:root {
    
    --primary: #7B5EFF;   /* Morado principal (Brillante) */
    --secondary: #FF6BD6; /* Rosa Neón/Magenta (Acento y botones de navegación) */
    --accent: #9D4EDD;    /* Morado oscuro (Detalles y sombras) */
    --bg-start: #1A0B3D;
    --bg-mid: #2D1B69;
    
    --card-bg: #FFFFFF;
    --dark: #1F2937;
    --light-text: #F4F7FA;

    /* Colores para los módulos de información */
    --info-bg: #FFFFFF;
    --info-dark-text: #1A237E;
    
    /* Colores funcionales */
    --when-color: #10B981;  /* Verde (Interrupción/Éxito) */
    --while-color: #7B5EFF; /* Cyan/Azul (Simultaneidad/Estructura) */
    --formula-box: #EEF2FF;
}

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

body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(135deg, var(--bg-start) 0%, var(--bg-mid) 50%, #6E5BFF 100%);
    color: #F0F4FF; /* Texto más claro para mejor visibilidad */
    line-height: 1.7;
    min-height: 100vh;
    margin: 0;
    padding: 0;
    overflow-x: hidden;
}

/* Títulos principales */
h1, h2 {
    font-family: 'Cinzel', serif;
    color: var(--light-text);
    text-shadow: 0 2px 8px rgba(0,0,0,0.5); /* Sombra más fuerte para mejor contraste */
    margin: 0 0 0.8rem;
}
h1 { font-size: 2.6rem; }
h2 { font-size: 1.9rem; }

/* HEADER y Navegación Mejorada */
header {
    position: sticky;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 0;
    backdrop-filter: blur(12px);
    background: rgba(26, 11, 61, 0.95); /* Fondo más oscuro para mejor contraste */
    border-bottom: 2px solid rgba(123, 94, 255, 0.3);
}
.navbar { 
    max-width: 1300px; 
    margin: 0 auto; 
    padding: 0 2rem; 
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
}
.logo { 
    font-family: 'Cinzel', serif; 
    font-size: 1.9rem; 
    color: #FFFFFF; 
    font-weight: 700; 
    text-decoration: none;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
}
.nav-links { 
    list-style: none; 
    display: flex; 
    gap: 1.5rem; 
    padding: 0; 
    margin: 0; 
}
.nav-links a { 
    color: #E0E7FF; /* Color más claro para mejor visibilidad */
    text-decoration: none; 
    font-weight: 700; /* Texto más grueso */
    display: flex; 
    align-items: center; 
    gap: 8px;
    padding: 10px 18px;
    border-radius: 20px;
    transition: all 0.3s;
    text-shadow: 0 1px 3px rgba(0,0,0,0.5);
}
.nav-links a:hover { 
    color: #FFFFFF;
    background: rgba(255, 107, 214, 0.25);
    transform: translateY(-2px);
}
.nav-links a.active { 
    color: var(--secondary); 
    background: rgba(255, 107, 214, 0.2);
    box-shadow: 0 0 20px rgba(255, 107, 214, 0.4);
}

/* Menú desplegable */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-content {
    display: none;
    position: absolute;
    background: rgba(26, 11, 61, 0.98);
    backdrop-filter: blur(15px);
    min-width: 280px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.4);
    z-index: 1001;
    border-radius: 15px;
    padding: 10px 0;
    border: 1px solid rgba(123, 94, 255, 0.3);
    top: 100%;
    left: 0;
    animation: fadeIn 0.3s ease;
}

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

.dropdown-content a {
    color: #E0E7FF;
    padding: 12px 20px;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 0.95rem;
    transition: all 0.3s;
}

.dropdown-content a:hover {
    background: rgba(123, 94, 255, 0.3);
    color: #FFFFFF;
    transform: translateX(5px);
}

.dropdown:hover .dropdown-content {
    display: block;
}

/* Flecha en el menú desplegable */
.dropdown > a span:last-child {
    font-size: 1.2rem;
    margin-left: 5px;
    transition: transform 0.3s;
}

.dropdown:hover > a span:last-child {
    transform: rotate(180deg);
}

/* Botón de menú móvil */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.8rem;
    cursor: pointer;
    padding: 5px;
}

/* Menú móvil */
.mobile-menu {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: rgba(26, 11, 61, 0.98);
    backdrop-filter: blur(10px);
    padding: 20px;
    z-index: 999;
    flex-direction: column;
    gap: 10px;
    border-top: 2px solid rgba(123, 94, 255, 0.3);
}

