/* ═══════════════════════════════════════════════════════════
   Biblioteca Sonora — Design System
   ═══════════════════════════════════════════════════════════ */

:root {
    /* Colors */
    --bg: #0a0a0f;
    --bg-raised: #111118;
    --bg-card: #16161f;
    --bg-card-hover: #1c1c28;
    --surface: #1e1e2a;
    --border: rgba(255, 255, 255, 0.06);
    --border-hover: rgba(255, 255, 255, 0.12);

    --text: #e8e6f0;
    --text-secondary: #9490a8;
    --text-muted: #5e5a72;

    --accent: #c9a96e;
    --accent-light: #dfc48f;
    --accent-dim: rgba(201, 169, 110, 0.15);
    --accent-glow: rgba(201, 169, 110, 0.25);

    --success: #5cb88a;
    --warning: #d4a843;

    /* Typography */
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

    /* Spacing */
    --nav-height: 64px;
    --section-padding: 100px;
    --card-radius: 16px;
    --radius-sm: 8px;
    --radius-md: 12px;

    /* Transitions */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ─── RESET ──────────────────────────────────────────── */

*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    max-width: 100%;
    display: block;
}

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
    color: inherit;
}

/* ─── NAV ────────────────────────────────────────────── */

#main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    height: var(--nav-height);
    background: rgba(10, 10, 15, 0.7);
    backdrop-filter: blur(20px) saturate(1.6);
    -webkit-backdrop-filter: blur(20px) saturate(1.6);
    border-bottom: 1px solid var(--border);
    transition: background 0.4s var(--ease-smooth);
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 32px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--accent);
    letter-spacing: -0.01em;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-link {
    font-size: 0.875rem;
    font-weight: 400;
    color: var(--text-secondary);
    transition: color 0.3s var(--ease-smooth);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width 0.3s var(--ease-out);
}

.nav-link:hover {
    color: var(--text);
}

.nav-link:hover::after {
    width: 100%;
}

/* ─── HERO ───────────────────────────────────────────── */

#hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--nav-height) + 40px) 32px 60px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse 60% 50% at 50% 0%, rgba(201, 169, 110, 0.08) 0%, transparent 70%),
        radial-gradient(ellipse 40% 60% at 20% 80%, rgba(90, 60, 140, 0.06) 0%, transparent 60%),
        radial-gradient(ellipse 40% 60% at 80% 80%, rgba(60, 100, 140, 0.05) 0%, transparent 60%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    max-width: 720px;
    text-align: center;
    animation: heroFadeIn 1.2s var(--ease-out) both;
}

@keyframes heroFadeIn {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20% { transform: translateX(-10px); }
    40% { transform: translateX(10px); }
    60% { transform: translateX(-6px); }
    80% { transform: translateX(6px); }
}

.hero-badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent);
    background: var(--accent-dim);
    border: 1px solid rgba(201, 169, 110, 0.2);
    padding: 6px 16px;
    border-radius: 100px;
    margin-bottom: 28px;
    animation: heroFadeIn 1.2s var(--ease-out) 0.2s both;
}

#hero-title {
    font-family: var(--font-display);
    font-size: clamp(2.4rem, 5vw, 3.8rem);
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin-bottom: 20px;
    color: var(--text);
    animation: heroFadeIn 1.2s var(--ease-out) 0.3s both;
}

#hero-title em {
    font-style: italic;
    color: var(--accent);
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 560px;
    margin: 0 auto 36px;
    line-height: 1.7;
    animation: heroFadeIn 1.2s var(--ease-out) 0.4s both;
}

.hero-actions {
    display: flex;
    gap: 14px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 56px;
    animation: heroFadeIn 1.2s var(--ease-out) 0.5s both;
}

.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
    animation: heroFadeIn 1.2s var(--ease-out) 0.7s both;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    color: var(--text);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--border);
}

.hero-scroll-hint {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--text-muted);
    animation: bounce 2.5s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(8px); }
}

/* ─── BUTTONS ────────────────────────────────────────── */

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: 100px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s var(--ease-out);
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent), #b8944f);
    color: #0a0a0f;
    box-shadow: 0 4px 20px rgba(201, 169, 110, 0.2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(201, 169, 110, 0.35);
}

