/* ===========================================
   BIBLIOTECA VIRTUAL AGTECH
   Versión 9B: + sidebar de filtros + alertas + modal
   =========================================== */

:root {
    --azul-oscuro: #1B3A6B;
    --azul-medio: #2A4F8F;
    --celeste: #29ABE2;
    --celeste-claro: #5BC0E8;
    --dorado: #F5A623;
    --dorado-claro: #FFC857;
    --plata: #F4F4F4;
    --gris-claro: #E8ECEF;
    --gris-medio: #9CA3AF;
    --gris-oscuro: #4B5563;
    --texto: #1F2937;
    --blanco: #FFFFFF;
    --error: #DC2626;
    --error-bg: #FEE2E2;
    --exito: #059669;
    --exito-bg: #D1FAE5;
    --warning: #D97706;
    --warning-bg: #FEF3C7;
    --sombra-sm: 0 1px 3px rgba(27, 58, 107, 0.08);
    --sombra-md: 0 4px 12px rgba(27, 58, 107, 0.10);
    --sombra-lg: 0 12px 32px rgba(27, 58, 107, 0.15);
    --sombra-xl: 0 20px 60px rgba(27, 58, 107, 0.20);
    --radio-sm: 6px;
    --radio-md: 10px;
    --radio-lg: 16px;
    --radio-xl: 24px;
    --t-rapida: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --t-media: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --t-lenta: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
    font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
    background: var(--plata);
    color: var(--texto);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Sora', sans-serif;
    font-weight: 700;
    color: var(--azul-oscuro);
    line-height: 1.25;
    letter-spacing: -0.01em;
}

a { color: var(--celeste); text-decoration: none; transition: color var(--t-rapida); }
a:hover { color: var(--azul-oscuro); }
img { max-width: 100%; height: auto; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

/* ===========================================
   HEADER
   =========================================== */

.header {
    background: var(--blanco);
    border-bottom: 1px solid var(--gris-claro);
    padding: 0 2rem;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--sombra-sm);
}

.header__brand { display: flex; align-items: center; gap: 12px; }
.header__logo { height: 44px; width: auto; }

.header__logo-placeholder {
    height: 44px;
    width: 44px;
    background: linear-gradient(135deg, var(--azul-oscuro) 0%, var(--celeste) 100%);
    border-radius: var(--radio-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--blanco);
    font-family: 'Sora', sans-serif;
    font-weight: 700;
    font-size: 18px;
}

.header__titulo {
    font-family: 'Sora', sans-serif;
    font-weight: 700;
    font-size: 20px;
    color: var(--azul-oscuro);
}

.header__titulo-sub {
    font-size: 11px;
    color: var(--celeste);
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-top: 2px;
}

.header__user { display: flex; align-items: center; gap: 16px; }

.user-chip {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 16px 8px 8px;
    background: var(--plata);
    border-radius: 100px;
    transition: background var(--t-rapida);
}

.user-chip:hover { background: var(--gris-claro); }
.user-chip__foto { width: 36px; height: 36px; border-radius: 50%; object-fit: cover; }
.user-chip__nombre { font-size: 14px; font-weight: 500; color: var(--texto); }
.user-chip__email { font-size: 12px; color: var(--gris-medio); }

.badge {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 100px;
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.badge-admin { background: var(--dorado); color: var(--azul-oscuro); }

/* ===========================================
   HERO Y BUSCADOR
   =========================================== */

.hero {
    background: linear-gradient(135deg, var(--azul-oscuro) 0%, var(--azul-medio) 60%, var(--celeste) 130%);
    color: var(--blanco);
    padding: 64px 2rem 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -100px; right: -100px;
    width: 400px; height: 400px;
    background: radial-gradient(circle, rgba(245, 166, 35, 0.15), transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -150px; left: -100px;
    width: 350px; height: 350px;
    background: radial-gradient(circle, rgba(91, 192, 232, 0.20), transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero__contenido { position: relative; z-index: 1; max-width: 800px; margin: 0 auto; }

.hero__titulo {
    font-family: 'Sora', sans-serif;
    font-weight: 700;
    font-size: clamp(2rem, 4.5vw, 3.5rem);
    line-height: 1.1;
    color: var(--blanco);
    margin-bottom: 16px;
}