.mobile-menu a {
    color: #E0E7FF;
    text-decoration: none;
    padding: 12px 15px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: all 0.3s;
    font-weight: 600;
}

.mobile-menu a:hover, .mobile-menu a.active {
    background: rgba(123, 94, 255, 0.3);
    color: #FFFFFF;
}

/* ==================================================== */
/* === ESTILOS PARA PÁGINAS DE INFORMACIÓN (Módulos) === */
/* ==================================================== */
.info-container {
    max-width: 1200px;
    margin: 100px auto 50px auto;
    padding: 0 30px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.section-title {
    font-family: 'Cinzel', serif;
    font-size: 3.2rem;
    color: var(--light-text);
    text-align: center;
    margin-bottom: 1.5rem;
    letter-spacing: 1px;
    text-transform: uppercase;
    background: linear-gradient(135deg, var(--light-text) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.page-subtitle {
    text-align: center;
    font-size: 1.3rem;
    color: #E0E7FF;
    opacity: 0.95;
    margin-bottom: 60px;
    max-width: 900px;
    line-height: 1.8;
    margin-left: auto;
    margin-right: auto;
}

/* Módulos de contenido - CENTRADOS Y MEJOR ORGANIZADOS */
.concept-module {
    background: var(--info-bg);
    border-radius: 20px;
    padding: 40px;
    margin-bottom: 50px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
    border-left: 8px solid var(--primary);
    transition: all 0.4s;
    width: 100%;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

.concept-module:hover {
    box-shadow: 0 20px 45px rgba(0, 0, 0, 0.2);
    transform: translateY(-5px);
}

.concept-module h3 {
    font-family: 'Lora', serif;
    font-size: 2rem;
    color: var(--info-dark-text);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 2rem;
    padding-bottom: 15px;
    border-bottom: 3px solid var(--primary);
    text-shadow: none;
}

.concept-module h3 span {
    font-size: 2.4rem;
    color: var(--secondary);
}

.concept-module p {
    font-family: 'Poppins', sans-serif;
    font-size: 1.15rem;
    color: #2D3748; /* Color más oscuro para mejor contraste */
    line-height: 1.8;
    margin-bottom: 1.8rem;
    text-align: justify;
    text-align-last: center;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

/* Estilos para el texto de énfasis */
.past-cont {
    color: var(--primary);
    font-weight: 800;
    font-size: 1.2rem;
}

.past-simple {
    color: var(--secondary);
    font-weight: 800;
    font-size: 1.2rem;
}

.keyword {
    color: var(--accent);
    font-weight: 900;
    font-size: 1.2rem;
}

.formula-code {
    font-family: 'Courier New', monospace;
    font-weight: 700;
    font-size: 1.1rem;
}

/* Cajas de Fórmulas CENTRADAS */
.formula-box {
    background: linear-gradient(135deg, var(--formula-box) 0%, #E0E7FF 100%);
    padding: 30px;
    border-radius: 15px;
    margin: 25px auto;
    font-family: 'Courier New', monospace;
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--accent);
    text-align: center;
    box-shadow: inset 0 0 20px rgba(123, 94, 255, 0.1);
    border: 3px solid var(--primary);
    max-width: 900px;
}

/* Cuadros de contraste CENTRADOS */
.contrast-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin: 30px auto;
    justify-content: center;
    max-width: 1000px;
}

.contrast-box {
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    font-family: 'Lora', serif;
    color: #2D3748;
    text-align: center;
    transition: transform 0.3s;
}

.contrast-box:hover {
    transform: translateY(-5px);
}

.contrast-box h4 {
    font-family: 'Cinzel', serif;
    font-size: 1.4rem;
    margin-top: 0;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid;
    text-shadow: none;
}

.when-box {
    background: linear-gradient(135deg, #E6FFF6 0%, #D4F7E7 100%);
    border: 3px solid var(--when-color);
}

.when-box h4 {
    border-bottom-color: var(--when-color);
    color: var(--when-color);
}

.while-box {
    background: linear-gradient(135deg, #E0F7FA 0%, #CAF0F8 100%);
    border: 3px solid var(--while-color);
}

.while-box h4 {
    border-bottom-color: var(--while-color);
    color: var(--while-color);
}

.structure-box {
    background: linear-gradient(135deg, #F3E5F5 0%, #E9D8FD 100%);
    border: 3px solid var(--secondary);
}

.structure-box h4 {
    border-bottom-color: var(--secondary);
    color: var(--secondary);
}

