/* ==========================================================================
   CSS PRINCIPAL: EL CULTIVO DE LO ÉTICO
   Diseño UX/UI Premium, Oscuro, Con Acentos Dorados y Verdes Orgánicos
   ========================================================================== */

/* Variables de Diseño (Tokens) */
:root {
    --bg-dark: #070B09;
    --bg-card: rgba(14, 25, 20, 0.65);
    --bg-glass: rgba(7, 11, 9, 0.75);
    --color-primary: #C5A880; /* Dorado Mate / Bronce */
    --color-primary-hover: #D4AF37; /* Dorado Brillante */
    --color-primary-glow: rgba(197, 168, 128, 0.35);
    --color-secondary: #4A6B5D; /* Verde Salvia */
    --color-secondary-light: #6C8E80;
    --text-main: #E6EAE8; /* Blanco Hueso */
    --text-muted: #9AA5A1; /* Gris Verdoso */
    --font-serif: 'Playfair Display', Georgia, serif;
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --transition-smooth: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
    --transition-quick: all 0.2s ease;
    --border-glass: 1px solid rgba(255, 255, 255, 0.08);
}

/* Reset & Estilos Generales */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-family: var(--font-sans);
    background-color: var(--bg-dark);
    color: var(--text-main);
}

body {
    overflow-x: hidden;
    line-height: 1.6;
}

/* Scrollbar Personalizado */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-dark);
}
::-webkit-scrollbar-thumb {
    background: var(--color-secondary);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--color-primary);
}

/* Componentes Comunes */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 2.8rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--color-primary);
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}

/* Botones */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.8rem;
    padding: 0.8rem 2rem;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 50px;
    transition: var(--transition-smooth);
    cursor: pointer;
}

.btn-primary {
    background-color: var(--color-primary);
    color: var(--bg-dark);
    box-shadow: 0 4px 15px var(--color-primary-glow);
    border: 1px solid var(--color-primary);
}

.btn-primary:hover {
    background-color: var(--color-primary-hover);
    border-color: var(--color-primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(212, 175, 55, 0.45);
}

.btn-outline {
    background-color: transparent;
    color: var(--text-main);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-outline:hover {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-2px);
}

.btn-block {
    display: flex;
    width: 100%;
}

/* Header / Navegación */
.main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: var(--bg-glass);
    backdrop-filter: blur(12px);
    border-bottom: var(--border-glass);
    transition: var(--transition-smooth);
}

.main-header.scrolled {
    padding: 0.5rem 0;
    background-color: rgba(6, 11, 9, 0.9);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
    padding: 0 2rem;
    max-width: 1400px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    text-decoration: none;
    color: var(--text-main);
    font-family: var(--font-serif);
    font-weight: 700;
    font-size: 1.4rem;
    transition: var(--transition-quick);
}

.logo:hover {
    color: var(--color-primary);
}

.logo-icon {
    color: var(--color-primary);
    font-size: 1.5rem;
}

.nav-menu ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition-quick);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link:hover, .nav-link.active {
    color: var(--color-primary);
    background-color: rgba(197, 168, 128, 0.08);
}

.menu-toggle {
    display: none;
    font-size: 1.5rem;
    color: var(--text-main);
    cursor: pointer;
}

/* Hero Section */
.hero-section {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    overflow: hidden;
}

.hero-bg-glow {
    position: absolute;
    top: -10%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(74, 107, 93, 0.25) 0%, rgba(7, 11, 9, 0) 70%);
    z-index: 1;
    pointer-events: none;
}

.hero-container {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(197, 168, 128, 0.12);
    border: 1px solid rgba(197, 168, 128, 0.3);
    color: var(--color-primary);
    padding: 0.4rem 1rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 1.5rem;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: 4.5rem;
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: 1.5rem;
}

.hero-title span {
    color: var(--color-primary);
    position: relative;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    max-width: 580px;
}

.hero-actions {
    display: flex;
    gap: 1.5rem;
}

/* 3D Book Mockup in Hero */
.hero-cover-container {
    display: flex;
    justify-content: center;
    perspective: 1200px;
}