.hero__titulo .destacado {
    background: linear-gradient(120deg, var(--dorado) 0%, var(--dorado-claro) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero__subtitulo {
    font-size: clamp(1rem, 1.5vw, 1.15rem);
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 40px;
}

.buscador {
    background: var(--blanco);
    border-radius: var(--radio-lg);
    padding: 6px;
    display: flex;
    align-items: center;
    gap: 8px;
    box-shadow: var(--sombra-xl);
    transition: transform var(--t-media), box-shadow var(--t-media);
    max-width: 720px;
    margin: 0 auto;
}

.buscador:focus-within { transform: translateY(-2px); }
.buscador__icono { color: var(--gris-medio); padding-left: 16px; flex-shrink: 0; }

.buscador__input {
    flex: 1;
    border: none;
    outline: none;
    padding: 16px 8px;
    font-size: 16px;
    font-family: inherit;
    color: var(--texto);
    background: transparent;
    min-width: 0;
}

.buscador__input::placeholder { color: var(--gris-medio); font-size: 14px; }

.buscador__boton {
    background: linear-gradient(135deg, var(--azul-oscuro), var(--azul-medio));
    color: var(--blanco);
    padding: 14px 24px;
    border-radius: var(--radio-md);
    font-weight: 600;
    font-size: 15px;
    transition: transform var(--t-rapida);
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.buscador__boton:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 24px rgba(27, 58, 107, 0.30);
}

.sugerencias { margin-top: 32px; display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }

.sugerencia-chip {
    background: rgba(255, 255, 255, 0.10);
    color: var(--blanco);
    padding: 8px 16px;
    border-radius: 100px;
    font-size: 13px;
    font-weight: 500;
    border: 1px solid rgba(255, 255, 255, 0.15);
    cursor: pointer;
    transition: all var(--t-rapida);
}

.sugerencia-chip:hover {
    background: rgba(255, 255, 255, 0.20);
    border-color: var(--dorado);
}

.sugerencia-chip--info {
    background: rgba(245, 166, 35, 0.15);
    border-color: var(--dorado);
}

/* ===========================================
   LAYOUT BUSCADOR (sidebar + contenido)
   =========================================== */

.layout-buscador {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 32px;
    max-width: 1400px;
    margin: 0 auto;
    padding: 32px 2rem;
    align-items: start;
}

.sidebar-filtros {
    position: sticky;
    top: 88px;
    max-height: calc(100vh - 100px);
    overflow-y: auto;
    background: var(--blanco);
    border-radius: var(--radio-md);
    box-shadow: var(--sombra-sm);
    scrollbar-width: thin;
    scrollbar-color: var(--celeste) var(--gris-claro);
}

.sidebar-filtros::-webkit-scrollbar { width: 6px; }
.sidebar-filtros::-webkit-scrollbar-track { background: var(--gris-claro); }
.sidebar-filtros::-webkit-scrollbar-thumb { background: var(--celeste); border-radius: 4px; }

.sidebar-filtros__inner { padding: 20px; }

.sidebar__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--gris-claro);
}

.sidebar__titulo {
    font-family: 'Sora', sans-serif;
    font-size: 16px;
    font-weight: 700;
    color: var(--azul-oscuro);
    margin: 0;
}

.btn-limpiar {
    color: var(--celeste);
    font-size: 12px;
    font-weight: 600;
    padding: 4px 8px;
    border-radius: var(--radio-sm);
    transition: background var(--t-rapida);
}

.btn-limpiar:hover { background: rgba(41, 171, 226, 0.10); }

.filtro-grupo {
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--gris-claro);
}

.filtro-grupo:last-child { border-bottom: none; margin-bottom: 0; }

.filtro-grupo__titulo {
    font-family: 'Sora', sans-serif;
    font-size: 13px;
    font-weight: 600;
    color: var(--azul-oscuro);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.filtro-checkbox {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 0;
    font-size: 13px;
    color: var(--gris-oscuro);
    cursor: pointer;
    transition: color var(--t-rapida);
    user-select: none;
}

.filtro-checkbox:hover { color: var(--azul-oscuro); }

.filtro-checkbox input[type="checkbox"] {
    accent-color: var(--celeste);
    width: 16px;
    height: 16px;
    cursor: pointer;
    margin: 0;
}

