/* ============================================================
   Tokens — "sala de lectura": tinta profunda, papel cálido, ámbar
   ============================================================ */
:root {
    --tinta:        #101318;  /* fondo general */
    --tinta-suave:  #191d25;  /* superficies */
    --linea:        #2a2f3a;
    --texto:        #e9e6df;
    --texto-tenue:  #9aa0ac;
    --ambar:        #e6a457;  /* acento */
    --papel:        #f5f2ea;  /* reverso de hoja */
    --papel-sombra: #d8d2c4;
    --fuente-ui:      'Inter', system-ui, sans-serif;
    --fuente-display: 'Bricolage Grotesque', 'Inter', sans-serif;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    background: var(--tinta);
    color: var(--texto);
    font-family: var(--fuente-ui);
    -webkit-tap-highlight-color: transparent;
}

/* ============================================================
   Biblioteca (index.php)
   ============================================================ */
.biblioteca { padding: max(20px, env(safe-area-inset-top)) 20px 48px; }

.cabecera { max-width: 960px; margin: 0 auto 28px; }

.cejilla {
    margin: 0 0 6px;
    font-size: 12px;
    letter-spacing: .14em;
    text-transform: uppercase;
    color: var(--ambar);
}

.cabecera h1 {
    margin: 0;
    font-family: var(--fuente-display);
    font-weight: 800;
    font-size: clamp(34px, 7vw, 56px);
    line-height: 1.05;
}

.subtitulo { margin: 10px 0 0; color: var(--texto-tenue); }

.rejilla {
    max-width: 960px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 18px;
}

/* Tarjeta con forma de libro: lomo + portada + ficha */
.tarjeta {
    position: relative;
    display: flex;
    flex-direction: column;
    text-decoration: none;
    color: inherit;
    outline-offset: 4px;
}
.tarjeta:focus-visible { outline: 2px solid var(--ambar); border-radius: 8px; }

.lomo {
    position: absolute;
    inset: 0 auto 58px 0;
    width: 8px;
    border-radius: 6px 0 0 6px;
    background: linear-gradient(180deg, var(--ambar), #b57433);
    transform: translateX(-2px);
}

.portada {
    display: flex;
    align-items: flex-end;
    aspect-ratio: 3 / 4;
    padding: 14px;
    border: 1px solid var(--linea);
    border-left: none;
    border-radius: 0 8px 8px 0;
    background:
        linear-gradient(160deg, rgba(230,164,87,.12), rgba(230,164,87,0) 45%),
        var(--tinta-suave);
    box-shadow: 0 12px 24px -14px rgba(0,0,0,.8);
    transition: transform .25s ease, box-shadow .25s ease;
}
.tarjeta:hover .portada,
.tarjeta:active .portada {
    transform: translateY(-4px) rotate(-1deg);
    box-shadow: 0 20px 32px -16px rgba(0,0,0,.9);
}

.portada-titulo {
    font-family: var(--fuente-display);
    font-weight: 600;
    font-size: 17px;
    line-height: 1.25;
    text-transform: capitalize;
    overflow-wrap: anywhere;
    display: -webkit-box;
    -webkit-line-clamp: 4;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.ficha { padding: 10px 2px 0; display: grid; gap: 2px; }
.ficha-nombre {
    font-size: 13px;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.ficha-datos { font-size: 12px; color: var(--texto-tenue); }

.vacio {
    grid-column: 1 / -1;
    padding: 48px 24px;
    border: 1px dashed var(--linea);
    border-radius: 12px;
    text-align: center;
    color: var(--texto-tenue);
}
.vacio h2 { color: var(--texto); font-family: var(--fuente-display); margin: 0 0 8px; }
.vacio code {
    background: var(--tinta-suave);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--ambar);
    overflow-wrap: anywhere;
}
.pantalla-completa { min-height: 100dvh; display: grid; place-content: center; }
.enlace { color: var(--ambar); }

/* ============================================================
   Visor (visor.php)
   ============================================================ */
.lector {
    height: 100dvh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    overscroll-behavior: none;
}

.barra {
    position: fixed;
    left: 0; right: 0;
    z-index: 20;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    background: linear-gradient(180deg, rgba(16,19,24,.92), rgba(16,19,24,.72));
    backdrop-filter: blur(8px);
    transition: transform .3s ease, opacity .3s ease;
}
.barra-superior { top: 0; padding-top: max(10px, env(safe-area-inset-top)); }
.barra-inferior {
    bottom: 0;
    padding-bottom: max(10px, env(safe-area-inset-bottom));
    background: linear-gradient(0deg, rgba(16,19,24,.92), rgba(16,19,24,.72));
}
.barras-ocultas .barra-superior { transform: translateY(-100%); opacity: 0; }
.barras-ocultas .barra-inferior { transform: translateY(100%);  opacity: 0; }