.book-3d-wrapper {
    position: relative;
    width: 320px;
    height: 480px;
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.book-3d-wrapper:hover {
    transform: rotateY(-20deg) rotateX(10deg);
}

.book-3d {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.8);
}

.book-front-cover {
    position: absolute;
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 0 4px 4px 0;
    backface-visibility: hidden;
    z-index: 2;
    transform: translateZ(12px);
}

.book-spine {
    position: absolute;
    left: -12px;
    top: 0;
    width: 24px;
    height: 100%;
    background: linear-gradient(90deg, #0e1b15 0%, #1c3227 40%, #0e1b15 100%);
    transform: rotateY(-90deg);
    transform-origin: right center;
    border-radius: 4px 0 0 4px;
}

.book-back {
    position: absolute;
    width: 100%;
    height: 100%;
    background: #090e0c;
    border-radius: 4px 0 0 4px;
    transform: rotateY(180deg) translateZ(12px);
}

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
    font-size: 0.85rem;
    z-index: 2;
}

.scroll-arrow {
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-8px); }
    60% { transform: translateY(-4px); }
}

/* Reading (Flipbook) Section */
.reading-section {
    padding: 6rem 0;
    background: linear-gradient(180deg, var(--bg-dark) 0%, #0d1612 100%);
}

.flipbook-workdesk-wrap {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.flipbook-workdesk {
    width: 100%;
    background: radial-gradient(circle, #1a2c24 0%, #0b110e 100%);
    border: var(--border-glass);
    border-radius: 24px;
    padding: 3rem;
    box-shadow: inset 0 0 80px rgba(0,0,0,0.8), 0 30px 60px rgba(0,0,0,0.6);
    display: flex;
    flex-direction: column;
    align-items: center;
    overflow: hidden;
    touch-action: pan-y pinch-zoom;
}

.flipbook-viewport {
    width: 100%;
    max-width: 1200px;
    height: 700px;
    display: flex;
    justify-content: center;
    align-items: center;
    perspective: 2500px;
    position: relative;
    margin-bottom: 2rem;
    overflow: hidden !important; /* Prevent native scroll clipping */
    touch-action: pan-y pinch-zoom;
}

/* Navigation Overlays (Pestañas laterales) */
.fb-nav-overlay {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    height: 90%;
    width: 65px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    z-index: 15; /* Sits above the pages */
    color: rgba(255, 255, 255, 0.35);
    font-size: 2.2rem;
    transition: var(--transition-quick);
    background: transparent;
    user-select: none;
    border-radius: 12px;
}

.fb-nav-overlay.left {
    left: 10px;
}

.fb-nav-overlay.right {
    right: 10px;
}

.fb-nav-overlay:hover {
    color: var(--color-primary-hover);
}

.fb-nav-overlay.left:hover {
    background: linear-gradient(90deg, rgba(0, 0, 0, 0.4) 0%, rgba(0, 0, 0, 0) 100%);
}

.fb-nav-overlay.right:hover {
    background: linear-gradient(-90deg, rgba(0, 0, 0, 0.4) 0%, rgba(0, 0, 0, 0) 100%);
}

.flipbook-container {
    position: relative;
    width: 960px;
    height: 648px;
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.25, 0.8, 0.25, 1);
    transform-origin: center center;
}

/* Center spine slide styling */
.flipbook-container.closed-left {
    transform: translateX(25%);
}

.flipbook-container.closed-right {
    transform: translateX(-25%);
}

/* Sheets Structure */
.sheet {
    position: absolute;
    top: 0;
    left: 50%;
    width: 50%;
    height: 100%;
    transform-style: preserve-3d;
    transform-origin: left center;
    transition: transform 0.8s cubic-bezier(0.23, 1, 0.32, 1);
    z-index: 1;
}

.page-face {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    background-color: #faf7f2; /* Color Papel */
    box-shadow: inset 0 0 20px rgba(0,0,0,0.1), 0 0 10px rgba(0,0,0,0.15);
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
}