.filtro-checkbox span:first-of-type { flex: 1; }

.filtro-contador {
    color: var(--gris-medio);
    font-size: 11px;
}

.filtro-rango {
    display: flex;
    gap: 8px;
    align-items: center;
}

.filtro-rango label {
    flex: 1;
    font-size: 12px;
    color: var(--gris-oscuro);
}

.filtro-rango input {
    width: 100%;
    padding: 6px 8px;
    border: 1px solid var(--gris-claro);
    border-radius: var(--radio-sm);
    font-size: 13px;
    margin-top: 2px;
}

.filtro-rango input:focus {
    outline: none;
    border-color: var(--celeste);
    box-shadow: 0 0 0 2px rgba(41, 171, 226, 0.15);
}

.filtro-hint {
    color: var(--gris-medio);
    font-size: 11px;
    margin-top: 6px;
    display: block;
}

.filtro-lista {
    max-height: 200px;
    overflow-y: auto;
    scrollbar-width: thin;
}

.filtro-vacio {
    color: var(--gris-medio);
    font-size: 12px;
    font-style: italic;
    padding: 4px 0;
}

.filtro-select {
    width: 100%;
    padding: 8px 10px;
    border: 1px solid var(--gris-claro);
    border-radius: var(--radio-sm);
    font-size: 13px;
    background: var(--blanco);
    color: var(--texto);
    cursor: pointer;
}

.filtro-select:focus {
    outline: none;
    border-color: var(--celeste);
}

/* ===========================================
   CONTENIDO BUSCADOR
   =========================================== */

.contenido-buscador { min-width: 0; }

.seccion { margin-bottom: 56px; }

.seccion__header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: 24px;
    gap: 16px;
}

.seccion__titulo {
    font-family: 'Sora', sans-serif;
    font-size: 28px;
    font-weight: 700;
    color: var(--azul-oscuro);
    display: flex;
    align-items: center;
    gap: 12px;
}

.seccion__icono {
    width: 36px; height: 36px;
    background: linear-gradient(135deg, var(--celeste), var(--azul-medio));
    border-radius: var(--radio-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--blanco);
    font-size: 18px;
}

.seccion__icono--dorado { background: linear-gradient(135deg, var(--dorado), var(--dorado-claro)); }
.seccion__subtitulo { color: var(--gris-medio); font-size: 14px; margin-top: 4px; }

/* Carrusel */
.carrusel {
    display: flex;
    gap: 20px;
    overflow-x: auto;
    overflow-y: visible;
    padding: 8px 4px 24px;
    scrollbar-width: thin;
    scrollbar-color: var(--celeste) var(--gris-claro);
}

.carrusel::-webkit-scrollbar { height: 8px; }
.carrusel::-webkit-scrollbar-track { background: var(--gris-claro); border-radius: 4px; }
.carrusel::-webkit-scrollbar-thumb { background: var(--celeste); border-radius: 4px; }

.carrusel__item { flex-shrink: 0; }

/* ===========================================
   TARJETAS DE LIBROS
   =========================================== */

.libro-card {
    width: 220px;
    background: var(--blanco);
    border-radius: var(--radio-md);
    overflow: hidden;
    box-shadow: var(--sombra-sm);
    transition: transform var(--t-media), box-shadow var(--t-media);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    height: 100%;
}

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

.libro-card__portada {
    aspect-ratio: 2 / 3;
    background: linear-gradient(135deg, var(--azul-oscuro) 0%, var(--celeste) 100%);
    position: relative;
    overflow: hidden;
}

.libro-card__portada img { width: 100%; height: 100%; object-fit: cover; }

.libro-card__portada-fallback {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 16px;
    color: var(--blanco);
}

.libro-card__portada-fallback-titulo {
    font-family: 'Sora', sans-serif;
    font-weight: 700;
    font-size: 14px;
    line-height: 1.3;
    margin-bottom: 8px;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 4;
    -webkit-box-orient: vertical;
}

.libro-card__portada-fallback-autor {
    font-size: 11px;
    color: rgba(255, 255, 255, 0.75);
}

.libro-card__badge {
    position: absolute;
    top: 8px; left: 8px;
    background: rgba(27, 58, 107, 0.85);
    color: var(--blanco);
    padding: 4px 10px;
    border-radius: 100px;
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    backdrop-filter: blur(8px);
}

