/* Variables de color y tipografía */
:root {
    /* Paleta principal oscura moderna */
    --color-primary: #1E293B;
    --color-secondary: #334155;
    --color-accent-1: #475569;
    --color-accent-2: #0F172A;
    --color-accent-3: #6366F1;
    
    /* Colores para texto */
    --text-primary: #F8FAFC;
    --text-secondary: #CBD5E1;
    --text-links: #94A3B8;
    --text-links-hover: #6366F1;
    
    /* Tipografía */
    --font-titles: 'Playfair Display', serif;
    --font-content: 'Source Serif Pro', 'Libre Baskerville', serif;
    --font-ui: 'Work Sans', 'Montserrat', sans-serif;
    
    /* Transiciones */
    --transition-standard: all 0.3s ease;
    
    /* Espaciado */
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* Sombras */
    --shadow-soft: 0 3px 10px rgba(0,0,0,0.1);
    --shadow-medium: 0 5px 15px rgba(0,0,0,0.15);
    --shadow-hard: 0 8px 20px rgba(0,0,0,0.2);
}

/* Estilos generales */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@400;500;600;700&family=Source+Serif+Pro:wght@400;600&family=Work+Sans:wght@400;500;600&family=Montserrat:wght@400;500;600&family=Libre+Baskerville:wght@400;700&display=swap');

body {
    font-family: var(--font-content);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--color-primary);
    transition: var(--transition-standard);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
header {
    background: linear-gradient(to bottom, var(--color-primary), var(--color-accent-2));
    color: var(--text-primary);
    padding: var(--spacing-lg) 0;
    box-shadow: var(--shadow-medium);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

header h1 {
    margin-bottom: var(--spacing-md);
    font-weight: 700;
    font-family: var(--font-titles);
    letter-spacing: 1px;
    display: flex;
    align-items: center;
}

header h1::before {
    content: "✉️";
    margin-right: var(--spacing-sm);
    font-size: 0.9em;
}

nav ul {
    list-style: none;
    display: flex;
}

nav ul li {
    margin-right: var(--spacing-lg);
}

nav ul li a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 18px;
    font-family: var(--font-ui);
    transition: var(--transition-standard);
    padding: var(--spacing-sm) 0;
    position: relative;
}

nav ul li a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--color-accent-3);
    transition: var(--transition-standard);
}

nav ul li a:hover, nav ul li a.active {
    color: var(--text-primary);
}

nav ul li a:hover::after, nav ul li a.active::after {
    width: 100%;
}

/* Main content */
main {
    padding: var(--spacing-xl) 0;
    min-height: calc(100vh - 200px);
    animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.intro {
    margin-bottom: var(--spacing-xl);
    text-align: center;
    padding: var(--spacing-lg) var(--spacing-md);
}

.intro h2 {
    font-family: var(--font-titles);
    font-size: 32px;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.intro p {
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto;
    color: var(--text-secondary);
}

/* Cartas */
.cartas-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.carta-card {
    background: var(--color-secondary);
    border-radius: 12px;
    box-shadow: var(--shadow-soft);
    overflow: hidden;
    transition: var(--transition-standard);
    position: relative;
    border: 1px solid rgba(71, 85, 105, 0.2);
    opacity: 0;
    transform: translateY(20px);
    animation: cardFadeIn 0.6s forwards;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.carta-card::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: 40px;
    height: 40px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2394A3B8' stroke-width='1' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M21 5H3a2 2 0 0 0-2 2v10a2 2 0 0 0 2 2h18a2 2 0 0 0 2-2V7a2 2 0 0 0-2-2Z'/%3E%3Cpath d='m3 7 9 6 9-6'/%3E%3C/svg%3E");
    background-size: 20px;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0.3;
    pointer-events: none;
}

.carta-card:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-hard);
    border-color: rgba(99, 102, 241, 0.2);
}

.carta-card:hover::after {
    opacity: 0.5;
}

.carta-header {
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid rgba(71, 85, 105, 0.1);
    background: linear-gradient(to right, rgba(99, 102, 241, 0.05), transparent);
}

.carta-titulo {
    font-size: 22px;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-family: var(--font-titles);
    line-height: 1.3;
}