.page-face.front {
    z-index: 2;
    border-radius: 0 8px 8px 0;
}

.page-face.back {
    transform: rotateY(180deg);
    z-index: 1;
    border-radius: 8px 0 0 8px;
}

/* Paper bindings shadow inside */
.page-face.front::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 25px;
    height: 100%;
    background: linear-gradient(90deg, rgba(0,0,0,0.18) 0%, rgba(0,0,0,0) 100%);
    pointer-events: none;
}

.page-face.back::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 25px;
    height: 100%;
    background: linear-gradient(-90deg, rgba(0,0,0,0.18) 0%, rgba(0,0,0,0) 100%);
    pointer-events: none;
}

/* Cover specific styling */
.sheet.cover-sheet .page-face {
    background-color: #0e1b15;
}
.sheet.cover-sheet .page-face.front::after {
    display: none;
}

.page-face canvas {
    width: 100% !important;
    height: 100% !important;
    object-fit: contain;
}

/* Page flipped status class */
.sheet.flipped {
    transform: rotateY(-180deg);
}

/* Flipbook Loading Overlay */
.flipbook-loading {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(7, 11, 9, 0.9);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    z-index: 100;
    border-radius: 12px;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(197, 168, 128, 0.1);
    border-top: 4px solid var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-progress {
    color: var(--color-primary);
    font-weight: 600;
    font-size: 1.2rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Flipbook Toolbar Controls */
.flipbook-toolbar {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    padding: 1rem 2rem;
    background-color: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: var(--border-glass);
    border-radius: 50px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    z-index: 10;
}

.toolbar-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.flipbook-toolbar button {
    background: transparent;
    border: none;
    color: var(--text-main);
    padding: 0.6rem 1rem;
    font-size: 0.9rem;
    border-radius: 30px;
    cursor: pointer;
    transition: var(--transition-quick);
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.flipbook-toolbar button:hover {
    color: var(--color-primary);
    background-color: rgba(255, 255, 255, 0.05);
}

.fb-page-indicator {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.fb-page-indicator input {
    width: 50px;
    background: rgba(255, 255, 255, 0.05);
    border: var(--border-glass);
    border-radius: 4px;
    color: var(--text-main);
    text-align: center;
    padding: 0.3rem;
    font-family: var(--font-sans);
    font-size: 0.95rem;
}

.fb-page-indicator input:focus {
    outline: none;
    border-color: var(--color-primary);
}

.fb-zoom-controls {
    border-left: 1px solid rgba(255, 255, 255, 0.1);
    border-right: 1px solid rgba(255, 255, 255, 0.1);
    padding: 0 1rem;
}

#fb-zoom-level {
    font-size: 0.85rem;
    color: var(--text-muted);
    min-width: 45px;
    text-align: center;
}

/* Audiobook Section */
.audiobook-section {
    padding: 6rem 0;
    position: relative;
}

.audiobook-player-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: stretch;
}

.hidden-yt-player {
    position: absolute;
    top: 0;
    left: 0;
    width: 1px;
    height: 1px;
    opacity: 0;
    pointer-events: none;
}

/* Player Card Details */
.player-card {
    background-color: var(--bg-card);
    border: var(--border-glass);
    border-radius: 24px;
    padding: 2.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(15px);
}

.player-cover-area {
    position: relative;
    width: 200px;
    height: 300px;
    border-radius: 16px;
    overflow: hidden;
    margin-bottom: 2rem;
    box-shadow: 0 15px 30px rgba(0,0,0,0.5);
}

.player-album-art {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* Audio Visualizer Waves */
.player-visualizer {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 60px;
    background: linear-gradient(180deg, rgba(0,0,0,0) 0%, rgba(14,25,20,0.85) 100%);
    display: flex;
    justify-content: center;
    align-items: flex-end;
    gap: 6px;
    padding-bottom: 12px;
    opacity: 0;
    transition: opacity 0.5s ease;
}

