html {
    scroll-behavior: smooth;
}

header.sticky {
    position: sticky;
    top: 0;
    z-index: 100;
}

/* Fondo estilo biblioteca/madera */
body {
    background: 
        repeating-linear-gradient(
            90deg,
            rgba(139, 90, 43, 0.04) 0px,
            rgba(139, 90, 43, 0.04) 2px,
            transparent 2px,
            transparent 80px
        ),
        linear-gradient(135deg, #f5e3c4 0%, #ecdcb8 50%, #e2cfa6 100%);
    min-height: 100vh;
}

header {
    background: linear-gradient(90deg, #6d4427 0%, #8a5b35 50%, #6d4427 100%);
    border-bottom: 3px solid #4a2f1c;
    box-shadow: 0 4px 12px rgba(74, 47, 28, 0.35);
}

header h1 {
    color: #faf3e6;
}

header h1 span {
    color: #e2b877;
}

header #searchInput {
    background: rgba(255, 255, 255, 0.22);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: #faf3e6;
}

header #searchInput::placeholder {
    color: rgba(245, 230, 211, 0.7);
}

header #searchInput:focus {
    background: rgba(255, 255, 255, 0.3);
    border-color: #e2b877;
}

header #openModalBtn {
    background: linear-gradient(135deg, #e2b877 0%, #cd9a55 100%);
    color: #3d2518;
    font-weight: 600;
}

header #openModalBtn:hover {
    background: linear-gradient(135deg, #d5a765 0%, #b9843f 100%);
}

/* Modal styles */
#modalOverlay,
#editModalOverlay,
#downloadModalOverlay {
    backdrop-filter: blur(4px);
    background: rgba(0, 0, 0, 0.6);
}

#modalOverlay .rounded-xl,
#editModalOverlay .rounded-xl,
#downloadModalOverlay .rounded-xl {
    margin: auto;
}

/* Book cards */
.book-card {
    transition: all 0.2s ease;
    border: none !important;
    background: linear-gradient(145deg, #5e4030 0%, #4a3325 100%);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.book-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.4);
    border-color: #e2b877;
}

.book-card img {
    transition: transform 0.3s ease;
    object-fit: cover;
}

.book-card:hover img {
    transform: scale(1.05);
}

.book-card h3 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.3;
    color: #faf3e6;
}

.book-card .category-badge {
    background: rgba(232, 192, 125, 0.9);
    color: #3d2518;
}

.book-card .author {
    color: #d8b076;
}

/* Placeholder para imágenes */
.book-cover-wrapper {
    background: linear-gradient(145deg, #4a3325 0%, #3a281b 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.book-cover-placeholder {
    color: #a8875f;
    text-align: center;
    padding: 16px;
}

.book-cover-placeholder svg {
    width: 40px;
    height: 40px;
    margin-bottom: 6px;
    opacity: 0.5;
}

/* Botones LEER y DESCARGAR en tarjetas */
.book-card .flex a:first-child {
    background: linear-gradient(135deg, #e2b877 0%, #cd9a55 100%);
    color: #3d2518;
}

.book-card .flex a:first-child:hover {
    background: linear-gradient(135deg, #d5a765 0%, #b9843f 100%);
}

.book-card .flex .download-btn {
    background: rgba(255, 255, 255, 0.14);
    color: #faf3e6;
    border: none;
    cursor: pointer;
}

.book-card .flex .download-btn:hover {
    background: rgba(255, 255, 255, 0.24);
}

.book-card .read-btn {
    background: linear-gradient(135deg, #e2b877 0%, #cd9a55 100%);
    color: #3d2518;
}

.book-card .read-btn:hover {
    background: linear-gradient(135deg, #d5a765 0%, #b9843f 100%);
}

/* Botones de editar y eliminar */
.book-card .action-buttons {
    opacity: 0;
    transition: opacity 0.2s ease;
}

.book-card:hover .action-buttons {
    opacity: 1;
}

.action-btn {
    width: 24px;
    height: 24px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.action-btn svg {
    width: 12px;
    height: 12px;
}

.edit-btn {
    background-color: rgba(232, 192, 125, 0.9);
    color: #3d2518;
}