.carta-fecha {
    font-size: 14px;
    color: var(--text-secondary);
    font-style: italic;
    font-family: var(--font-ui);
    display: inline-block;
    padding: 4px 10px;
    background-color: rgba(15, 23, 42, 0.2);
    border-radius: 20px;
    margin-top: 4px;
}

.carta-preview {
    padding: var(--spacing-lg);
    height: 120px;
    overflow: hidden;
    position: relative;
    color: var(--text-secondary);
    line-height: 1.7;
    flex-grow: 1;
    font-family: var(--font-content);
}

.carta-preview::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 80px;
    background: linear-gradient(transparent, var(--color-secondary));
}

/* Carta metadata y tiempo de lectura */
.carta-metadata {
    padding: 0 var(--spacing-lg);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    margin-top: var(--spacing-md);
    margin-bottom: 5px;
    gap: 8px;
    color: var(--text-secondary);
    font-size: 14px;
    font-family: var(--font-ui);
}

.tiempo-lectura {
    display: flex;
    align-items: center;
    margin-right: var(--spacing-md);
    font-size: 13px;
    color: var(--text-secondary);
    background-color: rgba(15, 23, 42, 0.15);
    padding: 3px 8px;
    border-radius: 15px;
}

.tiempo-lectura::before {
    content: "⏱️";
    margin-right: 5px;
    font-size: 11px;
}

.carta-footer {
    padding: var(--spacing-md) var(--spacing-lg);
    text-align: right;
    border-top: 1px solid rgba(71, 85, 105, 0.1);
    background: linear-gradient(to right, transparent, rgba(99, 102, 241, 0.05));
    margin-top: auto;
}

.carta-link {
    color: var(--text-links);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-standard);
    font-family: var(--font-ui);
    display: inline-flex;
    align-items: center;
    padding: 6px 12px;
    border-radius: 20px;
    background-color: rgba(15, 23, 42, 0.1);
}

.carta-link::after {
    content: "→";
    margin-left: 5px;
    transition: var(--transition-standard);
}

.carta-link:hover {
    color: var(--text-links-hover);
    background-color: rgba(99, 102, 241, 0.1);
}

.carta-link:hover::after {
    transform: translateX(3px);
}

/* Etiquetas de categorías */
.etiquetas {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.etiqueta {
    background-color: rgba(71, 85, 105, 0.2);
    color: var(--text-secondary);
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-family: var(--font-ui);
    transition: var(--transition-standard);
    border: 1px solid transparent;
}

.etiqueta:hover {
    background-color: rgba(99, 102, 241, 0.1);
    border-color: rgba(99, 102, 241, 0.2);
    color: var(--text-links-hover);
}

/* Detalle de carta */
.carta-detalle {
    background: var(--color-secondary);
    padding: var(--spacing-xl);
    border-radius: 15px;
    box-shadow: var(--shadow-medium);
    margin-bottom: var(--spacing-lg);
    position: relative;
    background-image: url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI1IiBoZWlnaHQ9IjUiPgo8cmVjdCB3aWR0aD0iNSIgaGVpZ2h0PSI1IiBmaWxsPSIjMzM0MTU1Ij48L3JlY3Q+CjxwYXRoIGQ9Ik0wIDVMNSAwWk02IDRMNCA2Wk0tMSAxTDEgLTFaIiBzdHJva2U9IiMzRDRBNjAiIHN0cm9rZS13aWR0aD0iMSI+PC9wYXRoPgo8L3N2Zz4=');
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
    border: 1px solid rgba(71, 85, 105, 0.15);
}

.carta-detalle::before {
    content: "";
    position: absolute;
    bottom: 20px;
    right: 20px;
    width: 150px;
    height: 150px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23CBD5E1' stroke-width='0.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M21 5H3a2 2 0 0 0-2 2v10a2 2 0 0 0 2 2h18a2 2 0 0 0 2-2V7a2 2 0 0 0-2-2Z'/%3E%3Cpath d='m3 7 9 6 9-6'/%3E%3C/svg%3E");
    background-size: contain;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0.05;
    z-index: 0;
    transform: rotate(-5deg);
}

.carta-titulo-detalle {
    font-size: 36px;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    font-family: var(--font-titles);
    position: relative;
    z-index: 1;
}

