.7rem;
  transition: opacity 450ms var(--ease-out), transform 220ms var(--ease-out), box-shadow 220ms var(--ease-out), background-color 220ms var(--ease-out), border-color 220ms var(--ease-out);
}

.archivo:hover {
  background: var(--blanco);
  border-color: var(--azul-100);
  box-shadow: var(--sombra-md);
  transform: translateY(-1px);
}

.archivo__icono {
  flex-shrink: 0;
  width: 30px;
  height: 30px;
  border-radius: 6px;
  background: var(--azul-100);
  color: var(--azul-800);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.68rem;
  font-weight: 700;
}

.archivo__nombre {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 0.9rem;
  color: var(--gris-900);
  overflow-wrap: anywhere;
}

.archivo__acciones {
  display: flex;
  gap: 0.35rem;
  flex-shrink: 0;
}

.btn {
  border: none;
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.4rem 0.65rem;
  border-radius: 7px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  white-space: nowrap;
  position: relative;
  transition: transform 180ms var(--ease-out), box-shadow 180ms var(--ease-out), background-color 180ms var(--ease-out), color 180ms var(--ease-out), opacity 180ms var(--ease-out);
}

.btn-ver {
  background: var(--azul-600);
  color: var(--blanco);
}
.btn-ver:hover {
  background: var(--azul-700);
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.35);
  transform: translateY(-1px) scale(1.03);
}
.btn-ver:active {
  transform: scale(0.96);
  box-shadow: none;
}

.btn-descargar {
  background: var(--gris-100);
  color: var(--gris-700);
  border: 1px solid var(--gris-200);
}
.btn-descargar:hover {
  background: var(--gris-200);
  transform: translateY(-1px) scale(1.03);
  box-shadow: var(--sombra);
}
.btn-descargar:active {
  transform: scale(0.96);
}

.btn.cargando {
  color: transparent !important;
  pointer-events: none;
}
.btn.cargando::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 14px;
  height: 14px;
  margin: -7px 0 0 -7px;
  border: 2px solid rgba(37, 99, 235, 0.25);
  border-top-color: var(--azul-600);
  border-radius: 50%;
  animation: girar 600ms linear infinite;
}

@keyframes girar {
  to { transform: rotate(360deg); }
}

/* Acordeones (Unidades y Complementario) */
.acordeon {
  background: var(--blanco);
  border: 1px solid var(--gris-200);
  border-radius: var(--radio);
  margin-bottom: 0.85rem;
  box-shadow: var(--sombra);
  transition: opacity 450ms var(--ease-out), transform 250ms var(--ease-out), box-shadow 250ms var(--ease-out);
}

.acordeon:hover {
  box-shadow: var(--sombra-md);
}

.acordeon__cabecera {
  width: 100%;
  cursor: pointer;
  border: none;
  background: transparent;
  font-family: var(--font-heading);
  padding: 0.9rem 1.1rem;
  font-weight: 700;
  font-size: 1rem;
  color: var(--azul-900);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  border-radius: var(--radio);
  transition: background-color 180ms var(--ease-out);
}

.acordeon__cabecera:hover { background: var(--azul-50); }

.acordeon__icono {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  color: var(--azul-600);
  transition: transform 200ms var(--ease-out);
}

.acordeon__icono svg { width: 100%; height: 100%; }

.acordeon.abierto .acordeon__icono { transform: rotate(90deg); }

.acordeon__panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 320ms var(--ease-out);
}

.acordeon.abierto .acordeon__panel { grid-template-rows: 1fr; }

.acordeon__panel-inner {
  overflow: hidden;
  min-height: 0;
}

.acordeon__panel-inner > * {
  padding: 0 1.1rem 1.1rem;
}

/* Complementario */
.section-muted .section-titulo { color: var(--gris-700); }

.complementario-panel {
  border: 1px dashed var(--gris-200);
}

.profesor-bloque {
  margin-top: 1rem;
  transition: opacity 450ms var(--ease-out), transform 220ms var(--ease-out);
}