.edit-btn:hover {
    background-color: #e2b877;
}

.delete-btn {
    background-color: rgba(220, 38, 38, 0.8);
    color: white;
}

.delete-btn:hover {
    background-color: #dc2626;
}

/* Category buttons — separadores de hojas (índice de libro) */
.cat-btn {
    position: relative;
    padding: 5px 14px;
    transition: all 0.2s ease;
    clip-path: polygon(0% 0%, 100% 0%, 100% 100%, 14% 100%, 0% 78%);
    border: none;
    font-weight: 700;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.25);
    filter: saturate(0.9) brightness(1);
}

#categoryNav .cat-btn {
    color: #ffffff;
}

.cat-btn:hover {
    transform: translateY(-1px);
    filter: saturate(1.05) brightness(1.08);
}

.cat-btn[data-cat="Todos"] {
    background: linear-gradient(135deg, #e2b877 0%, #cd9a55 100%);
}

#categoryNav .cat-btn[data-cat="Todos"] {
    color: #3d2518;
    text-shadow: none;
}

.cat-btn[data-cat="Favoritos"] {
    background: linear-gradient(135deg, #e0607a 0%, #bd3a55 100%);
}

.cat-btn[data-cat="Ciberseguridad"] {
    background: linear-gradient(135deg, #d05555 0%, #a83c3c 100%);
}

.cat-btn[data-cat="Programación"] {
    background: linear-gradient(135deg, #5f92cf 0%, #3f6ea8 100%);
}

.cat-btn[data-cat="Tecnología"] {
    background: linear-gradient(135deg, #4db3a4 0%, #338f84 100%);
}

.cat-btn[data-cat="Ficción"] {
    background: linear-gradient(135deg, #9e81c9 0%, #7d5fa8 100%);
}

.cat-btn[data-cat="Otros"] {
    background: linear-gradient(135deg, #e8a04f 0%, #c97f2f 100%);
}

/* Pestaña seleccionada: se eleva y se ilumina */
.cat-btn.bg-gray-800 {
    transform: translateY(-2px);
    filter: saturate(1.15) brightness(1.12);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.35);
}

/* Botón scroll to top */
#scrollToTopBtn {
    background: linear-gradient(135deg, #e2b877 0%, #cd9a55 100%);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    cursor: pointer;
}

#scrollToTopBtn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
}

#scrollToTopBtn.visible {
    opacity: 1;
    pointer-events: auto;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 6px;
    margin-top: 24px;
    padding: 12px;
}

.pagination button {
    padding: 6px 12px;
    border-radius: 6px;
    background: rgba(94, 64, 48, 0.8);
    color: #faf3e6;
    border: 1px solid rgba(232, 192, 125, 0.3);
    cursor: pointer;
    transition: all 0.2s ease;
}

.pagination button:hover:not(:disabled) {
    background: rgba(94, 64, 48, 1);
    border-color: #e2b877;
}

.pagination button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.pagination button.active {
    background: linear-gradient(135deg, #e2b877 0%, #cd9a55 100%);
    color: #3d2518;
    border-color: transparent;
}

.pagination span {
    color: #d8b076;
    padding: 0 12px;
}

/* Toast notifications */
.toast {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 20px;
    border-radius: 8px;
    color: #faf3e6;
    font-size: 13px;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    animation: toastIn 0.3s ease, toastOut 0.3s ease 2.7s forwards;
    min-width: 180px;
    text-align: center;
}

.toast-icon {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.toast-success {
    background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
}

.toast-error {
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
}

.toast-info {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
}

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

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

/* Mensajes de estado */
#loadingMsg,
.empty-state p {
    color: #d8b076;
}

/* =========================================
   ANIMACIÓN DEL LIBRO DE CARGA (LOADING)
   ========================================= */
.book-loader {
    position: relative;
    width: 60px;
    height: 40px;
    perspective: 150px;
    transform-style: preserve-3d;
}

.book-page {
    position: absolute;
    width: 30px;
    height: 40px;
    /* Color hoja de libro antiguo */
    background: linear-gradient(135deg, #faf3e6 0%, #e6d0b3 100%); 
    border: 1px solid #d8b076;
    border-radius: 2px 6px 6px 2px;
    transform-origin: left center;
    animation: flipPage 1.2s infinite linear;
    box-shadow: 2px 2px 4px rgba(0,0,0,0.3);
    left: 30px; /* Posicionado en la mitad derecha */
}

/* Retrasamos la animación de cada página para que vayan una detrás de otra */
.book-page:nth-child(1) { animation-delay: 0s; }
.book-page:nth-child(2) { animation-delay: 0.4s; }
.book-page:nth-child(3) { animation-delay: 0.8s; }