.player-visualizer.playing {
    opacity: 1;
}

.player-visualizer .bar {
    width: 4px;
    background-color: var(--color-primary);
    border-radius: 2px 2px 0 0;
    animation: bounce-wave 1s ease infinite alternate;
}

.player-visualizer .bar:nth-child(1) { height: 10px; animation-delay: 0.1s; }
.player-visualizer .bar:nth-child(2) { height: 25px; animation-delay: 0.4s; }
.player-visualizer .bar:nth-child(3) { height: 35px; animation-delay: 0s; }
.player-visualizer .bar:nth-child(4) { height: 20px; animation-delay: 0.2s; }
.player-visualizer .bar:nth-child(5) { height: 12px; animation-delay: 0.5s; }

@keyframes bounce-wave {
    0% { transform: scaleY(0.3); }
    100% { transform: scaleY(1.2); }
}

.player-info-area {
    text-align: center;
    margin-bottom: 2rem;
    width: 100%;
}

.track-title {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    color: var(--text-main);
}

.track-author {
    color: var(--color-primary);
    font-weight: 500;
    font-size: 0.95rem;
    letter-spacing: 0.5px;
}

/* Timeline progress */
.player-timeline {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.progress-bar-container {
    flex-grow: 1;
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    position: relative;
    cursor: pointer;
}

.progress-bar-fill {
    height: 100%;
    width: 0%;
    background-color: var(--color-primary);
    border-radius: 4px;
    position: absolute;
    top: 0;
    left: 0;
}

.progress-handle {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--text-main);
    position: absolute;
    top: 50%;
    left: 0%;
    transform: translate(-50%, -50%);
    box-shadow: 0 0 10px rgba(0,0,0,0.5);
    cursor: grab;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.progress-bar-container:hover .progress-handle {
    opacity: 1;
}

/* Media buttons controls */
.player-controls {
    display: flex;
    align-items: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.btn-icon {
    background: transparent;
    border: none;
    font-size: 1.8rem;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition-quick);
}

.btn-icon:hover {
    color: var(--color-primary);
    transform: scale(1.1);
}

.btn-play-pause {
    width: 65px;
    height: 65px;
    border-radius: 50%;
    background-color: var(--color-primary);
    border: none;
    color: var(--bg-dark);
    font-size: 1.6rem;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 6px 18px var(--color-primary-glow);
    transition: var(--transition-smooth);
}

.btn-play-pause:hover {
    background-color: var(--color-primary-hover);
    transform: scale(1.08);
    box-shadow: 0 8px 25px rgba(212, 175, 55, 0.55);
}

.player-extra-controls {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid rgba(255,255,255,0.06);
    padding-top: 1.5rem;
}

.volume-container {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    width: 130px;
}

.btn-icon-small {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1rem;
    cursor: pointer;
}

.volume-bar {
    flex-grow: 1;
    height: 4px;
    background: rgba(255,255,255,0.1);
    border-radius: 2px;
    position: relative;
    cursor: pointer;
}

.volume-fill {
    height: 100%;
    background-color: var(--color-secondary);
    border-radius: 2px;
}

.speed-container select {
    background-color: rgba(255,255,255,0.05);
    border: var(--border-glass);
    border-radius: 6px;
    color: var(--text-main);
    padding: 0.3rem 0.6rem;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    outline: none;
    cursor: pointer;
}

/* Playlist card sidebar */
.playlist-card {
    background-color: var(--bg-card);
    border: var(--border-glass);
    border-radius: 24px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(15px);
}

.playlist-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    padding-bottom: 1.2rem;
    margin-bottom: 1rem;
}

.playlist-header h4 {
    font-size: 1.1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    color: var(--text-main);
}

.playlist-count {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.playlist-items {
    overflow-y: auto;
    max-height: 380px;
    padding-right: 0.5rem;
}

.playlist-items::-webkit-scrollbar {
    width: 5px;
}

.playlist-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.8rem;
    color: var(--text-muted);
    font-size: 0.95rem;
    padding: 3rem 0;
}

