/* --- Variables y Reset --- */
:root {
    --primary-blue: #1a2b4a;  /* Azul oscuro profundo */
    --accent-teal: #00cea6;   /* Turquesa vibrante */
    --text-dark: #333333;
    --text-light: #666666;
    --bg-light: #ffffff;
    --bg-gray: #f9fafb;
    --white: #ffffff;
    --max-width: 1200px;
}

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

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

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* --- Navbar --- */
.navbar {
    background-color: var(--bg-gray);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 35px;
    height: 35px;
    fill: var(--primary-blue);
}

.logo-text {
    display: flex;
    flex-direction: column;
    font-weight: 800;
    font-size: 1rem;
    line-height: 1;
    color: var(--primary-blue);
}

.logo-accent {
    color: var(--accent-teal);
    font-size: 0.8rem;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-dark);
    transition: color 0.3s;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--primary-blue);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
}

.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: 6px;
    font-weight: 700;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn-login {
    background-color: var(--primary-blue);
    color: var(--white);
    padding: 8px 20px;
    border-radius: 20px; /* Bordes más redondos como en la imagen */
    font-size: 0.9rem;
}

/* --- Hero Section --- */
.hero {
    position: relative;
    height: 85vh; /* Altura grande */
    display: flex;
    align-items: center;
    color: var(--white);
    /* Imagen de fondo genérica de estudiantes + Overlay */
    background-image: url('https://images.unsplash.com/photo-1523240795612-9a054b0db644?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=80');
    background-size: cover;
    background-position: center;
}

/* Capa azul oscura transparente encima de la foto */
.hero-overlay {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(to right, rgba(26, 43, 74, 0.9), rgba(26, 43, 74, 0.7));
}

.hero-content {
    position: relative; /* Para estar encima del overlay */
    z-index: 2;
    max-width: 600px; /* Limita el ancho del texto */
    margin-left: auto; margin-right: auto; /* Centrado en layout general */
    /* En tu imagen el texto está a la izquierda, así que forzamos la alineación al container */
    width: 100%; 
}

.badge {
    background-color: rgba(0, 206, 166, 0.2); /* Fondo transparente turquesa */
    color: var(--accent-teal);
    padding: 5px 12px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 700;
    border: 1px solid var(--accent-teal);
    display: inline-block;
    margin-bottom: 20px;
    text-transform: uppercase;
}

.hero h1 {
    font-size: 3.5rem;
    line-height: 1.1;
    margin-bottom: 20px;
    font-weight: 700;
}

.hero h1 .highlight {
    color: var(--accent-teal);
    display: block; /* Fuerza salto de línea visual si es necesario o resalta */
}

.hero p {
    font-size: 1.1rem;
    margin-bottom: 35px;
    opacity: 0.9;
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: 15px;
}

.btn-primary {
    background-color: var(--accent-teal);
    color: var(--primary-blue);
}

.btn-primary:hover {
    background-color: #00b392;
}

.btn-outline {
    background-color: transparent;
    border: 2px solid rgba(255,255,255,0.3);
    color: var(--white);
}

.btn-outline:hover {
    border-color: var(--white);
    background-color: rgba(255,255,255,0.1);
}

/* --- Sección Asignaturas --- */
.section-padding {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 2.2rem;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

.section-header p {
    color: var(--text-light);
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

/* Estilo Tarjeta (Variación Landing Page) */
.course-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
    transition: transform 0.3s ease;
}

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

.card-image {
    height: 180px;
    width: 100%;
    background-color: #eee;
}

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

.img-placeholder {
    width: 100%; height: 100%;
    background: linear-gradient(135deg, #cbd5e1 0%, #94a3b8 100%);
}

.card-body {
    padding: 20px;
}

.card-title-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.card-title-row h3 {
    font-size: 0.95rem;
    color: var(--primary-blue);
    font-weight: 700;
    text-transform: uppercase;
}

.check-circle {
    width: 24px; height: 24px;
    background-color: #d1fae5; /* Verde muy muy claro de fondo */
    color: var(--accent-teal);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: bold;
}

.progress-container {
    height: 6px;
    background-color: #f1f5f9;
    border-radius: 3px;
    margin-bottom: 10px;
    overflow: hidden;
}

.progress-bar .fill {
    height: 100%;
    background-color: var(--accent-teal);
    border-radius: 3px;
}

.card-code {
    font-size: 0.75rem;
    color: #999;
    font-weight: 500;
}

/* --- Stats Section --- */
.stats {
    background-color: var(--primary-blue);
    color: var(--white);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    color: var(--accent-teal);
    font-weight: 700;
    margin-bottom: 5px;
}

.stat-item p {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* --- Footer --- */
.footer {
    background-color: var(--white);
    padding: 70px 0 20px 0;
    border-top: 1px solid #eee;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr; /* La primera columna es más ancha */
    gap: 40px;
    margin-bottom: 50px;
}

.footer h4 {
    color: var(--primary-blue);
    margin-bottom: 20px;
    font-size: 1rem;
}

.footer ul li {
    margin-bottom: 12px;
}

.footer a, .contact-list li {
    color: var(--text-light);
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer a:hover {
    color: var(--accent-teal);
}

.footer-desc {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-top: 15px;
    max-width: 300px;
}

.footer-bottom {
    border-top: 1px solid #eee;
    padding-top: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #999;
    font-size: 0.85rem;
}

.social-icons span {
    margin-left: 15px;
    font-size: 1.2rem;
    cursor: pointer;
    opacity: 0.6;
}
.social-icons span:hover { opacity: 1; }

/* Responsive adjustments */
@media (max-width: 768px) {
    .nav-links { display: none; } /* Ocultar menú en móvil para simplificar */
    .hero h1 { font-size: 2.5rem; }
    .stats-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
    .footer-grid { grid-template-columns: 1fr; gap: 30px; }
}