/* ═══════════════════════════════════════════════════════════════════
   PRACTICATEST CHILE - CSS COMPLETO Y OPTIMIZADO
   Versión 2.0 - Diciembre 2025
   ═══════════════════════════════════════════════════════════════════ */

/* ═══════════════════════════════════════════════════════════════════
   1. ESTILOS GENERALES
   ═══════════════════════════════════════════════════════════════════ */

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

body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background-color: #f9f9f9;
}

main {
    flex: 1;
    padding: 20px;
    background-color: #f9f9f9;
}

#home, #acerca-de {
    max-width: 1200px;
    margin: 20px auto;
    padding: 20px;
    background-color: #f9f9f9;
}

h1 {
    font-family: Arial, sans-serif;
    font-size: 2.5rem;
    font-weight: bold;
    color: #ffffff;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    text-align: center;
    margin-bottom: 20px;
}

h2 {
    font-family: Arial, sans-serif;
    font-size: 1.8rem;
    font-weight: 600;
    color: #343a40;
    margin-bottom: 15px;
}

h3 {
    font-family: Arial, sans-serif;
    font-size: 1.3rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
}

p {
    font-family: Arial, sans-serif;
    font-size: 1rem;
    line-height: 1.6;
    color: #333;
    margin-bottom: 15px;
}

/* ═══════════════════════════════════════════════════════════════════
   2. HEADER
   ═══════════════════════════════════════════════════════════════════ */

header {
    background-color: #e02131;
    color: white;
    padding: 15px 20px;
    text-align: center;
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: center;
    max-width: 1200px;
    margin: 0 auto;
}

.header-image {
    width: auto;
    height: 60px;
    margin-bottom: 12px;
}

.header-content {
    flex-grow: 1;
    text-align: center;
}

.header-content h1 {
    margin-bottom: 5px;
}

.header-text {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

header nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}

header nav ul li {
    margin: 0 15px;
    position: relative;
}

header nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: bold;
    padding: 5px 10px;
    display: block;
}

header nav ul li a:hover {
    text-decoration: underline;
}

/* Submenú */
nav li ul {
    display: none;
    position: absolute;
    background-color: #e02131;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
}

nav li:hover > ul {
    display: block;
}

nav li ul li {
    float: none;
    display: block;
}

nav li ul li a {
    padding: 12px 16px;
    text-align: left;
}

nav li ul li a:hover {
    background-color: #931721;
}

/* ═══════════════════════════════════════════════════════════════════
   3. FOOTER
   ═══════════════════════════════════════════════════════════════════ */

footer {
    background-color: #07a440;
    color: white;
    padding: 30px 20px;
    margin-top: 50px;
    text-align: center;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-content p {
    margin: 10px 0;
    color: white;
}

.footer-links {
    margin: 15px 0;
}

.footer-links a {
    color: white;
    text-decoration: none;
    margin: 0 10px;
    font-weight: 500;
}

.footer-links a:hover {
    text-decoration: underline;
}

.footer-disclaimer {
    margin-top: 20px;
    font-size: 0.9rem;
    opacity: 0.9;
}

.footer-disclaimer a {
    color: #f8cb3e;
    text-decoration: none;
}

.footer-disclaimer a:hover {
    text-decoration: underline;
}

/* ═══════════════════════════════════════════════════════════════════
   4. PÁGINA PRINCIPAL - HERO SECTION
   ═══════════════════════════════════════════════════════════════════ */

.hero-section {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #e02131, #c01828);
    color: white;
    border-radius: 10px;
    margin-bottom: 40px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.hero-section h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.95;
    color: white;
}

/* ═══════════════════════════════════════════════════════════════════
   5. LICENSE SELECTOR (Tarjetas de Clase B y A)
   ═══════════════════════════════════════════════════════════════════ */

.license-selector {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.license-selector h2 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    font-size: 2rem;
}

.license-card {
    background: white;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.license-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.15);
}

.license-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    border-bottom: 2px solid #f0f0f0;
    padding-bottom: 15px;
}

.license-header h3 {
    font-size: 1.8rem;
    color: #333;
    margin: 0;
}

.license-badge {
    background-color: #07a440;
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: bold;
}

