/* ==========================================
   RESET Y CONFIGURACIÓN BASE
   ========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --dark: #1f2937;
    --gray: #6b7280;
    --light-gray: #f3f4f6;
    --white: #ffffff;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background-color: var(--light-gray);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ==========================================
   NAVEGACIÓN
   ========================================== */
.navbar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: var(--white);
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    font-size: 2rem;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.btn-usuario {
    background-color: rgba(255, 255, 255, 0.2);
}

/* ==========================================
   SECCIÓN HERO
   ========================================== */
.hero {
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
    padding: 8rem 2rem;
    text-align: center;
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.2);
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* ==========================================
   BOTONES
   ========================================== */
.btn {
    display: inline-block;
    padding: 1rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--white);
    color: var(--primary-color);
    box-shadow: var(--shadow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-secondary:hover {
    background-color: var(--white);
    color: var(--primary-color);
}

.btn-submit {
    width: 100%;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 1rem;
    font-size: 1.1rem;
    margin-top: 1rem;
}

.btn-submit:hover {
    opacity: 0.9;
}

/* ==========================================
   SECCIONES
   ========================================== */
.section-registro,
.section-encuestas,
.section-info {
    padding: 4rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.section-header p {
    font-size: 1.2rem;
    color: var(--gray);
}

/* ==========================================
   FORMULARIOS
   ========================================== */
.form-wrapper {
    max-width: 800px;
    margin: 0 auto;
    background: var(--white);
    padding: 3rem;
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--dark);
    font-weight: 600;
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="tel"],
.form-group input[type="password"],
.form-group input[type="number"],
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-hint {
    display: block;
    margin-top: 0.3rem;
    font-size: 0.85rem;
    color: var(--gray);
}

.error-msg {
    display: block;
    color: var(--danger-color);
    font-size: 0.85rem;
    margin-top: 0.3rem;
    min-height: 1.2rem;
}

.form-group input[type="checkbox"] {
    margin-right: 0.5rem;
}

/* ==========================================
   ENCUESTAS
   ========================================== */
.encuestas-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.encuesta-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    cursor: pointer;
}

.encuesta-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.encuesta-icon {
    font-size: 3rem;
    text-align: center;
    margin-bottom: 1rem;
}

.encuesta-card h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.encuesta-card p {
    color: var(--gray);
    margin-bottom: 1rem;
}

.encuesta-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
    color: var(--gray);
}

/* ==========================================
   MODALES
   ========================================== */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.6);
    animation: fadeIn 0.3s;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background-color: var(--white);
    margin: 5% auto;
    padding: 2.5rem;
    border-radius: 15px;
    max-width: 500px;
    box-shadow: var(--shadow-lg);
    animation: slideDown 0.3s;
}

.modal-large {
    max-width: 700px;
}

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

.modal-close {
    color: var(--gray);
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s;
}

.modal-close:hover {
    color: var(--dark);
}

.modal-content h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
}

.form-footer {
    text-align: center;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid #e5e7eb;
}

.form-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

/* ==========================================
   PREGUNTAS DE ENCUESTA
   ========================================== */
.pregunta-grupo {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--light-gray);
    border-radius: 8px;
}

.pregunta-grupo label {
    display: block;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--dark);
}

.opciones-grupo {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.opciones-grupo label {
    font-weight: normal;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* ==========================================
   INFORMACIÓN
   ========================================== */
.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.info-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow);
}

.info-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.info-card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.info-card p {
    color: var(--gray);
}

.security-features {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.security-features h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
}

.features-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.features-list li {
    padding: 0.5rem;
    color: var(--dark);
    font-weight: 500;
}

/* ==========================================
   PIE DE PÁGINA
   ========================================== */
.footer {
    background: var(--dark);
    color: var(--white);
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--white);
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* ==========================================
   MENSAJES DE ÉXITO
   ========================================== */
.mensaje-exito {
    background: var(--secondary-color);
    color: var(--white);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    text-align: center;
}

.mensaje-exito h3 {
    margin-bottom: 0.5rem;
}

/* ==========================================
   DISEÑO RESPONSIVO
   ========================================== */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.5rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .form-wrapper {
        padding: 2rem 1.5rem;
    }
    
    .modal-content {
        margin: 10% 5%;
        width: 90%;
        padding: 1.5rem;
    }
    
    .encuestas-grid {
        grid-template-columns: 1fr;
    }
    
    .info-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .hero {
        padding: 4rem 1rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
}