/* Ejemplos visuales CENTRADOS */
.example-image-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    margin: 30px auto;
    padding: 25px;
    background: linear-gradient(135deg, var(--formula-box) 0%, #F0F4FF 100%);
    border-radius: 15px;
    border: 2px dashed var(--accent);
    max-width: 1000px;
    justify-content: center;
}

.example-box-visual {
    background: white;
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    border: 2px solid #e0e0e0;
    text-align: center;
    transition: transform 0.3s;
}

.example-box-visual:hover {
    transform: translateY(-5px);
}

.example-box-visual p {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--info-dark-text);
    margin: 15px 0 0 0;
    text-align: center;
    line-height: 1.6;
}

/* Placeholders de imágenes */
.image-placeholder {
    width: 100%;
    height: 160px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.image-placeholder span {
    font-size: 3.5rem;
    color: white;
}

/* Galería de imágenes CENTRADA */
.image-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin: 40px auto;
    justify-content: center;
    max-width: 1000px;
}

.gallery-item {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    transition: all 0.4s;
    text-align: center;
}

.gallery-item:hover {
    transform: translateY(-10px) scale(1.03);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.25);
}

.gallery-caption {
    padding: 25px;
    text-align: center;
}

.gallery-caption p {
    margin: 0;
    color: #2D3748;
    font-weight: 700;
    font-size: 1.1rem;
    line-height: 1.7;
}

/* Tabla comparativa CENTRADA */
.comparison-table {
    width: 100%;
    border-collapse: collapse;
    margin: 35px auto;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
    border-radius: 15px;
    overflow: hidden;
    max-width: 1000px;
}

.comparison-table th {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: white;
    padding: 20px;
    text-align: center;
    font-family: 'Poppins', sans-serif;
    font-weight: 700;
    font-size: 1.2rem;
}

.comparison-table td {
    padding: 18px;
    text-align: center;
    border-bottom: 1px solid #E0E0E0;
    color: #2D3748;
    font-size: 1.05rem;
}

.comparison-table tr:nth-child(even) {
    background: #F8F8F8;
}

.comparison-table .when-row {
    border-left: 6px solid var(--while-color);
}

.comparison-table .while-row {
    border-left: 6px solid var(--while-color);
}

/* Línea de tiempo CENTRADA */
.timeline-container {
    margin: 30px auto;
    text-align: center;
    max-width: 900px;
}

.timeline {
    position: relative;
    height: 80px;
    background: #E0E0E0;
    border-radius: 40px;
    margin: 20px auto;
    overflow: hidden;
    max-width: 800px;
}

.timeline-progress {
    position: absolute;
    height: 100%;
    border-radius: 40px;
    width: 0%;
    transition: width 1.5s ease-in-out;
}

.when-progress {
    background: linear-gradient(90deg, var(--while-color), #ed58e3);
}

.while-progress {
    background: linear-gradient(90deg, var(--while-color), #ed58e3);
}

.timeline-labels {
    display: flex;
    justify-content: space-between;
    padding: 0 25px;
    position: relative;
    z-index: 2;
    color: #2D3748;
    font-weight: 700;
    height: 100%;
    align-items: center;
    font-size: 1.1rem;
}

/* Elementos interactivos CENTRADOS */
.interactive-element {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: white;
    padding: 20px;
    border-radius: 15px;
    margin: 30px auto;
    cursor: pointer;
    transition: all 0.4s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    max-width: 900px;
    border: 2px solid  ;
}

.interactive-element:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 15px 35px rgba(123, 94, 255, 0.4);
}

.hidden-content {
    display: none;
    background: var(--formula-box);
    padding: 25px;
    border-radius: 12px;
    margin: 20px auto;
    border-left: 5px solid var(--secondary);
    max-width: 900px;
    text-align: center;
}

/* Consejos de memoria CENTRADOS */
.memory-tip {
    background: #ffc4f6;
    border: 2px dashed #3746ec;
    padding: 20px;
    border-radius: 12px;
    margin: 25px auto;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 15px;
    max-width: 900px;
    color: #3746ec;
}

.memory-tip span {
    color: #ffb300;
    flex-shrink: 0;
    font-size: 2rem;
}

.memory-tip strong {
    color: #2D3748;
    font-size: 1.1rem;
}

/* Módulo de Advertencia (Rojo) */
.warning-module {
    border-left: 8px solid #FF5252;
    background: linear-gradient(135deg, #FFF1F1 0%, #FFE5E5 100%);
    color: #FF5252;
    text-align: center;
}