.license-badge.professional {
    background-color: #2196F3;
}

.license-info p {
    font-size: 1.1rem;
    color: #555;
    margin-bottom: 15px;
}

.exam-specs {
    list-style: none;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 10px;
    margin: 20px 0;
}

.exam-specs li {
    background-color: #f8f9fa;
    padding: 10px 15px;
    border-radius: 8px;
    font-size: 0.95rem;
    color: #333;
}

.select-license-btn {
    width: 100%;
    padding: 15px;
    font-size: 1.2rem;
    font-weight: bold;
    background: linear-gradient(135deg, #f8cb3e, #e6b800);
    color: #000;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 20px;
}

.select-license-btn:hover {
    background: linear-gradient(135deg, #e6b800, #d4a600);
    transform: scale(1.02);
}

/* ═══════════════════════════════════════════════════════════════════
   6. MODALES
   ═══════════════════════════════════════════════════════════════════ */

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    justify-content: center;
    align-items: center;
    z-index: 1000;
    overflow-y: auto;
}

.modal-content {
    background: white;
    border-radius: 15px;
    padding: 40px;
    max-width: 900px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: modalFadeIn 0.3s ease;
}

@keyframes modalFadeIn {
    from {
        opacity: 0;
        transform: translateY(-50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.close-modal {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 30px;
    color: #999;
    cursor: pointer;
    transition: color 0.3s ease;
    background: none;
    border: none;
    line-height: 1;
}

.close-modal:hover {
    color: #333;
}

/* ═══════════════════════════════════════════════════════════════════
   7. MODE SELECTOR (Simulacro y Aprendizaje)
   ═══════════════════════════════════════════════════════════════════ */

.mode-selector {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 20px;
}

.mode-card {
    background: #f8f9fa;
    border-radius: 12px;
    padding: 25px;
    text-align: center;
    border: 2px solid #e0e0e0;
    transition: all 0.3s ease;
}

.mode-card:hover {
    border-color: #f8cb3e;
    box-shadow: 0 4px 15px rgba(248, 203, 62, 0.3);
}

.mode-card h3 {
    color: #333;
    margin-bottom: 10px;
    font-size: 1.3rem;
}

.mode-card p {
    color: #666;
    margin-bottom: 15px;
    font-style: italic;
}

.mode-card ul {
    list-style: none;
    padding: 0;
    text-align: left;
    margin: 15px 0;
}

.mode-card ul li {
    padding: 8px 0;
    color: #555;
    font-size: 0.95rem;
    border-bottom: 1px solid #e0e0e0;
}

.mode-card ul li:last-child {
    border-bottom: none;
}

.mode-btn {
    width: 100%;
    padding: 12px;
    font-size: 1.1rem;
    font-weight: bold;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 15px;
}

.mode-btn.simulacro {
    background: linear-gradient(135deg, #e02131, #c01828);
    color: white;
}

.mode-btn.simulacro:hover {
    background: linear-gradient(135deg, #c01828, #a01520);
    transform: scale(1.02);
}

.mode-btn.aprendizaje {
    background: linear-gradient(135deg, #07a440, #069538);
    color: white;
}

.mode-btn.aprendizaje:hover {
    background: linear-gradient(135deg, #069538, #058330);
    transform: scale(1.02);
}

/* Type Selector para Clase A */
.type-selector {
    margin: 20px 0;
    text-align: center;
}

.tipo-select {
    width: 100%;
    max-width: 500px;
    padding: 15px;
    font-size: 1.1rem;
    border: 2px solid #ddd;
    border-radius: 8px;
    background-color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tipo-select:focus {
    outline: none;
    border-color: #2196F3;
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.2);
}

/* ═══════════════════════════════════════════════════════════════════
   8. PANTALLA DE BIENVENIDA DEL EXAMEN
   ═══════════════════════════════════════════════════════════════════ */

.welcome-container {
    max-width: 800px;
    margin: 40px auto;
    padding: 30px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.welcome-container h2 {
    text-align: center;
    color: #e02131;
    margin-bottom: 20px;
    font-size: 2rem;
}