.boton-volver {
    display: grid;
    place-content: center;
    width: 38px; height: 38px;
    border: 1px solid var(--linea);
    border-radius: 10px;
    color: var(--texto);
    text-decoration: none;
    font-size: 18px;
    background: var(--tinta-suave);
}
.barra-titulo {
    font-family: var(--fuente-display);
    font-weight: 600;
    font-size: 15px;
    text-transform: capitalize;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.progreso {
    flex: 1;
    height: 4px;
    border-radius: 99px;
    background: var(--linea);
    overflow: hidden;
}
.progreso-relleno {
    height: 100%;
    width: 0%;
    border-radius: inherit;
    background: var(--ambar);
    transition: width .25s ease;
}
.indicador {
    font-size: 13px;
    font-variant-numeric: tabular-nums;
    color: var(--texto-tenue);
    min-width: 64px;
    text-align: right;
}

/* --- Escenario 3D ------------------------------------------ */
.escenario {
    flex: 1;
    display: grid;
    place-items: center;
    perspective: 2200px;         /* profundidad del volteo */
    touch-action: none;          /* el swipe lo gestionamos nosotros */
    user-select: none;
}

.libro {
    position: relative;
    transform-style: preserve-3d;
    /* El tamaño lo fija JS según la proporción de la página */
    width: 80vw;
    height: 60vh;
    filter: drop-shadow(0 24px 48px rgba(0,0,0,.65));
}

.capa, .hoja {
    position: absolute;
    inset: 0;
    border-radius: 4px;
    overflow: hidden;
}
.capa canvas, .cara canvas {
    display: block;
    width: 100%;
    height: 100%;
}

.capa-actual { z-index: 3; background: var(--papel); }
.capa-debajo { z-index: 1; background: var(--papel); }

/* Hoja que gira sobre su borde izquierdo */
.hoja {
    z-index: 5;
    transform-origin: left center;
    transform-style: preserve-3d;
    pointer-events: none;
    visibility: hidden;
    will-change: transform;
}
.hoja.activa { visibility: visible; }
.hoja.animando { transition: transform .5s cubic-bezier(.16, .84, .32, 1); }

/* Ligera curvatura de la hoja: se "abomba" hacia el lector a medio giro,
   como una página real en vez de una tabla rígida */
.hoja .cara {
    transform: perspective(1600px) rotateX(0deg);
    transition: transform .1s linear;
}

.cara {
    position: absolute;
    inset: 0;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    overflow: hidden;
    border-radius: 4px;
    background: var(--papel);
}
/* Reverso: el "dorso de papel" de la hoja */
.cara-reverso {
    transform: rotateY(180deg);
    background:
        linear-gradient(105deg, var(--papel) 60%, var(--papel-sombra) 100%);
}

/* Curvatura de la hoja mientras gira: luz/sombra que se mueve con el ángulo.
   --curl va de 0 (plana, en reposo) a 1 (a 90°, máxima curvatura) y vuelve a 0. */
.cara::before {
    content: '';
    position: absolute;
    inset: 0;
    pointer-events: none;
    opacity: var(--curl, 0);
    transition: opacity .1s linear;
}
.cara-frontal::before {
    background: linear-gradient(90deg,
        rgba(0,0,0,.28) 0%,
        rgba(0,0,0,.05) 18%,
        rgba(255,255,255,0) 45%);
}
.cara-reverso::before {
    background: linear-gradient(270deg,
        rgba(0,0,0,.32) 0%,
        rgba(0,0,0,.08) 18%,
        rgba(255,255,255,0) 45%);
}

/* Sombra proyectada por la hoja sobre el libro mientras gira */
.libro::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    pointer-events: none;
    box-shadow: inset 0 0 min(60px, 12vw) rgba(0,0,0, var(--sombra-libro, 0));
    transition: box-shadow .1s linear;
    z-index: 4;
}
/* Sombra que cae sobre la página inferior mientras la hoja gira */
.capa-debajo::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, rgba(0,0,0,.35), rgba(0,0,0,0) 55%);
    opacity: var(--sombra-debajo, 0);
    transition: opacity .1s linear;
    pointer-events: none;
}

.cargando {
    position: absolute;
    inset: 0;
    z-index: 10;
    display: flex;
    gap: 10px;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    color: var(--texto-tenue);
    background: var(--tinta);
}
.cargando.oculto { display: none; }
.anillo {
    width: 18px; height: 18px;
    border: 2px solid var(--linea);
    border-top-color: var(--ambar);
    border-radius: 50%;
    animation: girar 1s linear infinite;
}
@keyframes girar { to { transform: rotate(360deg); } }

@media (prefers-reduced-motion: reduce) {
    .hoja.animando { transition-duration: .01s; }
    .tarjeta:hover .portada { transform: none; }
}