.playlist-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.9rem 1.2rem;
    border-radius: 12px;
    cursor: pointer;
    transition: var(--transition-quick);
    margin-bottom: 0.5rem;
    border: 1px solid transparent;
}

.playlist-item:hover {
    background-color: rgba(255,255,255,0.03);
    border-color: rgba(255, 255, 255, 0.05);
}

.playlist-item.active {
    background-color: rgba(197, 168, 128, 0.08);
    border-color: rgba(197, 168, 128, 0.2);
}

.track-index-title {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-grow: 1;
    overflow: hidden;
}

.track-num {
    font-size: 0.85rem;
    color: var(--color-primary);
    font-weight: 600;
    min-width: 20px;
}

.playlist-item.active .track-num {
    color: var(--color-primary-hover);
}

.track-name {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-main);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.playlist-item.active .track-name {
    color: var(--color-primary-hover);
    font-weight: 600;
}

.track-status-icon {
    color: var(--color-primary);
    font-size: 0.85rem;
    margin-left: 1rem;
}

/* Downloads Section */
.download-section {
    padding: 8rem 0;
    background: linear-gradient(180deg, #0d1612 0%, var(--bg-dark) 100%);
}

.download-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
    max-width: 900px;
    margin: 0 auto;
}

.download-card {
    background-color: var(--bg-card);
    border: var(--border-glass);
    border-radius: 20px;
    padding: 2.5rem;
    text-align: center;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3);
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.download-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary);
    box-shadow: 0 20px 40px rgba(197, 168, 128, 0.08);
}

.card-icon {
    font-size: 3rem;
    color: var(--color-primary);
    margin-bottom: 1.5rem;
}

.card-title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.8rem;
}

.card-desc {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 2rem;
    max-height: 80px;
    flex-grow: 1;
}

/* Footer styling */
.main-footer {
    padding: 3rem 0;
    border-top: var(--border-glass);
    background-color: #040706;
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.main-footer i {
    color: #e74c3c;
}

/* Fallback de clase JS para cuando falla o se bloquea el fullscreen nativo del navegador */
.flipbook-workdesk.is-fullscreen {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    z-index: 9999 !important;
}

/* Estilos cuando el workdesk está en Pantalla Completa (Clase JS y Pseudo-selector) */
.flipbook-workdesk.is-fullscreen,
.flipbook-workdesk:fullscreen {
    padding: 1.5rem !important;
    display: flex !important;
    flex-direction: column !important;
    justify-content: flex-start !important; /* Alinear elementos desde arriba */
    align-items: center !important;
    background: radial-gradient(circle, #162620 0%, #050807 100%) !important; /* Fondo premium oscuro-verdoso */
    width: 100vw !important;
    height: 100vh !important;
    max-width: 100vw !important;
    max-height: 100vh !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    overflow: hidden !important;
}

/* Colocar la barra de herramientas al principio (arriba del libro) en pantalla completa */
.flipbook-workdesk.is-fullscreen .flipbook-toolbar,
.flipbook-workdesk:fullscreen .flipbook-toolbar {
    order: -1 !important;
    margin-top: 0 !important;
    margin-bottom: 0.8rem !important;
    background: rgba(7, 11, 9, 0.92) !important;
    border: 1px solid rgba(255, 255, 255, 0.12) !important;
    border-radius: 30px !important;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.6) !important;
}

/* Maximizar la ventana de visualización en pantalla completa */
.flipbook-workdesk.is-fullscreen .flipbook-viewport,
.flipbook-workdesk:fullscreen .flipbook-viewport {
    max-width: 98vw !important;
    width: 98vw !important;
    height: 87vh !important; /* Ocupa el 87% de la altura útil de la pantalla */
    border-radius: 12px !important;
    background: rgba(0, 0, 0, 0.45) !important;
    box-shadow: inset 0 0 50px rgba(0, 0, 0, 0.8) !important;
    margin-bottom: 0 !important;
    border: 1px solid rgba(255, 255, 255, 0.05) !important;
}