.tipo-descripcion {
    text-align: center;
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 30px;
    font-style: italic;
}

.exam-info {
    margin: 30px 0;
}

.exam-info h3 {
    color: #333;
    margin-bottom: 15px;
    font-size: 1.4rem;
}

.exam-info ul {
    list-style: none;
    padding: 0;
    margin: 20px 0;
}

.exam-info ul li {
    padding: 12px 15px;
    margin: 10px 0;
    background: #f8f9fa;
    border-left: 4px solid #07a440;
    border-radius: 5px;
    font-size: 1.05rem;
}

.warning-box {
    background: #fff3cd;
    border: 2px solid #ffc107;
    border-radius: 10px;
    padding: 20px;
    margin: 20px 0;
}

.warning-box strong {
    color: #856404;
}

.info-box {
    background: #d1ecf1;
    border: 2px solid #0c5460;
    border-radius: 10px;
    padding: 20px;
    margin: 20px 0;
}

.info-box strong {
    color: #0c5460;
}

/* ═══════════════════════════════════════════════════════════════════
   9. BOTONES PRINCIPALES
   ═══════════════════════════════════════════════════════════════════ */

.big-button {
    width: 100%;
    padding: 18px;
    font-size: 1.4rem;
    font-weight: bold;
    background: linear-gradient(135deg, #07a440, #069538);
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 20px 0;
    box-shadow: 0 4px 15px rgba(7, 164, 64, 0.3);
    touch-action: manipulation;
    -webkit-tap-highlight-color: rgba(0,0,0,0.1);
}

.big-button:hover {
    background: linear-gradient(135deg, #069538, #058330);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(7, 164, 64, 0.4);
}

.big-button:active {
    transform: translateY(0);
}

.back-button {
    width: 100%;
    padding: 12px;
    font-size: 1.1rem;
    background: #6c757d;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 10px;
}

.back-button:hover {
    background: #5a6268;
}

.action-button {
    background-color: #f8cb3e;
    color: black;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
}

.action-button:hover {
    background-color: #e6b800;
}

/* ═══════════════════════════════════════════════════════════════════
   10. CONTENEDOR DEL EXAMEN
   ═══════════════════════════════════════════════════════════════════ */

#quiz-container {
    display: none;
    margin-top: 20px;
}

/* Question Index (Índice de preguntas) */
#index-container {
    position: sticky;
    top: 0;
    background: white;
    padding: 15px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 100;
}

.question-index {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
}

.index-button {
    width: 45px;
    height: 45px;
    border: 2px solid #ddd;
    background: white;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.index-button:hover {
    border-color: #2196F3;
    transform: scale(1.1);
}

.index-button.active {
    background: #2196F3;
    color: white;
    border-color: #2196F3;
}

.index-button.answered {
    background: #e8f5e9;
    border-color: #4caf50;
}

.index-button.active.answered {
    background: #4caf50;
    color: white;
}

/* Progress Bar */
.progress-bar-container {
    width: 100%;
    height: 8px;
    background-color: #e0e0e0;
    border-radius: 10px;
    overflow: hidden;
    margin: 20px 0;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #07a440, #06d858);
    transition: width 0.3s ease;
    width: 0%;
}

/* Timer */
.timer {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: white;
    padding: 15px 25px;
    border-radius: 10px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    z-index: 1000;
    min-width: 120px;
    text-align: center;
}

#timer-display {
    font-size: 1.8rem;
    font-weight: bold;
    color: #333;
}

.timer.warning {
    background: #fff3cd;
    border: 2px solid #ffc107;
}

.timer.warning #timer-display {
    color: #856404;
}

.timer.danger {
    background: #f8d7da;
    border: 2px solid #dc3545;
    animation: pulse 1s infinite;
}

.timer.danger #timer-display {
    color: #721c24;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

/* ═══════════════════════════════════════════════════════════════════
   11. PREGUNTAS
   ═══════════════════════════════════════════════════════════════════ */

.question {
    background: white;
    padding: 30px;
    border-radius: 15px;
    margin: 20px 0;
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
}

