/* ======================================================
   RESET Y BASE GENERAL
====================================================== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  background-color: #000000;
  color: #ffffff;
  overflow-x: hidden;
}

/* ======================================================
   NAV INSTITUCIONAL (IDÉNTICO AL INDEX)
====================================================== */
.ob-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: #000000;
  border-bottom: 1px solid #c5a200;
  z-index: 1000;
}

.ob-nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* BRAND */
.ob-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.ob-brand-img {
  height: 90px;
  width: auto;
  max-width: 100%;
}

.ob-brand-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: #ffffff;
  letter-spacing: 0.4px;
}

/* BOTÓN MENÚ */
.ob-menu-btn {
  display: none;
  background: none;
  border: 1px solid #c5a200;
  color: #c5a200;
  padding: 0.45rem 0.75rem;
  font-size: 0.9rem;
  cursor: pointer;
}

.ob-menu-btn:focus {
  outline: 2px solid #c5a200;
  outline-offset: 2px;
}

/* MENÚ */
.ob-menu {
  display: flex;
  gap: 1.5rem;
}

.ob-menu a {
  color: #ffffff;
  text-decoration: none;
  font-size: 0.95rem;
  position: relative;
}

.ob-menu a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 1px;
  background-color: #c5a200;
  transition: width 0.25s ease;
}

.ob-menu a:hover::after,
.ob-menu a:focus::after {
  width: 100%;
}

/* BOTÓN CONTACTO */
.ob-contact-btn {
  margin-left: 1.5rem;
  padding: 0.45rem 0.9rem;
  border: 1px solid #c5a200;
  color: #c5a200;
  text-decoration: none;
  font-size: 0.9rem;
  transition: background-color 0.25s ease, color 0.25s ease;
}

.ob-contact-btn:hover,
.ob-contact-btn:focus {
  background-color: #c5a200;
  color: #000000;
}

/* ======================================================
   RESPONSIVE NAV
====================================================== */
@media (max-width: 900px) {
  .ob-menu-btn {
    display: inline-block;
  }

  .ob-contact-btn {
    display: none;
  }

  .ob-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: #000000;
    flex-direction: column;
    display: none;
    border-bottom: 1px solid #c5a200;
  }

  .ob-menu a {
    padding: 0.75rem 1rem;
    border-top: 1px solid #1a1a1a;
  }
}

/* ======================================================
   SECCIÓN ENCABEZADO — IDÉNTICA AL INDEX
====================================================== */
.ob-encabezado {
  position: relative;
  width: 100%;
  min-height: 70vh;
  margin-top: 84px;
  background-image: url("/img/biblioteca.png");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.ob-encabezado-overlay {
  position: absolute;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.55);
  z-index: 1;
}

.ob-encabezado-contenido {
  position: relative;
  z-index: 2;
  max-width: 1100px;
  padding: 2rem 1.5rem;
}

.ob-encabezado-contenido h1 {
  font-size: 2.4rem;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 1px;
  color: #ffffff;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.ob-encabezado-contenido p {
  font-size: 1rem;
  line-height: 1.6;
  color: #ffffff;
  max-width: 760px;
  margin: 0 auto;
}

.ob-encabezado-separador {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 6px;
  background-color: #c5a200;
  z-index: 2;
}

/* ======================================================
   RESPONSIVE ENCABEZADO
====================================================== */
@media (max-width: 900px) {
  .ob-encabezado {
    min-height: 60vh;
  }

  .ob-encabezado-contenido h1 {
    font-size: 1.8rem;
  }
}

@media (max-width: 480px) {
  .ob-encabezado {
    min-height: 55vh;
  }

  .ob-encabezado-contenido h1 {
    font-size: 1.5rem;
    line-height: 1.3;
  }

  .ob-encabezado-contenido p {
    font-size: 0.95rem;
  }
}

/* ======================================================
   ACCESIBILIDAD GLOBAL
====================================================== */
a:focus {
  outline: 2px solid #c5a200;
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto;
  }
}

/* ======================================================
   SECCIÓN BIBLIOTECA – GRID DE LIBROS
====================================================== */

.ob-biblioteca-libros {
  width: 100%;
  background-color: #000000;
  padding: 3.5rem 1rem;
}

.ob-biblioteca-title {
  text-align: center;
  font-size: 1.8rem;
  margin-bottom: 3rem;
  color: #ffffff;
  letter-spacing: 0.5px;
}

/* ------------------------------------------------------
   GRID 4 COLUMNAS
------------------------------------------------------ */
.ob-biblioteca-grid {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2.5rem;
  align-items: stretch;
}

/* ------------------------------------------------------
   ITEM LIBRO
------------------------------------------------------ */
.ob-biblioteca-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

/* IMAGEN (NO SE DEFORMA) */
.ob-biblioteca-img {
  width: 100%;
  max-width: 220px;
  height: 300px;              /* altura controlada */
  object-fit: contain;        /* nunca recorta ni deforma */
  margin-bottom: 1rem;
}