.libro-card__badge--institucional { background: var(--dorado); color: var(--azul-oscuro); }

.libro-card__contenido { padding: 14px; flex: 1; display: flex; flex-direction: column; }

.libro-card__titulo {
    font-family: 'Sora', sans-serif;
    font-size: 14px;
    font-weight: 600;
    color: var(--azul-oscuro);
    line-height: 1.3;
    margin-bottom: 6px;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    min-height: 36px;
}

.libro-card__autor {
    font-size: 12px;
    color: var(--gris-oscuro);
    margin-bottom: 8px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.libro-card__meta {
    margin-top: auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 11px;
    color: var(--gris-medio);
}

/* Tarjeta horizontal de resultado */
.libro-resultado {
    background: var(--blanco);
    border-radius: var(--radio-md);
    padding: 20px;
    display: grid;
    grid-template-columns: 100px 1fr auto;
    gap: 20px;
    box-shadow: var(--sombra-sm);
    transition: box-shadow var(--t-media);
    margin-bottom: 16px;
}

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

.libro-resultado__portada {
    width: 100px;
    aspect-ratio: 2 / 3;
    border-radius: var(--radio-sm);
    overflow: hidden;
    background: linear-gradient(135deg, var(--azul-oscuro), var(--celeste));
    flex-shrink: 0;
    position: relative;
}

.libro-resultado__portada img { width: 100%; height: 100%; object-fit: cover; }

.libro-resultado__info { display: flex; flex-direction: column; min-width: 0; }

.libro-resultado__titulo {
    font-family: 'Sora', sans-serif;
    font-size: 18px;
    font-weight: 700;
    color: var(--azul-oscuro);
    margin-bottom: 6px;
    line-height: 1.3;
}

.libro-resultado__autor { color: var(--gris-oscuro); font-size: 14px; margin-bottom: 4px; }

.libro-resultado__meta {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
    font-size: 12px;
    color: var(--gris-medio);
    margin-bottom: 12px;
}

.libro-resultado__badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 8px;
    border-radius: 100px;
    font-size: 11px;
    font-weight: 600;
}

.badge-acceso-1 { background: rgba(245, 166, 35, 0.15); color: var(--dorado); }
.badge-acceso-2 { background: rgba(5, 150, 105, 0.15); color: var(--exito); }
.badge-acceso-3 { background: rgba(217, 119, 6, 0.15); color: var(--warning); }
.badge-acceso-4 { background: rgba(220, 38, 38, 0.10); color: var(--error); }

.libro-resultado__sinopsis { font-size: 14px; line-height: 1.6; color: var(--texto); margin-bottom: 12px; }

.libro-resultado__sinopsis--cargando {
    color: var(--gris-medio);
    font-style: italic;
}

.libro-resultado__sinopsis--cargando::before { content: '⏳ '; }

.libro-resultado__temas { display: flex; flex-wrap: wrap; gap: 6px; }

.tema-chip {
    background: var(--plata);
    color: var(--gris-oscuro);
    padding: 3px 10px;
    border-radius: 100px;
    font-size: 11px;
    font-weight: 500;
}

.libro-resultado__acciones {
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: stretch;
}

/* ===========================================
   BOTONES
   =========================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: var(--radio-sm);
    font-weight: 600;
    font-size: 14px;
    transition: all var(--t-rapida);
    text-align: center;
    white-space: nowrap;
    border: 1px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, var(--azul-oscuro), var(--azul-medio));
    color: var(--blanco);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(27, 58, 107, 0.30);
    color: var(--blanco);
}

.btn-secondary {
    background: var(--blanco);
    color: var(--azul-oscuro);
    border-color: var(--gris-claro);
}

.btn-secondary:hover { border-color: var(--celeste); color: var(--celeste); }

.btn-dorado {
    background: linear-gradient(135deg, var(--dorado), var(--dorado-claro));
    color: var(--azul-oscuro);
}

.btn-dorado:hover { transform: translateY(-1px); color: var(--azul-oscuro); }

.btn-peligro {
    background: var(--blanco);
    color: var(--error);
    border-color: var(--error);
}

.btn-peligro:hover { background: var(--error); color: var(--blanco); }

.btn-pequeno { padding: 6px 14px; font-size: 13px; }

/* ===========================================
   ALERTAS Y ESTADOS
   =========================================== */

.alerta {
    padding: 14px 18px;
    border-radius: var(--radio-md);
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
}