/* Agrandar las flechas laterales en pantalla completa para que resalten */
.flipbook-workdesk.is-fullscreen .fb-nav-overlay,
.flipbook-workdesk:fullscreen .fb-nav-overlay {
    width: 85px !important;
    font-size: 3.5rem !important;
    color: rgba(255, 255, 255, 0.55) !important;
}
.flipbook-workdesk.is-fullscreen .fb-nav-overlay:hover,
.flipbook-workdesk:fullscreen .fb-nav-overlay:hover {
    color: var(--color-primary-hover) !important;
}

/* ==========================================================================
   DISEÑO RESPONSIVO (Media Queries)
   ========================================================================== */

@media (max-width: 1200px) {
    .flipbook-viewport {
        height: 600px;
    }
    .flipbook-container {
        width: 800px;
        height: 540px;
    }
}

@media (max-width: 1024px) {
    .hero-title {
        font-size: 3.5rem;
    }
    
    .flipbook-viewport {
        height: 500px;
    }
    .flipbook-container {
        width: 700px;
        height: 470px;
    }
    
    .audiobook-player-layout {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }

    .menu-toggle {
        display: block;
    }
    
    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background-color: var(--bg-dark);
        border-top: var(--border-glass);
        transition: 0.4s ease;
        z-index: 999;
    }
    
    .nav-menu.open {
        left: 0;
    }
    
    .nav-menu ul {
        flex-direction: column;
        padding: 3rem 2rem;
        gap: 1.5rem;
        align-items: center;
    }
    
    .nav-link {
        font-size: 1.2rem;
        width: 100%;
        justify-content: center;
        padding: 0.8rem 2rem;
    }

    /* === HERO SECTION MOBILE === */
    .hero-container {
        grid-template-columns: 1fr;
        gap: 2.5rem;
        text-align: center;
        padding-bottom: 4rem;
    }
    
    .hero-content {
        align-items: center;
    }
    
    .hero-title {
        font-size: 2.8rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-actions .btn {
        width: 100%;
    }
    
    .book-3d-wrapper {
        width: 220px;
        height: 330px;
    }

    /* === AUDIOBOOK SECTION MOBILE === */
    .audiobook-section {
        padding: 4rem 0;
    }

    .audiobook-player-layout {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .player-card {
        padding: 1.5rem 1rem;
        border-radius: 18px;
        overflow: hidden;
    }

    .player-cover-area {
        width: 140px;
        height: 210px;
        margin-bottom: 1.2rem;
        border-radius: 12px;
    }

    .player-info-area {
        margin-bottom: 1.2rem;
    }

    .track-title {
        font-size: 1.1rem;
        white-space: normal;
        line-height: 1.3;
        overflow: visible;
        text-overflow: unset;
    }

    .track-author {
        font-size: 0.85rem;
    }

    .player-timeline {
        gap: 0.6rem;
        margin-bottom: 1.2rem;
        font-size: 0.8rem;
    }

    .player-controls {
        gap: 1.5rem;
        margin-bottom: 1.5rem;
    }

    .btn-icon {
        font-size: 1.5rem;
    }

    .btn-play-pause {
        width: 55px;
        height: 55px;
        font-size: 1.3rem;
    }

    .player-extra-controls {
        flex-direction: row;
        gap: 1rem;
        padding-top: 1rem;
    }

    .volume-container {
        width: 100px;
        gap: 0.4rem;
    }

    .speed-container select {
        font-size: 0.8rem;
        padding: 0.25rem 0.4rem;
    }

    /* === PLAYLIST CARD MOBILE === */
    .playlist-card {
        padding: 1rem;
        border-radius: 18px;
    }

    .playlist-header {
        padding-bottom: 0.8rem;
        margin-bottom: 0.8rem;
    }

    .playlist-header h4 {
        font-size: 1rem;
    }

    .playlist-items {
        max-height: 320px;
    }

    .playlist-item {
        padding: 0.7rem 0.6rem;
        margin-bottom: 0.3rem;
        border-radius: 8px;
    }