.question h3 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.question-text {
    font-size: 1.15rem;
    line-height: 1.6;
    color: #333;
    margin: 20px 0;
}

.question.unanswered {
    background-color: #fff3cd;
    border: 2px solid #ffc107;
}

.instruction {
    font-weight: bold;
    color: #333;
    margin-bottom: 10px;
}

.double-score {
    background: linear-gradient(135deg, #ff9800, #f57c00);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.85rem;
    margin-left: 10px;
    display: inline-block;
}

/* Imágenes en preguntas */
.img-container {
    margin: 20px 0;
    text-align: center;
}

.img-container img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* ═══════════════════════════════════════════════════════════════════
   12. OPCIONES DE RESPUESTA
   ═══════════════════════════════════════════════════════════════════ */

.options {
    margin: 25px 0;
}

.option-container {
    padding: 15px;
    margin: 10px 0;
    border-radius: 8px;
    border: 2px solid #e0e0e0;
    transition: all 0.3s ease;
    cursor: pointer;
    display: flex;
    align-items: center;
}

.option-container:hover {
    background: #f5f5f5;
    border-color: #2196F3;
}

.option-container input[type="radio"],
.option-container input[type="checkbox"] {
    margin-right: 15px;
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.option-container label {
    cursor: pointer;
    display: flex;
    align-items: center;
    font-size: 1.05rem;
    width: 100%;
}

.option-letter {
    font-weight: bold;
    color: #2196F3;
    margin-right: 10px;
    min-width: 25px;
}

/* Estilos para opciones correctas/incorrectas */
.option-container.correct {
    background: #e8f5e9;
    border-color: #4caf50;
}

.option-container.incorrect {
    background: #ffebee;
    border-color: #f44336;
}

/* Estilos personalizados para radio y checkbox */
.options input[type="radio"] {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    width: 20px;
    height: 20px;
    border: 2px solid #ccc;
    border-radius: 50%;
    cursor: pointer;
    position: relative;
}

.options input[type="radio"]:checked {
    border-color: #2196F3;
    background-color: #2196F3;
}

.options input[type="radio"]:checked::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: white;
}

.options input[type="checkbox"] {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    width: 20px;
    height: 20px;
    border: 2px solid #333;
    border-radius: 4px;
    cursor: pointer;
    position: relative;
}

.options input[type="checkbox"]:checked {
    background-color: #2196F3;
    border-color: #2196F3;
}

.options input[type="checkbox"]:checked::after {
    content: "✓";
    color: white;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    font-size: 14px;
    font-weight: bold;
}

/* ═══════════════════════════════════════════════════════════════════
   13. EXPLICACIONES
   ═══════════════════════════════════════════════════════════════════ */

.explanation {
    margin-top: 25px;
    padding: 20px;
    border-radius: 10px;
    background: #f0f7ff;
    border-left: 5px solid #2196F3;
}

.explanation h4 {
    margin-top: 0;
    color: #1976D2;
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.explanation p {
    margin: 0;
}

.explanation.correct-explanation {
    background: #e8f5e9;
    border-left-color: #4caf50;
}

.explanation.correct-explanation h4 {
    color: #2e7d32;
}

.explanation.incorrect-explanation {
    background: #ffebee;
    border-left-color: #f44336;
}

.explanation.incorrect-explanation h4 {
    color: #c62828;
}

/* ═══════════════════════════════════════════════════════════════════
   14. BOTONES DE NAVEGACIÓN
   ═══════════════════════════════════════════════════════════════════ */

.navigation-buttons {
    display: flex;
    justify-content: space-between;
    gap: 15px;
    margin: 30px 0;
    flex-wrap: wrap;
}

.nav-btn {
    flex: 1;
    min-width: 150px;
    padding: 12px 25px;
    font-size: 1.1rem;
    font-weight: bold;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: linear-gradient(135deg, #2196F3, #1976D2);
    color: white;
}

.nav-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(33, 150, 243, 0.4);
}

.nav-btn.finish-btn {
    background: linear-gradient(135deg, #e02131, #c01828);
}