.alerta-error { background: var(--error-bg); color: var(--error); border-left: 4px solid var(--error); }
.alerta-exito { background: var(--exito-bg); color: var(--exito); border-left: 4px solid var(--exito); }
.alerta-info { background: rgba(41, 171, 226, 0.10); color: var(--azul-oscuro); border-left: 4px solid var(--celeste); }

/* Alerta flotante (esquina) */
.alerta-flotante {
    position: fixed;
    bottom: 24px;
    right: 24px;
    background: var(--blanco);
    padding: 20px;
    border-radius: var(--radio-md);
    box-shadow: var(--sombra-xl);
    max-width: 360px;
    display: flex;
    gap: 12px;
    align-items: flex-start;
    z-index: 1000;
    animation: slideInRight 400ms cubic-bezier(0.4, 0, 0.2, 1);
    border-left: 4px solid var(--dorado);
}

@keyframes slideInRight {
    from { opacity: 0; transform: translateX(20px); }
    to { opacity: 1; transform: translateX(0); }
}

.alerta-flotante__icono { font-size: 24px; flex-shrink: 0; }

.alerta-flotante__contenido { flex: 1; }

.alerta-flotante__contenido strong {
    color: var(--azul-oscuro);
    display: block;
    margin-bottom: 4px;
}

.alerta-flotante__contenido p {
    font-size: 13px;
    color: var(--gris-oscuro);
    margin-bottom: 12px;
}

.alerta-flotante__acciones { display: flex; gap: 8px; }

.estado-vacio { text-align: center; padding: 64px 24px; color: var(--gris-medio); }
.estado-vacio__icono { font-size: 48px; margin-bottom: 16px; opacity: 0.6; }
.estado-vacio__titulo { font-family: 'Sora', sans-serif; font-size: 20px; color: var(--azul-oscuro); margin-bottom: 8px; }
.estado-vacio__texto { font-size: 14px; max-width: 400px; margin: 0 auto; }

.spinner {
    display: inline-block;
    width: 20px; height: 20px;
    border: 3px solid var(--gris-claro);
    border-top-color: var(--celeste);
    border-radius: 50%;
    animation: girar 0.8s linear infinite;
}

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

.cargando-overlay {
    position: fixed;
    inset: 0;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 999;
    flex-direction: column;
    gap: 16px;
}

.cargando-overlay .spinner { width: 48px; height: 48px; border-width: 5px; }
.cargando-overlay__texto { color: var(--azul-oscuro); font-weight: 600; }

/* ===========================================
   MODAL
   =========================================== */

.modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal__backdrop {
    position: absolute;
    inset: 0;
    background: rgba(27, 58, 107, 0.65);
    backdrop-filter: blur(4px);
}

.modal__contenido {
    position: relative;
    background: var(--blanco);
    border-radius: var(--radio-lg);
    padding: 32px;
    max-width: 600px;
    width: 100%;
    box-shadow: var(--sombra-xl);
    animation: subir 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes subir {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.modal__cerrar {
    position: absolute;
    top: 16px; right: 16px;
    width: 32px; height: 32px;
    border-radius: 50%;
    background: var(--plata);
    color: var(--gris-oscuro);
    font-size: 20px;
    font-weight: 600;
    line-height: 1;
}

.modal__cerrar:hover { background: var(--gris-claro); color: var(--azul-oscuro); }

.modal__contenido h3 {
    font-family: 'Sora', sans-serif;
    color: var(--azul-oscuro);
    margin-bottom: 12px;
}

.tabla-ayuda {
    width: 100%;
    border-collapse: collapse;
    margin-top: 16px;
}

.tabla-ayuda td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--gris-claro);
    font-size: 13px;
}

.tabla-ayuda code {
    background: var(--plata);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: var(--azul-oscuro);
    font-size: 12px;
}

/* ===========================================
   FOOTER
   =========================================== */

.footer {
    background: var(--azul-oscuro);
    color: rgba(255, 255, 255, 0.7);
    padding: 32px 2rem;
    text-align: center;
    margin-top: 64px;
    font-size: 13px;
}