.profesor-bloque:first-child { margin-top: 0; }

.profesor-bloque h4 {
  margin: 0 0 0.6rem;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--gris-700);
}

/* Animaciones de entrada (scroll reveal) */
.reveal {
  opacity: 0;
  transform: translateY(16px);
}

.reveal--visible {
  opacity: 1;
  transform: translateY(0);
}

/* Footer */
.site-footer {
  background: linear-gradient(160deg, var(--gris-900) 0%, #0b1220 100%);
  color: var(--gris-200);
  padding: 2.25rem 1rem;
}

.site-footer__inner {
  max-width: 1100px;
  margin: 0 auto;
}

.site-footer h3 {
  margin: 0 0 1rem;
  color: var(--blanco);
  font-size: 1.1rem;
  font-weight: 700;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.footer-links a {
  color: var(--azul-100);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 0.5rem 0.8rem;
  border-radius: 8px;
  font-size: 0.85rem;
  text-decoration: none;
  transition: background-color 200ms var(--ease-out), transform 200ms var(--ease-out), border-color 200ms var(--ease-out);
}

.footer-links a:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-1px);
}
.footer-links a:active { transform: scale(0.97); }

.site-footer__nota {
  margin-top: 1.5rem;
  font-size: 0.78rem;
  color: var(--gris-500);
}

/* Modal visor PDF */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 250ms var(--ease-out), visibility 0ms linear 250ms;
}

.modal-overlay.abierto {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition: opacity 250ms var(--ease-out), visibility 0ms linear 0ms;
}

.modal {
  background: var(--blanco);
  width: 100%;
  max-width: 960px;
  height: 90vh;
  border-radius: var(--radio);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.35);
  transform: scale(0.94) translateY(10px);
  opacity: 0;
  transition: transform 280ms var(--ease-out), opacity 250ms var(--ease-out);
}

.modal-overlay.abierto .modal {
  transform: scale(1) translateY(0);
  opacity: 1;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.8rem 1.1rem;
  background: linear-gradient(120deg, var(--azul-800), var(--azul-600));
  color: var(--blanco);
}

.modal-header__titulo {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.92rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
}

.modal-actions {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
}

.modal-actions .btn-descargar {
  background: rgba(255, 255, 255, 0.14);
  color: var(--blanco);
  border: 1px solid rgba(255, 255, 255, 0.28);
}
.modal-actions .btn-descargar:hover {
  background: rgba(255, 255, 255, 0.26);
  box-shadow: none;
}

.modal-actions .btn-cerrar {
  background: transparent;
  color: rgba(255, 255, 255, 0.8);
  font-size: 1.05rem;
  padding: 0.35rem 0.6rem;
}
.modal-actions .btn-cerrar:hover {
  color: var(--blanco);
  background: rgba(255, 255, 255, 0.16);
  transform: scale(1.05);
}
.modal-actions .btn-cerrar:active { transform: scale(0.94); }

.modal-body {
  position: relative;
  flex: 1 1 auto;
  display: flex;
}

.modal iframe {
  flex: 1 1 auto;
  width: 100%;
  border: none;
  background: var(--gris-100);
}

.modal-loader {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gris-100);
  transition: opacity 200ms var(--ease-out), visibility 0ms linear 0ms;
}

.modal-loader.oculto {
  opacity: 0;
  visibility: hidden;
  transition: opacity 200ms var(--ease-out), visibility 0ms linear 200ms;
}

.spinner {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 3px solid var(--azul-100);
  border-top-color: var(--azul-600);
  animation: girar 700ms linear infinite;
}

@media (max-width: 640px) {
  .modal { height: 95vh; border-radius: 0; }
  .archivo { flex-wrap: wrap; }
  .archivo__acciones { width: 100%; justify-content: flex-end; }
}