.warning-module h3 span {
    color: #FF5252;
}

.warning-module h3 {
    border-bottom-color: rgba(255, 82, 82, 0.3);
    color: #B71C1C;
}

.warning-module p {
    color: #2D3748;
}

/* Práctica interactiva CENTRADA */
.practice-box {
    background: white;
    border: 3px solid var(--primary);
    border-radius: 20px;
    padding: 40px;
    margin: 40px auto;
    box-shadow: 0 10px 35px rgba(0, 0, 0, 0.15);
    max-width: 900px;
}

.quiz-item {
    margin: 25px 0;
    padding: 25px;
    border-radius: 15px;
    background: #F8F9FA;
    text-align: center;
}

.quiz-options {
    display: flex;
    gap: 20px;
    margin: 20px 0;
    justify-content: center;
}

.quiz-option {
    flex: 1;
    max-width: 200px;
    padding: 15px 25px;
    border: 3px solid var(--primary);
    background: white;
    color: var(--primary);
    border-radius: 12px;
    cursor: pointer;
    font-weight: 700;
    font-size: 1.1rem;
    transition: all 0.3s;
}

.quiz-option:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-3px);
}

.quiz-feedback {
    padding: 15px;
    margin-top: 15px;
    border-radius: 10px;
    background: #E8F5E9;
    border-left: 5px solid #4CAF50;
    text-align: center;
}

.quiz-feedback.hidden {
    display: none;
}

.incorrect-text {
    text-decoration: line-through;
    color: #FF5252;
    font-weight: 700;
}

.correct {
    background: rgba(16, 185, 129, 0.3) !important;
    border: 3px solid var(--when-color);
}

.incorrect {
    background: rgba(255, 82, 82, 0.3) !important;
    border: 3px solid #FF5252;
}

/* Sección de Recursos Multimedia */
.multimedia-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin: 40px auto;
    justify-content: center;
    max-width: 1000px;
}

.video-container {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    transition: all 0.4s;
}

.video-container:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.25);
}

.video-placeholder {
    cursor: pointer;
    text-align: center;
}

.video-thumbnail {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.video-placeholder:hover .video-thumbnail img {
    transform: scale(1.05);
}

.play-button {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(123, 94, 255, 0.9);
    width: 70px;
    height: 70px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}

.play-button span {
    color: white;
    font-size: 3rem;
}

.video-placeholder:hover .play-button {
    background: var(--secondary);
    transform: translate(-50%, -50%) scale(1.1);
}

.video-info {
    padding: 25px;
    text-align: center;
}

.video-info h4 {
    color: #2D3748;
    margin-bottom: 10px;
    font-size: 1.3rem;
}

.video-info p {
    color: #666;
    margin-bottom: 10px;
    font-size: 0.95rem;
}

.video-description {
    color: #2D3748 !important;
    font-size: 1rem !important;
    line-height: 1.6;
}

/* Modal de video */
.video-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.video-modal-content {
    width: 90%;
    max-width: 900px;
    position: relative;
}

.video-modal iframe {
    width: 100%;
    height: 500px;
    border-radius: 10px;
}

.close-modal {
    position: absolute;
    top: -40px;
    right: 0;
    color: white;
    font-size: 2.5rem;
    cursor: pointer;
    background: rgba(255, 107, 214, 0.9);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Navegación mejorada y CENTRADA */
.navigation-simple {
    display: flex;
    justify-content: space-between;
    margin: 60px auto;
    gap: 20px;
    max-width: 1000px;
    background: rgba(45, 27, 105, 0.95);
    border-radius: 20px;
    padding: 30px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

.nav-prev, .nav-next {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 25px;
    border-radius: 15px;
    text-decoration: none;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    font-size: 1.2rem;
    color: white;
}

.nav-prev {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    text-align: left;
    justify-content: flex-start;
}

.nav-next {
    background: linear-gradient(135deg, var(--secondary) 0%, #E94E83 100%);
    text-align: right;
    justify-content: flex-end;
}

.nav-prev:hover, .nav-next:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.nav-prev small, .nav-next small {
    display: block;
    opacity: 0.9;
    font-size: 0.95rem;
    margin-top: 5px;
}

/* Footer */
footer { 
    text-align: center; 
    padding: 2.5rem; 
    color: #E0E7FF; 
    font-size: 1rem; 
    background: rgba(26, 11, 61, 0.9);
    margin-top: 60px;
}

