/* Variables de Color y Reset */
:root {
    --primary-color: #0f172a;
    --accent-color: #2563eb;
    --accent-hover: #1d4ed8;
    --text-color: #334155;
    --light-bg: #f8fafc;
    --white: #ffffff;
}

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

html {
    scroll-behavior: smooth;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    color: var(--text-color);
    background-color: var(--white);
    line-height: 1.6;
}

/* Layout Centrado */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 0;
}

/* Botones */
.btn {
    display: inline-block;
    background-color: var(--accent-color);
    color: var(--white);
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s ease;
}

.btn:hover {
    background-color: var(--accent-hover);
}

.btn-block {
    width: 100%;
}

/* Títulos de Sección */
.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 40px;
    color: var(--primary-color);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: var(--accent-color);
    margin: 10px auto 0 auto;
    border-radius: 2px;
}

/* --- 1. Header & Nav --- */
.header {
    background-color: var(--primary-color);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.header-container {
    padding: 15px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    color: var(--white);
    font-size: 1.5rem;
    font-weight: bold;
}

.logo span {
    color: var(--accent-color);
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 20px;
}

.nav-list a {
    color: #cbd5e1;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-list a:hover {
    color: var(--white);
}

/* --- 2. Hero Section --- */
.hero {
    background-color: var(--light-bg);
    margin-top: 60px; /* Evita que el header fijo tape el contenido */
}

.hero-container {
    display: flex;
    flex-direction: column; /* Vista Móvil Primero */
    gap: 40px;
    align-items: center;
}

.hero-content h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.1rem;
    margin-bottom: 30px;
}

.hero-image img {
    width: 100%;
    max-width: 500px;
    border-radius: 12px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

/* --- 3. Ponentes (Cards) --- */
.ponentes {
    background-color: var(--white);
}

.grid-ponentes {
    display: grid;
    grid-template-columns: 1fr; /* 1 columna en móvil */
    gap: 30px;
}

.card {
    background: var(--light-bg);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.3s;
    text-align: center;
}

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

.card img {
    width: 100%;
    height: 250px;
    object-fit: cover;
}

.card-info {
    padding: 20px;
}

.card-info h3 {
    color: var(--primary-color);
    margin-bottom: 5px;
}

.card-info .especialidad {
    color: var(--accent-color);
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 15px;
}

.social-icons a {
    color: var(--text-color);
    font-size: 1.2rem;
    margin: 0 10px;
    transition: color 0.3s;
}

.social-icons a:hover {
    color: var(--accent-color);
}

/* --- 4. Formulario --- */
.inscripcion {
    background-color: var(--light-bg);
}

.container-form {
    max-width: 600px;
    padding: 40px 20px;
    background: var(--white);
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.form-subtitle {
    text-align: center;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
}

.form-group input, .form-group select {
    width: 100%;
    padding: 12px;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    font-size: 1rem;
    outline: none;
}

.form-group input:focus, .form-group select:focus {
    border-color: var(--accent-color);
}

/* --- 5. Footer --- */
.footer {
    background-color: var(--primary-color);
    color: #94a3b8;
    text-align: center;
}

.footer-container {
    padding: 30px 0;
    display: flex;
    flex-direction: column;
    gap: 15px;
    align-items: center;
}

.footer-socials a {
    color: #94a3b8;
    font-size: 1.5rem;
    margin: 0 10px;
    transition: color 0.3s;
}

.footer-socials a:hover {
    color: var(--white);
}

/* --- MEDIA QUERIES (Responsividad para Tablet y Escritorio) --- */

/* Tablets (768px a más) */
@media (min-width: 768px) {
    .grid-ponentes {
        grid-template-columns: repeat(2, 1fr); /* 2 columnas */
    }
    .hero-container {
        flex-direction: row;
        justify-content: space-between;
    }
    .hero-content, .hero-image {
        flex: 1;
    }
}

/* Escritorio (1024px a más) */
@media (min-width: 1024px) {
    .grid-ponentes {
        grid-template-columns: repeat(3, 1fr); /* 3 columnas solicitadas */
    }
    .footer-container {
        flex-direction: row;
        justify-content: space-between;
    }
    .hero-content h1 {
        font-size: 3.5rem;
    }
}