html {
    scroll-behavior: smooth;
}

/* 4. Indicador de lectura superior */
#reading-progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 4px;
    background: linear-gradient(90deg, #0090A8, #10b981);
    z-index: 1000;
    width: 0%;
    transition: width 0.1s ease;
}

.material-symbols-outlined {
    font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
    transition: all 0.3s ease;
}

.fill-icon {
    font-variation-settings: 'FILL' 1;
}

.stat-card {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.stat-card:hover {
    transform: translateY(-4px);
    border-color: rgba(0, 144, 168, 0.4);
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
}

.dark .stat-card:hover {
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
    border-color: rgba(0, 144, 168, 0.3);
}

/* 2. Efecto de Brillo (Glint) */
@keyframes glint {
    0% {
        transform: translateX(-150%) skewX(-25deg);
    }

    50% {
        transform: translateX(150%) skewX(-25deg);
    }

    100% {
        transform: translateX(150%) skewX(-25deg);
    }
}

.glint-effect::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 40%;
    height: 100%;
    background: linear-gradient(to right,
            transparent,
            rgba(255, 255, 255, 0.3),
            transparent);
    animation: glint 5s infinite ease-in-out;
    pointer-events: none;
}

/* 1. Scroll Spy Mejorado: Clases de resaltado */
.nav-link.active-section {
    background: rgba(0, 144, 168, 0.1);
    color: #0090A8 !important;
    box-shadow: inset 4px 0 0 #0090A8;
}

.dark .nav-link.active-section {
    background: rgba(16, 185, 129, 0.1);
    color: #10b981 !important;
    box-shadow: inset 4px 0 0 #10b981;
}

/* 6. Botón Volver Arriba */
#back-to-top {
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

#back-to-top.show {
    opacity: 1;
    visibility: visible;
}

/* 3. Estilos de Modales */
#details-modal {
    backdrop-filter: blur(8px);
    transition: all 0.3s ease;
}

/* --- NUEVAS ANIMACIONES DE NAVEGACIÓN --- */
.nav-link {
    position: relative;
    z-index: 10;
}

#nav-indicator {
    position: absolute;
    left: 12px;
    right: 12px;
    height: 44px;
    background: rgba(0, 144, 168, 0.05);
    border-radius: 12px;
    z-index: 0;
    transition: all 0.4s cubic-bezier(0.18, 0.89, 0.32, 1.1);
    pointer-events: none;
    opacity: 0;
}

.nav-link:hover .material-symbols-outlined {
    transform: scale(1.15) rotate(-5deg);
}

.report-cover-preview {
    transform: perspective(1000px) rotateY(-5deg) rotateX(2deg);
    box-shadow: 10px 10px 25px rgba(0, 0, 0, 0.3);
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.report-cover-preview:hover {
    transform: perspective(1000px) rotateY(0deg) rotateX(0deg) scale(1.05);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4);
}

.dark ::-webkit-scrollbar {
    width: 8px;
}

.dark ::-webkit-scrollbar-track {
    background: #0f1712;
}

.dark ::-webkit-scrollbar-thumb {
    background: #2d3a31;
    border-radius: 10px;
}

.dark ::-webkit-scrollbar-thumb:hover {
    background: #0090A8;
}

#welcome-overlay {
    backdrop-filter: blur(12px);
    transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

#welcome-modal {
    transition: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.modal-hidden {
    opacity: 0;
    pointer-events: none;
}

.modal-scale-down {
    transform: scale(0.9);
}

/* --- FLIPBOOK STYLES --- */
#flipbook-container {
    background-color: transparent;
    transition: all 0.5s ease;
    margin: 0 auto;
}

#flipbook {
    margin: 0 auto;
}

.flipbook-page {
    background-color: white;
}

#flipbook canvas {
    display: block;
    max-width: 100%;
    height: auto;
}

@media (max-width: 1024px) {
    #flipbook-container {
        max-width: 90vw;
    }
}

@media (max-width: 768px) {
    #flipbook-container {
        aspect-ratio: auto;
        height: 70vh;
        max-width: 100vw;
    }
}