/* La magia 3D de pasar la hoja */
@keyframes flipPage {
    0% {
        transform: rotateY(0deg);
        z-index: 1;
    }
    50% {
        transform: rotateY(-90deg);
        z-index: 2;
        background: #faf3e6;
    }
    100% {
        transform: rotateY(-180deg);
        z-index: 3;
        /* Oscurecemos un poco la hoja cuando termina de pasar por la sombra */
        background: #e2b877; 
    }
}

/* =========================================
   ANIMACIÓN DEL LIBRO DE CARGA (LOADING)
   ========================================= */
@media (max-width: 768px) {
    /* 1. HEADER: Apilamos todo para que respire */
    header {
        flex-direction: column !important;
        padding: 15px !important;
        gap: 15px !important;
        height: auto !important;
        position: relative !important; /* Evita que flote sobre otras cosas */
    }
    
    header > div { 
        /* Contenedor de botones y buscador */
        flex-direction: column !important;
        width: 100% !important;
        gap: 10px !important;
    }

    header input, 
    header button,
    header .action-btn {
        width: 100% !important; /* Todo a lo ancho de la pantalla */
        margin: 0 !important;
    }

    /* 2. MODALES: Cubrir todo y no cortar la parte de arriba */
    .fixed.inset-0 {
        z-index: 9999 !important; /* ¡Obligamos a que tape el Header! */
        padding: 15px !important;
        align-items: flex-start !important; /* Empezar desde arriba, no del centro */
        overflow-y: auto !important; /* Permitir scroll con el dedo */
    }
    
    .fixed.inset-0 > div {
        width: 100% !important;
        max-width: 100% !important;
        margin: 10px auto 40px auto !important; /* Espacio para respirar */
        max-height: none !important; /* Dejar que el formulario mida lo que tenga que medir */
    }

    /* 3. BOTONES DE LAS TARJETAS: Apilarlos en celulares para que no se aplasten */
    .book-card .mt-auto.flex {
        flex-direction: column !important; /* Pone uno arriba del otro */
        gap: 8px !important; /* Separación entre los botones */
    }
    
    .book-card .mt-auto.flex > a,
    .book-card .mt-auto.flex > button {
        width: 100% !important; /* Ocupan todo el ancho de la tarjeta */
        padding: 8px 0 !important; /* Los hace un poco más altos para el dedo */
        border-radius: 6px !important;
        letter-spacing: 1px !important; /* Separa un poquito las letras */
    }
}

/* =========================================
   DISEÑO UNIVERSAL: MODAL DE LOGIN (Igual en PC y Celular)
   ========================================= */
#loginModalOverlay {
    /* 1. Evita recortes en Opera/Chrome forzando el inicio desde arriba */
    align-items: flex-start !important; 
    padding-top: 5vh !important;
    padding-bottom: 5vh !important;
    overflow-y: auto !important; /* Permite scroll si la pantalla es enana */
}

#loginModalOverlay > div {
    /* 2. La caja se comportará como un celular incluso en la PC */
    width: 95% !important; /* En celular ocupa casi todo el ancho */
    max-width: 400px !important; /* En PC no se estira feo, queda del tamaño de un celular centrado */
    
    /* 3. Centrado perfecto a prueba de fallos */
    margin: auto !important; 
    
    /* 4. Altura libre para que respire */
    height: auto !important;
    max-height: none !important;
}

/* =========================================
   VISOR DE LECTURA: REDIMENSIONABLE
   ========================================= */
#readModalOverlay > div {
    resize: both;
    overflow: hidden;
    min-width: min(80vw, 360px);
    min-height: 300px;
    max-width: 96vw;
    max-height: 94vh;
}

#readModalOverlay > div::-webkit-resizer {
    background: rgba(226, 184, 119, 0.55);
    border-radius: 4px 0 0 0;
    background-image: linear-gradient(
        135deg, transparent 50%, rgba(61, 37, 24, 0.5) 50%, rgba(61, 37, 24, 0.5) 55%, transparent 55%),
        linear-gradient(
        135deg, transparent 62%, rgba(61, 37, 24, 0.35) 62%, rgba(61, 37, 24, 0.35) 67%, transparent 67%);
}

/* Handle visible en la esquina para Firefox */
#readModalOverlay > div::-moz-resizer {
    background: rgba(226, 184, 119, 0.55);
}