.btn-ghost {
    border: 1px solid var(--border-hover);
    color: var(--text-secondary);
}

.btn-ghost:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-dim);
}

/* ─── SECTIONS ───────────────────────────────────────── */

section {
    padding: var(--section-padding) 0;
}

.section-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 32px;
}

.section-header {
    text-align: center;
    margin-bottom: 56px;
}

.section-header h2 {
    font-family: var(--font-display);
    font-size: clamp(1.8rem, 3vw, 2.6rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 1.05rem;
}

/* ─── FILTERS ────────────────────────────────────────── */

.filters {
    display: flex;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 24px;
}

.filter-btn {
    padding: 8px 20px;
    border-radius: 100px;
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    background: transparent;
    transition: all 0.3s var(--ease-out);
}

.filter-btn:hover {
    border-color: var(--border-hover);
    color: var(--text);
}

.filter-btn.active {
    background: var(--accent-dim);
    border-color: var(--accent);
    color: var(--accent);
}

/* ─── SEARCH ─────────────────────────────────────────── */

.search-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    max-width: 480px;
    margin: 0 auto 48px;
    padding: 12px 20px;
    background: var(--bg-raised);
    border: 1px solid var(--border);
    border-radius: 100px;
    transition: border-color 0.3s var(--ease-smooth);
}

.search-bar:focus-within {
    border-color: var(--accent);
}

.search-bar svg {
    color: var(--text-muted);
    flex-shrink: 0;
}

.search-bar input {
    flex: 1;
    background: none;
    border: none;
    outline: none;
    color: var(--text);
    font-size: 0.9rem;
    font-family: var(--font-body);
}

.search-bar input::placeholder {
    color: var(--text-muted);
}

/* ─── BOOKS GRID ─────────────────────────────────────── */

.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 28px;
}

.book-card {
    position: relative;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--card-radius);
    overflow: hidden;
    cursor: pointer;
    transition: all 0.4s var(--ease-out);
    animation: cardFadeIn 0.6s var(--ease-out) both;
}

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

.book-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    transform: translateY(-6px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

.book-cover-wrap {
    position: relative;
    aspect-ratio: 3/4;
    overflow: hidden;
}

.book-cover-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s var(--ease-out);
}

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

.book-cover-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(10, 10, 15, 0.85) 0%, transparent 50%);
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: 20px;
    opacity: 0;
    transition: opacity 0.4s var(--ease-smooth);
}

.book-card:hover .book-cover-overlay {
    opacity: 1;
}

.book-play-btn {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    transform: translateY(10px);
    transition: transform 0.4s var(--ease-out);
    box-shadow: 0 4px 20px rgba(201, 169, 110, 0.3);
}

.book-card:hover .book-play-btn {
    transform: translateY(0);
}

.book-play-btn svg {
    color: #0a0a0f;
    margin-left: 2px;
}

.book-info {
    padding: 18px 20px 20px;
}

.book-genre {
    font-size: 0.68rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent);
    margin-bottom: 8px;
}

.book-title {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 4px;
    color: var(--text);
}

.book-author {
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-bottom: 14px;
}

.book-meta {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.book-meta-item {
    display: flex;
    align-items: center;
    gap: 5px;
}

.book-meta-item svg {
    width: 14px;
    height: 14px;
}

.no-results {
    text-align: center;
    color: var(--text-muted);
    font-size: 1rem;
    padding: 60px 0;
}

/* ─── FEATURES ───────────────────────────────────────── */

#como-funciona {
    background: var(--bg-raised);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
}

.feature-card {
    padding: 32px 28px;
    border-radius: var(--card-radius);
    background: var(--bg-card);
    border: 1px solid var(--border);
    transition: all 0.4s var(--ease-out);
}

.feature-card:hover {
    border-color: var(--accent);
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

.feature-icon {
    width: 52px;
    height: 52px;
    border-radius: var(--radius-md);
    background: var(--accent-dim);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: var(--accent);
}

.feature-card h3 {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.65;
}

/* ─── ABOUT ──────────────────────────────────────────── */

.about-inner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h2 {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    font-weight: 700;
    margin-bottom: 20px;
}