/* NOMBRE DEL LIBRO */
.ob-biblioteca-nombre {
  font-size: 1rem;
  margin-bottom: 1rem;
  color: #ffffff;
}

/* BOTÓN DESCARGAR */
.ob-biblioteca-btn {
  display: inline-block;
  padding: 0.55rem 1.4rem;
  border: 1px solid #c5a200;
  color: #c5a200;
  text-decoration: none;
  font-size: 0.9rem;
  transition: background-color 0.25s ease, color 0.25s ease;
}

.ob-biblioteca-btn:hover,
.ob-biblioteca-btn:focus {
  background-color: #c5a200;
  color: #000000;
}

/* ======================================================
   RESPONSIVE
====================================================== */
@media (max-width: 1024px) {
  .ob-biblioteca-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .ob-biblioteca-grid {
    grid-template-columns: 1fr;
  }

  .ob-biblioteca-img {
    height: 260px;
  }
}

/* ======================================================
   ACCESIBILIDAD
====================================================== */
.ob-biblioteca-btn:focus {
  outline: 2px solid #c5a200;
  outline-offset: 3px;
}

/* ======================================================
   SECCIÓN VISUALIZACIÓN PDF (RESPONSIVA)
====================================================== */

.ob-pdf {
  width: 100%;
  background-color: #000000;
  padding: 3.5rem 1rem;
  color: #ffffff;
}

.ob-pdf-title {
  text-align: center;
  font-size: 1.6rem;
  margin-bottom: 2rem;
  letter-spacing: 0.4px;
}

/* CONTENEDOR RESPONSIVO */
.ob-pdf-contenedor {
  max-width: 1280px;
  margin: 0 auto;
  position: relative;
  width: 100%;
  height: 80vh;            /* alto cómodo en desktop */
  border: 1px solid #c5a200;
}

/* IFRAME PDF */
.ob-pdf-contenedor iframe {
  width: 100%;
  height: 100%;
  border: 0;
  background-color: #000000;
}

/* ======================================================
   RESPONSIVE
====================================================== */
@media (max-width: 1024px) {
  .ob-pdf-contenedor {
    height: 70vh;
  }
}

@media (max-width: 600px) {
  .ob-pdf-contenedor {
    height: 65vh;          /* evita scroll excesivo en móvil */
  }
}

/* ======================================================
   ACCESIBILIDAD
====================================================== */
.ob-pdf-contenedor iframe:focus {
  outline: 2px solid #c5a200;
  outline-offset: 3px;
}
/* ======================================================
   FOOTER INSTITUCIONAL — BIBLIOTECA
====================================================== */

.ob-footer {
  width: 100%;
  background-color: #000000;
  border-top: 1px solid #c5a200;
  color: #ffffff;
}

.ob-footer-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 3rem 1rem;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2.5rem;
  align-items: stretch;
}

/* ------------------------------------------------------
   BLOQUES
------------------------------------------------------ */
.ob-footer-block h3 {
  font-size: 1.05rem;
  margin-bottom: 1rem;
  font-weight: 600;
}

.ob-footer-block ul {
  list-style: none;
}

.ob-footer-block ul li {
  margin-bottom: 0.5rem;
}

.ob-footer-block a {
  color: #ffffff;
  text-decoration: none;
}

.ob-footer-block a:hover,
.ob-footer-block a:focus {
  color: #c5a200;
}

/* ------------------------------------------------------
   LOGO (CENTRADO VERTICAL)
------------------------------------------------------ */
.ob-footer-logo-block {
  display: flex;
  align-items: center;
  justify-content: center;
}

.ob-footer-logo {
  max-width: 140px;
  height: auto;
}

/* ------------------------------------------------------
   CONTACTO
------------------------------------------------------ */
.ob-footer-block p {
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

/* ------------------------------------------------------
   COPYRIGHT
------------------------------------------------------ */
.ob-footer-copy {
  width: 100%;
  text-align: center;
  font-size: 0.85rem;
  color: #ffffff;
  padding: 1.5rem 1rem;
  border-top: 1px solid #c5a200;
  letter-spacing: 0.3px;
}

/* ======================================================
   RESPONSIVE
====================================================== */
@media (max-width: 1024px) {
  .ob-footer-container {
    grid-template-columns: repeat(2, 1fr);
    row-gap: 3rem;
  }

  .ob-footer-logo-block {
    grid-column: span 2;
  }
}

@media (max-width: 480px) {
  .ob-footer-container {
    grid-template-columns: 1fr;
  }

  .ob-footer-logo-block {
    grid-column: span 1;
  }
}

/* ======================================================
   ACCESIBILIDAD
====================================================== */
.ob-footer a:focus {
  outline: 2px solid #c5a200;
  outline-offset: 3px;
}