    .track-index-title {
        gap: 0.5rem;
    }

    .track-name {
        white-space: normal;
        font-size: 0.85rem;
        line-height: 1.35;
    }

    .track-num {
        font-size: 0.8rem;
        min-width: 18px;
    }

    /* === SECTIONS MOBILE === */
    .section-header {
        margin-bottom: 2.5rem;
    }

    .section-title {
        font-size: 2.4rem;
    }

    .section-subtitle {
        font-size: 0.95rem;
    }

    .download-grid {
        grid-template-columns: 1fr;
    }

    .download-section {
        padding: 4rem 0;
    }

    .download-card {
        padding: 2rem 1.5rem;
    }
    
    .footer-container {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    /* Flipbook responsive (Single-Page Mode) */
    .flipbook-workdesk {
        padding: 1.5rem;
    }
    
    .flipbook-viewport {
        height: 450px;
    }
    
    .flipbook-container {
        width: 340px;
        height: 400px;
    }
    
    /* Modify page turning for single-page layout */
    .flipbook-container.single-page .sheet {
        left: 0;
        width: 100%;
        transform-origin: left center;
    }
    
    /* Sliding animation instead of 3D flip for single-page */
    .flipbook-container.single-page .sheet.flipped {
        transform: translateX(-110%) rotateY(0deg);
        opacity: 0;
    }
    
    .flipbook-container.single-page .page-face.back {
        display: none;
    }
    
    .flipbook-container.single-page .page-face.front {
        border-radius: 8px;
    }

    .flipbook-container.closed-left,
    .flipbook-container.closed-right {
        transform: translateX(0);
    }
}

@media (max-width: 480px) {
    .section-title {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 2.4rem;
    }

    .book-3d-wrapper {
        width: 180px;
        height: 270px;
    }

    .player-card {
        padding: 1.2rem 0.8rem;
    }

    .player-cover-area {
        width: 120px;
        height: 180px;
    }

    .track-title {
        font-size: 1rem;
    }

    .player-controls {
        gap: 1.2rem;
        margin-bottom: 1.2rem;
    }

    .btn-play-pause {
        width: 50px;
        height: 50px;
        font-size: 1.2rem;
    }

    .btn-icon {
        font-size: 1.3rem;
    }

    .volume-container {
        width: 80px;
    }

    .flipbook-container {
        width: 280px;
        height: 360px;
    }
    
    .flipbook-toolbar {
        padding: 0.8rem 1rem;
        border-radius: 20px;
        gap: 0.8rem;
    }
    
    .toolbar-group button {
        padding: 0.4rem 0.6rem;
        font-size: 0.8rem;
    }
    
    .fb-zoom-controls {
        display: none;
    }
}

/* ==========================================================================
   BOTÓN FLOTANTE DE WHATSAPP
   ========================================================================== */
.whatsapp-float {
    position: fixed;
    bottom: 2.5rem;
    right: 2.5rem;
    background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
    color: #ffffff;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 2.2rem;
    box-shadow: 0 4px 15px rgba(37, 211, 102, 0.4);
    z-index: 9999;
    transition: var(--transition-smooth);
    text-decoration: none;
}

.whatsapp-float:hover {
    transform: scale(1.1) translateY(-3px);
    box-shadow: 0 8px 25px rgba(37, 211, 102, 0.6);
    color: #ffffff;
}

.whatsapp-tooltip {
    position: absolute;
    right: 75px;
    background-color: var(--bg-glass);
    backdrop-filter: blur(8px);
    border: var(--border-glass);
    color: var(--text-main);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 500;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transform: translateX(15px);
    transition: var(--transition-smooth);
    pointer-events: none;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

.whatsapp-float:hover .whatsapp-tooltip {
    opacity: 1;
    visibility: visible;
    transform: translateX(0);
}

@media (max-width: 768px) {
    .whatsapp-float {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 50px;
        height: 50px;
        font-size: 1.8rem;
    }
    
    .whatsapp-tooltip {
        display: none;
    }
}