.nav-btn.finish-btn:hover {
    box-shadow: 0 4px 15px rgba(224, 33, 49, 0.4);
}

/* ═══════════════════════════════════════════════════════════════════
   15. PANTALLA DE RESULTADOS
   ═══════════════════════════════════════════════════════════════════ */

.results-container {
    background: white;
    border-radius: 15px;
    padding: 30px;
    max-width: 800px;
    margin: 20px auto;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.result-header {
    text-align: center;
    margin-bottom: 30px;
}

.result-status {
    font-size: 3rem;
    margin-bottom: 10px;
}

.result-status.aprobado {
    color: #07a440;
}

.result-status.reprobado {
    color: #e02131;
}

.result-score {
    font-size: 2rem;
    font-weight: bold;
    color: #333;
    margin: 10px 0;
}

.result-percentage {
    font-size: 1.5rem;
    color: #666;
}

.result-message {
    text-align: center;
    margin: 20px 0;
    font-size: 1.1rem;
    color: #555;
}

.result-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 15px;
    margin: 30px 0;
}

.detail-card {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    text-align: center;
}

.detail-card.correct {
    border-left: 4px solid #4caf50;
}

.detail-card.incorrect {
    border-left: 4px solid #f44336;
}

.detail-card.unanswered {
    border-left: 4px solid #ffc107;
}

.detail-card.time {
    border-left: 4px solid #2196F3;
}

.detail-card .label {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 5px;
}

.detail-card .value {
    font-size: 1.5rem;
    font-weight: bold;
    color: #333;
}

.result-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 30px;
    flex-wrap: wrap;
}

.result-btn {
    padding: 12px 30px;
    font-size: 1.1rem;
    font-weight: bold;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.result-btn.primary {
    background: linear-gradient(135deg, #2196F3, #1976D2);
    color: white;
}

.result-btn.secondary {
    background: linear-gradient(135deg, #f8cb3e, #e6b800);
    color: #000;
}

.result-btn.success {
    background: linear-gradient(135deg, #07a440, #069538);
    color: white;
}

.result-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

/* ═══════════════════════════════════════════════════════════════════
   16. MATERIAL DE ESTUDIO
   ═══════════════════════════════════════════════════════════════════ */

#study-material-promo {
    max-width: 1100px;
    margin: 20px auto;
    padding: 20px;
    background-color: #f9f9f9;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

#study-material-promo h2 {
    color: #ff4d4d;
    font-size: 2rem;
    margin-bottom: 20px;
}

#study-material-promo h3 {
    color: #07a440;
    font-size: 1.5rem;
    margin-top: 20px;
}

#study-material-promo p {
    font-size: 1.1rem;
    line-height: 1.6;
    color: #333;
}

#study-material-promo ul {
    list-style-type: disc;
    margin-left: 20px;
    margin-bottom: 20px;
}

#study-material-promo ul li {
    margin-bottom: 10px;
    font-size: 1rem;
    color: #555;
}

.cta-button {
    display: inline-block;
    background-color: #ffcc00;
    color: #000;
    padding: 15px 30px;
    font-size: 1.2rem;
    font-weight: bold;
    text-decoration: none;
    border-radius: 5px;
    margin-top: 20px;
    transition: background-color 0.3s ease;
}

.cta-button:hover {
    background-color: #e6b800;
}

.highlight {
    color: #07a440;
    font-weight: bold;
}

/* ═══════════════════════════════════════════════════════════════════
   17. RESPONSIVE DESIGN
   ═══════════════════════════════════════════════════════════════════ */

@media (max-width: 768px) {
    /* Header */
    .header-container {
        flex-direction: column;
        text-align: center;
    }

    header nav ul {
        flex-direction: column;
        align-items: center;
    }

    header nav ul li {
        margin: 5px 0;
    }

    /* Hero */
    .hero-section h1 {
        font-size: 1.8rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    /* License cards */
    .license-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .exam-specs {
        grid-template-columns: 1fr;
    }

    /* Mode selector */
    .mode-selector {
        grid-template-columns: 1fr;
    }

    /* Modal */
    .modal-content {
        padding: 20px;
        width: 95%;
    }

    /* Welcome container */
    .welcome-container {
        padding: 20px;
        margin: 20px;
    }

