/*
 * Estilos base para el sitio web de BCN Formació.
 *
 * Este fichero define la tipografía, el sistema de rejilla, el diseño del encabezado y del pie
 * de página, las tarjetas (cards), botones, animaciones y comportamiento responsive.
 * Las variables de color se definen en los ficheros de temas (theme‑light.css, theme‑dark.css, theme‑blue.css).
 */

/* Reset y ajustes globales */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--accent-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Contenedores */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* Encabezado */
header {
    background-color: var(--nav-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
}

.logo img {
    height: 40px;
}

/* Menú de navegación */
nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

nav a {
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
}

nav a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -4px;
    width: 0%;
    height: 2px;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

nav a:hover::after,
nav a:focus::after {
    width: 100%;
}

/* Botón de menú hamburguesa (móvil) */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    transition: all 0.3s ease;
}

/* Navegación móvil */
@media (max-width: 768px) {
    nav ul {
        position: absolute;
        top: 100%;
        right: 0;
        background-color: var(--nav-bg);
        flex-direction: column;
        align-items: flex-start;
        width: 200px;
        padding: 1rem;
        border: 1px solid var(--border-color);
        border-radius: 4px;
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-10px);
        transition: opacity 0.3s ease, transform 0.3s ease;
    }
    nav ul.open {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }
    .hamburger {
        display: flex;
    }
}

/* Hero */
.hero {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--hero-text-color, var(--text-color));
    text-align: center;
    min-height: 60vh;
    overflow: hidden;
}

.hero img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: -1;
    opacity: 0.8;
}

.hero .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--hero-overlay, rgba(0,0,0,0.4));
    z-index: -1;
}

.hero-content {
    max-width: 700px;
    padding: 2rem;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.btn-group {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    font-weight: 600;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #fff;
}

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

.btn-primary:hover,
.btn-primary:focus {
    background-color: var(--accent-color-hover, darken(var(--accent-color), 10%));
}

.btn-secondary:hover,
.btn-secondary:focus {
    background-color: var(--accent-color);
    color: #fff;
}

/* Secciones generales */
section {
    padding: 4rem 0;
}

section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

/* Tarjetas (cards) */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.card img {
    width: 100%;
    height: 150px;
    object-fit: cover;
}

.card-content {
    padding: 1rem;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.card-content h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.card-content p {
    flex: 1;
    margin-bottom: 1rem;
}

.card-content .card-link {
    align-self: flex-start;
    color: var(--accent-color);
    font-weight: 600;
}

/* Metodología */
.methodology-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.step {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.step-number {
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
    color: var(--accent-color);
}

.step-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.step-desc {
    font-size: 0.95rem;
}

/* Testimonios */
.testimonials {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.testimonial {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    position: relative;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

.testimonial p {
    font-style: italic;
    margin-bottom: 1rem;
}

.testimonial .author {
    font-weight: 600;
    color: var(--accent-color);
}

/* CTA */
.cta-section {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 3rem;
    text-align: center;
    margin-top: 2rem;
}

.cta-section h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
}

.cta-section p {
    margin-bottom: 1.5rem;
}

/* Pie de página */
footer {
    background-color: var(--nav-bg);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    margin-top: 4rem;
}

footer .footer-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

footer p {
    font-size: 0.9rem;
    text-align: center;
}

/* Animaciones al hacer scroll */
.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Página Cursos: filtros */
.filters {
    text-align: center;
    margin-bottom: 2rem;
}

.filter-btn {
    display: inline-block;
    margin: 0.25rem;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    background-color: var(--card-bg);
    color: var(--text-color);
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.filter-btn.active,
.filter-btn:hover {
    background-color: var(--accent-color);
    color: #fff;
}

/* Contacto */
.contact-form {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-form label {
    font-weight: 600;
}

.contact-form input,
.contact-form textarea {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: var(--card-bg);
    color: var(--text-color);
    resize: vertical;
    font-family: inherit;
}

.contact-form button {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 4px;
    background-color: var(--accent-color);
    color: #fff;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.contact-form button:hover,
.contact-form button:focus {
    background-color: var(--accent-color-hover, darken(var(--accent-color), 10%));
}

/* Estados de error */
.error {
    color: #e74c3c;
    font-size: 0.9rem;
}

/* Utilidades */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}