.about-text p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 16px;
}

.about-waveform {
    display: flex;
    align-items: center;
    justify-content: center;
}

#waveform-canvas {
    width: 100%;
    max-width: 400px;
    height: 200px;
    border-radius: var(--card-radius);
    background: var(--bg-card);
    border: 1px solid var(--border);
}

/* ─── FOOTER ─────────────────────────────────────────── */

#footer {
    padding: 40px 0;
    border-top: 1px solid var(--border);
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-display);
    font-weight: 600;
    color: var(--accent);
    font-size: 0.95rem;
}

.footer-copy {
    font-size: 0.78rem;
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    font-size: 0.82rem;
    color: var(--text-secondary);
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--accent);
}

/* ─── MODAL ──────────────────────────────────────────── */

.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 200;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 32px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s var(--ease-smooth);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-card {
    position: relative;
    max-width: 700px;
    width: 100%;
    background: var(--bg-raised);
    border: 1px solid var(--border);
    border-radius: 20px;
    overflow: hidden;
    transform: translateY(20px) scale(0.97);
    transition: transform 0.4s var(--ease-out);
}

.modal-overlay.active .modal-card {
    transform: translateY(0) scale(1);
}

.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    z-index: 10;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all 0.3s;
}

.modal-close:hover {
    background: rgba(0, 0, 0, 0.8);
    color: var(--text);
}

.modal-body {
    display: flex;
    gap: 0;
}

.modal-cover {
    width: 240px;
    min-height: 340px;
    object-fit: cover;
    flex-shrink: 0;
}

.modal-info {
    padding: 32px 28px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.modal-genre {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent);
    margin-bottom: 8px;
}

.modal-info h2 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 6px;
}

.modal-author {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 16px;
}

.modal-description {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.65;
    margin-bottom: 20px;
}

.modal-meta {
    display: flex;
    gap: 20px;
    margin-bottom: 24px;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.meta-item svg {
    color: var(--accent);
}

.modal-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.btn-download {
    font-size: 0.85rem;
    padding: 11px 24px;
}

.btn-preview {
    font-size: 0.85rem;
    padding: 11px 20px;
}

/* ─── RESPONSIVE ─────────────────────────────────────── */

@media (max-width: 768px) {
    .nav-links { display: none; }

    .hero-stats { gap: 20px; }
    .stat-number { font-size: 1.5rem; }

    .books-grid { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; }

    .about-inner { grid-template-columns: 1fr; gap: 40px; }

    .modal-body { flex-direction: column; }
    .modal-cover { width: 100%; min-height: 200px; max-height: 240px; }

    .footer-inner { flex-direction: column; text-align: center; }
}

@media (max-width: 480px) {
    .section-inner { padding: 0 20px; }
    .books-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
    .book-info { padding: 14px 14px 16px; }
    .book-title { font-size: 0.95rem; }
}

/* ─── AUTH GATE ───────────────────────────────────────── */

.auth-gate {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: var(--bg);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s var(--ease-out), visibility 0.5s;
}

.auth-gate.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.auth-card {
    text-align: center;
    max-width: 380px;
    width: 100%;
    padding: 48px 36px;
    background: var(--bg-raised);
    border: 1px solid var(--border);
    border-radius: 20px;
    animation: heroFadeIn 0.8s var(--ease-out) both;
}

.auth-icon {
    color: var(--accent);
    margin-bottom: 20px;
}

.auth-card h2 {
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 700;
    margin-bottom: 6px;
    color: var(--text);
}

.auth-card > p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 28px;
}

#auth-form {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

#auth-input {
    width: 100%;
    padding: 13px 18px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--text);
    font-size: 0.9rem;
    font-family: var(--font-body);
    outline: none;
    transition: border-color 0.3s;
    text-align: center;
    letter-spacing: 0.1em;
}

#auth-input:focus {
    border-color: var(--accent);
}

#auth-input::placeholder {
    color: var(--text-muted);
    letter-spacing: 0;
}

#auth-form .btn {
    width: 100%;
    justify-content: center;
}

.auth-error {
    font-size: 0.8rem;
    color: #e05555;
    margin-top: 12px;
    min-height: 1.2em;
}