.carta-fecha-detalle {
    font-size: 16px;
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: var(--spacing-lg);
    display: block;
    font-family: var(--font-ui);
    position: relative;
    z-index: 1;
}

.carta-contenido-detalle {
    white-space: pre-wrap;
    line-height: 1.8;
    color: var(--text-primary);
    font-size: 18px;
    position: relative;
    z-index: 1;
}

.carta-navegacion {
    display: flex;
    justify-content: space-between;
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease 0.1s, transform 0.3s ease 0.1s;
}

.nav-carta {
    color: var(--text-links);
    text-decoration: none;
    font-family: var(--font-ui);
    display: flex;
    align-items: center;
    transition: var(--transition-standard);
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-accent-1);
    border-radius: 4px;
}

.nav-carta:hover {
    color: var(--text-links-hover);
    background-color: rgba(99, 102, 241, 0.1);
}

.nav-carta-anterior::before {
    content: "←";
    margin-right: 5px;
}

.nav-carta-siguiente::after {
    content: "→";
    margin-left: 5px;
}

.carta-acciones {
    display: flex;
    justify-content: flex-end;
    margin-bottom: var(--spacing-xl);
}

/* Formularios */
.form-section {
    background: var(--color-secondary);
    padding: var(--spacing-xl);
    border-radius: 8px;
    box-shadow: var(--shadow-medium);
}

.form-section h2 {
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
    font-family: var(--font-titles);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
    font-family: var(--font-ui);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--color-accent-1);
    border-radius: 4px;
    font-size: 16px;
    background-color: var(--color-accent-2);
    color: var(--text-primary);
    font-family: var(--font-content);
    transition: var(--transition-standard);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--color-accent-3);
    outline: none;
    box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.2);
}

.form-group textarea {
    resize: vertical;
    min-height: 200px;
}

/* Botones */
.btn-primary,
.btn-secondary,
.btn-danger {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    font-family: var(--font-ui);
    cursor: pointer;
    transition: var(--transition-standard);
}

.btn-primary {
    background-color: var(--color-accent-3);
    color: white;
}

.btn-primary:hover {
    background-color: #5253cc;
    transform: translateY(-2px);
    box-shadow: var(--shadow-soft);
}

.btn-secondary {
    background-color: var(--color-accent-1);
    color: white;
    margin-right: 10px;
}

.btn-secondary:hover {
    background-color: #394454;
    transform: translateY(-2px);
    box-shadow: var(--shadow-soft);
}

.btn-danger {
    background-color: #e74c3c;
    color: white;
}

.btn-danger:hover {
    background-color: #c0392b;
    transform: translateY(-2px);
    box-shadow: var(--shadow-soft);
}

/* Mensajes */
.mensaje {
    padding: 15px;
    margin-top: 20px;
    border-radius: 4px;
    font-family: var(--font-ui);
}

.mensaje.exito {
    background-color: rgba(39, 174, 96, 0.2);
    border: 1px solid #27ae60;
    color: #2ecc71;
}

.mensaje.error {
    background-color: rgba(231, 76, 60, 0.2);
    border: 1px solid #e74c3c;
    color: #e74c3c;
}

/* Footer */
footer {
    background-color: var(--color-accent-2);
    color: var(--text-secondary);
    padding: var(--spacing-lg) 0;
    text-align: center;
    font-family: var(--font-ui);
    border-top: 1px solid var(--color-accent-1);
}

/* Estado de carga */
.cargando {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-secondary);
    font-style: italic;
    font-family: var(--font-ui);
}

/* Botón Volver Arriba */
.volver-arriba {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background-color: var(--color-accent-3);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    font-size: 24px;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-standard);
    box-shadow: var(--shadow-medium);
    z-index: 1000;
}

.volver-arriba.visible {
    opacity: 1;
    visibility: visible;
}

.volver-arriba:hover {
    background-color: #5253cc;
    transform: translateY(-3px);
}

/* Modo oscuro/claro */
.modo-toggle {
    position: fixed;
    bottom: 30px;
    left: 30px;
    width: 50px;
    height: 50px;
    background-color: var(--color-accent-1);
    color: var(--text-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 20px;
    box-shadow: var(--shadow-medium);
    z-index: 1000;
    transition: var(--transition-standard);
}