.footer__links { display: flex; gap: 24px; justify-content: center; margin-bottom: 12px; }
.footer__links a { color: rgba(255, 255, 255, 0.85); }
.footer__links a:hover { color: var(--dorado); }

/* ===========================================
   ADMIN (heredado)
   =========================================== */

.admin-tabla {
    width: 100%;
    background: var(--blanco);
    border-radius: var(--radio-md);
    overflow: hidden;
    box-shadow: var(--sombra-sm);
    border-collapse: collapse;
}

.admin-tabla th, .admin-tabla td {
    padding: 14px 16px;
    text-align: left;
    border-bottom: 1px solid var(--gris-claro);
    vertical-align: middle;
}

.admin-tabla th {
    background: var(--plata);
    font-family: 'Sora', sans-serif;
    font-size: 12px;
    font-weight: 700;
    color: var(--azul-oscuro);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.admin-tabla tbody tr:hover { background: rgba(41, 171, 226, 0.04); }

.admin-tabla__portada-mini {
    width: 50px; height: 70px;
    object-fit: cover;
    border-radius: 4px;
    background: var(--gris-claro);
}

.formulario {
    background: var(--blanco);
    padding: 32px;
    border-radius: var(--radio-md);
    box-shadow: var(--sombra-sm);
    max-width: 700px;
}

.campo { margin-bottom: 20px; }

.campo label {
    display: block;
    font-weight: 600;
    color: var(--azul-oscuro);
    margin-bottom: 6px;
    font-size: 14px;
}

.campo input[type="text"], .campo input[type="number"], .campo textarea, .campo select {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--gris-claro);
    border-radius: var(--radio-sm);
    font-family: inherit;
    font-size: 14px;
    color: var(--texto);
    background: var(--blanco);
    transition: border-color var(--t-rapida);
}

.campo input:focus, .campo textarea:focus, .campo select:focus {
    outline: none;
    border-color: var(--celeste);
    box-shadow: 0 0 0 3px rgba(41, 171, 226, 0.15);
}

.campo textarea { min-height: 120px; resize: vertical; }
.campo small { display: block; color: var(--gris-medio); font-size: 12px; margin-top: 4px; }

.campo-archivo {
    border: 2px dashed var(--gris-claro);
    border-radius: var(--radio-md);
    padding: 32px;
    text-align: center;
    cursor: pointer;
    transition: border-color var(--t-rapida), background var(--t-rapida);
}

.campo-archivo:hover { border-color: var(--celeste); background: rgba(41, 171, 226, 0.04); }
.campo-archivo input[type="file"] { display: none; }
.campo-archivo__icono { font-size: 32px; margin-bottom: 8px; }
.campo-archivo__texto { color: var(--gris-oscuro); font-size: 14px; }
.campo-archivo__sub { color: var(--gris-medio); font-size: 12px; margin-top: 4px; }

.campo-archivo--seleccionado {
    border-color: var(--exito);
    background: var(--exito-bg);
    color: var(--exito);
}

.acciones-formulario {
    display: flex;
    gap: 12px;
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid var(--gris-claro);
}

/* ===========================================
   RESPONSIVE
   =========================================== */

@media (max-width: 1024px) {
    .layout-buscador {
        grid-template-columns: 240px 1fr;
        gap: 24px;
    }
}

@media (max-width: 768px) {
    .layout-buscador { grid-template-columns: 1fr; gap: 16px; padding: 24px 1rem; }
    
    .sidebar-filtros {
        position: relative;
        top: 0;
        max-height: none;
        order: 2;
    }
    
    .header { padding: 0 1rem; }
    .header__titulo { font-size: 16px; }
    .header__titulo-sub { display: none; }
    .user-chip__nombre, .user-chip__email { display: none; }
    
    .hero { padding: 48px 1rem 64px; }
    
    .buscador { flex-direction: column; padding: 16px; gap: 12px; }
    .buscador__input { width: 100%; }
    .buscador__boton { width: 100%; }
    
    .libro-resultado { grid-template-columns: 80px 1fr; gap: 14px; }
    .libro-resultado__acciones { grid-column: 1 / -1; flex-direction: row; }
    
    .libro-card { width: 160px; }
    .seccion__titulo { font-size: 22px; }
    
    .alerta-flotante {
        bottom: 12px;
        right: 12px;
        left: 12px;
        max-width: none;
    }
}