.footer-links {
    margin-top: 20px;
}

.footer-links a {
    color: #E0E7FF;
    text-decoration: none;
    margin: 0 12px;
    opacity: 0.9;
    transition: opacity 0.3s;
    font-weight: 600;
}

.footer-links a:hover {
    opacity: 1;
    text-decoration: underline;
    color: var(--secondary);
}

/* Botón para subir */
.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: white;
    border: none;
    border-radius: 50%;
    width: 60px;
    height: 60px;
    font-size: 1.8rem;
    cursor: pointer;
    box-shadow: 0 6px 20px rgba(123, 94, 255, 0.5);
    z-index: 100;
    display: none;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.scroll-to-top:hover {
    transform: translateY(-5px) scale(1.1);
    box-shadow: 0 10px 25px rgba(123, 94, 255, 0.7);
}

/* Animaciones */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.concept-module {
    animation: fadeInUp 0.6s ease-out;
    animation-fill-mode: both;
}

.concept-module:nth-child(1) { animation-delay: 0.1s; }
.concept-module:nth-child(2) { animation-delay: 0.2s; }
.concept-module:nth-child(3) { animation-delay: 0.3s; }
.concept-module:nth-child(4) { animation-delay: 0.4s; }
.concept-module:nth-child(5) { animation-delay: 0.5s; }

/* Responsive */
@media (max-width: 1024px) {
    .info-container {
        padding: 0 20px;
    }
    
    .concept-module {
        padding: 30px;
    }
    
    .section-title {
        font-size: 2.8rem;
    }
}

@media (max-width: 900px) {
    .nav-links { 
        display: none; 
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .navbar { 
        justify-content: space-between; 
    }
    
    .contrast-grid { 
        grid-template-columns: 1fr; 
        max-width: 500px;
    }
    
    .navigation-simple {
        flex-direction: column;
        padding: 25px;
    }
    
    .nav-prev, .nav-next {
        padding: 20px;
        font-size: 1.1rem;
    }
    
    .comparison-table {
        font-size: 0.95rem;
    }
    
    .example-image-container {
        grid-template-columns: 1fr;
        max-width: 500px;
    }
    
    .multimedia-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
    }
}

@media (max-width: 600px) {
    .section-title { 
        font-size: 2.2rem; 
        padding: 0 15px;
    }
    
    .page-subtitle {
        font-size: 1.1rem;
        padding: 0 15px;
    }
    
    .concept-module { 
        padding: 25px 20px;
        margin-bottom: 30px;
    }
    
    .concept-module h3 { 
        font-size: 1.7rem;
        flex-direction: column;
        gap: 10px;
    }
    
    .concept-module h3 span {
        font-size: 2.2rem;
    }
    
    .concept-module p {
        font-size: 1.05rem;
        text-align: left;
        text-align-last: left;
    }
    
    .formula-box {
        padding: 20px;
        font-size: 1.1rem;
    }
    
    .quiz-options {
        flex-direction: column;
        align-items: center;
    }
    
    .quiz-option {
        max-width: 100%;
        width: 100%;
    }
    
    .image-gallery {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .video-modal iframe {
        height: 300px;
    }
    
    .mobile-menu {
        top: 80px;
    }
    
    body {
        font-size: 16px;
    }
}
.image-gallery {
    display: flex;
    gap: 15px;       /* Espacio entre los iconos */
    margin: 20px 0;  /* Separación arriba y abajo */
}

/* El cuadrado de color (donde sale el ícono) */
.image-placeholder {
    width: 60px;     /* Ancho fijo */
    height: 60px;    /* Alto fijo */
    
    /* ESTO ES LO QUE CENTRA EL ÍCONO: */
    display: flex;   
    justify-content: center; 
    align-items: center;
    
    border-radius: 12px; /* Bordes redondeados */
    color: white;        /* Color del ícono */
    flex-shrink: 0;      /* Evita que se aplaste si hay poco espacio */
}

/* Control del tamaño del ícono para que no se vea gigante */
.image-placeholder .material-symbols-sharp {
    font-size: 30px !important; /* Tamaño controlado */
    width: auto;
    height: auto;
    line-height: 1;
}

@media (max-width: 400px) {
    .section-title {
        font-size: 1.8rem;
    }
    
    .concept-module h3 {
        font-size: 1.5rem;
    }
    
    .logo {
        font-size: 1.6rem;
    }
    
    .nav-prev span, .nav-next span {
        font-size: 1.5rem;
    }
}