.modo-toggle:hover {
    background-color: var(--color-accent-3);
    transform: translateY(-3px);
}

/* Etiquetas de categorías */
.etiquetas {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.etiqueta {
    background-color: var(--color-accent-1);
    color: var(--text-secondary);
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-family: var(--font-ui);
}

/* Buscador */
.buscador {
    margin-bottom: var(--spacing-xl);
    position: relative;
}

.buscador input {
    width: 100%;
    padding: 12px 15px;
    padding-left: 40px;
    border: 1px solid var(--color-accent-1);
    border-radius: 8px;
    background-color: var(--color-accent-2);
    color: var(--text-primary);
    font-family: var(--font-ui);
    font-size: 16px;
    transition: var(--transition-standard);
}

.buscador input:focus {
    border-color: var(--color-accent-3);
    outline: none;
    box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.2);
}

.buscador::before {
    content: "🔍";
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

/* Media Queries */
@media (max-width: 768px) {
    .cartas-container {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
    
    header .container {
        flex-direction: column;
        align-items: flex-start;
    }
    
    nav ul {
        width: 100%;
        margin-top: var(--spacing-md);
    }
    
    .carta-detalle {
        padding: var(--spacing-lg);
    }
    
    .volver-arriba, .modo-toggle {
        width: 40px;
        height: 40px;
        font-size: 18px;
    }
}

@media (max-width: 480px) {
    .cartas-container {
        grid-template-columns: 1fr;
    }
    
    header h1 {
        font-size: 24px;
    }
    
    nav ul li a {
        font-size: 16px;
    }
    
    .carta-titulo-detalle {
        font-size: 28px;
    }
    
    .carta-contenido-detalle {
        font-size: 16px;
    }
    
    .btn-primary, .btn-secondary, .btn-danger {
        padding: 8px 16px;
        font-size: 14px;
    }
    
    .volver-arriba {
        bottom: 20px;
        right: 20px;
    }
    
    .modo-toggle {
        bottom: 20px;
        left: 20px;
    }
}

/* Modo claro */
.modo-claro {
    --color-primary: #F8FAFC;
    --color-secondary: #F1F5F9;
    --color-accent-1: #E2E8F0;
    --color-accent-2: #CBD5E1;
    --color-accent-3: #6366F1;
    
    --text-primary: #0F172A;
    --text-secondary: #334155;
    --text-links: #475569;
    --text-links-hover: #6366F1;
}

/* Efectos de transición para cartas */
.carta-detalle.mostrado {
    opacity: 1;
    transform: translateY(0);
}

.carta-detalle.transicion-salida {
    opacity: 0;
    transform: translateX(-30px);
}

/* Ajustes para la navegación de cartas */
.carta-detalle.mostrado + .carta-navegacion {
    opacity: 1;
    transform: translateY(0);
}

/* Animación de entrada para las cartas en la página principal */
@keyframes cardFadeIn {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Ajuste de animación en cascada para las tarjetas */
.carta-card:nth-child(1) { animation-delay: 0.1s; }
.carta-card:nth-child(2) { animation-delay: 0.2s; }
.carta-card:nth-child(3) { animation-delay: 0.3s; }
.carta-card:nth-child(4) { animation-delay: 0.4s; }
.carta-card:nth-child(5) { animation-delay: 0.5s; }
.carta-card:nth-child(6) { animation-delay: 0.6s; }
.carta-card:nth-child(7) { animation-delay: 0.7s; }
.carta-card:nth-child(8) { animation-delay: 0.8s; }
.carta-card:nth-child(9) { animation-delay: 0.9s; }
.carta-card:nth-child(10) { animation-delay: 1s; }

/* Efecto para fechas */
.fecha-dia, .fecha-mes, .fecha-anio {
    display: inline-block;
    transition: var(--transition-standard);
}

.fecha-dia {
    font-weight: bold;
}

.fecha-mes {
    font-style: italic;
}

.carta-fecha:hover .fecha-dia {
    transform: translateY(-2px);
}

.carta-fecha:hover .fecha-mes {
    transform: scale(1.05);
}

.carta-fecha:hover .fecha-anio {
    transform: translateY(2px);
}