    /* Navigation */
    .navigation-buttons {
        flex-direction: column;
    }

    .nav-btn {
        width: 100%;
    }

    /* Timer */
    .timer {
        bottom: 10px;
        right: 10px;
        padding: 10px 15px;
    }

    #timer-display {
        font-size: 1.4rem;
    }

    /* Questions */
    .question {
        padding: 20px;
    }

    /* Results */
    .result-details {
        grid-template-columns: 1fr;
    }

    .result-actions {
        flex-direction: column;
    }

    .result-btn {
        width: 100%;
    }
}

/* ========================================
   ÍNDICE DE PREGUNTAS - ESTADO DE RESPUESTAS
   ======================================== */

/* Pregunta correcta en modo revisión */
.index-button.correct-answer {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
    border: 2px solid #059669;
    box-shadow: 0 2px 8px rgba(16, 185, 129, 0.3);
}

.index-button.correct-answer:hover {
    background: linear-gradient(135deg, #059669 0%, #047857 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

/* Pregunta incorrecta en modo revisión */
.index-button.incorrect-answer {
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    color: white;
    border: 2px solid #dc2626;
    box-shadow: 0 2px 8px rgba(239, 68, 68, 0.3);
    animation: pulse-red 2s ease-in-out infinite;
}

.index-button.incorrect-answer:hover {
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4);
}

/* Animación para preguntas incorrectas */
@keyframes pulse-red {
    0%, 100% {
        box-shadow: 0 2px 8px rgba(239, 68, 68, 0.3);
    }
    50% {
        box-shadow: 0 4px 16px rgba(239, 68, 68, 0.6);
    }
}

/* Pregunta activa con respuesta incorrecta */
.index-button.incorrect-answer.active {
    background: linear-gradient(135deg, #b91c1c 0%, #991b1b 100%);
    border: 3px solid #7f1d1d;
    box-shadow: 0 4px 16px rgba(239, 68, 68, 0.5);
}

/* Pregunta activa con respuesta correcta */
.index-button.correct-answer.active {
    background: linear-gradient(135deg, #047857 0%, #065f46 100%);
    border: 3px solid #064e3b;
    box-shadow: 0 4px 16px rgba(16, 185, 129, 0.5);
}

/* Sin responder en modo revisión */
.index-button.answered:not(.correct-answer):not(.incorrect-answer) {
    /* Mantiene el estilo normal de "answered" cuando no está en modo review */
}

/* ==========================================
   MODO REVISIÓN - ÍNDICE DE PREGUNTAS
   ========================================== */

/* Preguntas correctas en revisión */
.index-button.review-correct {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%) !important;
    color: white !important;
    border: 2px solid #059669 !important;
    box-shadow: 0 2px 8px rgba(16, 185, 129, 0.4) !important;
}

.index-button.review-correct:hover {
    background: linear-gradient(135deg, #059669 0%, #047857 100%) !important;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.5) !important;
}

/* Preguntas incorrectas en revisión */
.index-button.review-incorrect {
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%) !important;
    color: white !important;
    border: 2px solid #dc2626 !important;
    box-shadow: 0 2px 8px rgba(239, 68, 68, 0.4) !important;
}

.index-button.review-incorrect:hover {
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%) !important;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.5) !important;
}

/* Preguntas no respondidas en revisión */
.index-button.review-unanswered {
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%) !important;
    color: white !important;
    border: 2px solid #d97706 !important;
    box-shadow: 0 2px 8px rgba(245, 158, 11, 0.4) !important;
}

.index-button.review-unanswered:hover {
    background: linear-gradient(135deg, #d97706 0%, #b45309 100%) !important;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.5) !important;
}

/* ==========================================
   EXPLICACIÓN NEUTRAL (NO RESPONDIDA)
   ========================================== */

.explanation.neutral-explanation {
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    border-left: 5px solid #b45309;
    color: white;
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
}

.explanation.neutral-explanation h4 {
    color: white;
    margin: 0 0 10px 0;
}
/* ═══════════════════════════════════════════════════════════════════
   FIN DEL CSS
   ═══════════════════════════════════════════════════════════════════ */