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

body {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    font-family: Arial, Helvetica, sans-serif;
    background-color: #0f172a;
    color: white;
}

header {
    background: linear-gradient(
        120deg,
        #0f172a,
        #1e3a8a,
        #2563eb
    );
    padding: 15px 30px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.main-nav {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
    list-style: none;
}

.main-nav-item {
    display: inline-block;
}

.main-nav-item a {
    display: block;
    color: white;
    padding: 12px 20px;
    border-radius: 8px;
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
}

/* AL PASAR EL CURSOR */
.main-nav-item a:hover {
    background-color: #3b82f6;
    color: white;
    transform: translateY(-3px);
}

/* AL PRESIONAR */
.main-nav-item a:active {
    background-color: #dc2626;
    color: white;
    transform: scale(0.95);
}

/* OPCIÓN SELECCIONADA */
.main-nav-item a.activo,
.main-nav-item a.activo:hover {
    background-color: #dc2626;
    color: white;
}

/* ACCESIBILIDAD */
.main-nav-item a:focus-visible {
    outline: 2px solid white;
    outline-offset: 3px;
}

/* CONTENIDO */
main {
    flex: 1;
    padding: 60px 20px;
    text-align: center;
}

.bienvenida h1 {
    font-size: 36px;
    margin-bottom: 15px;
    color: #60a5fa;
}

.bienvenida p {
    font-size: 18px;
    color: #cbd5e1;
}

/* PIE DE PÁGINA */
footer {
    background-color: #020617;
    padding: 20px;
    text-align: center;
    color: #94a3b8;
}

/* RESPONSIVO */
@media (max-width: 600px) {
    header {
        padding: 12px;
    }

    .main-nav {
        gap: 5px;
    }

    .main-nav-item a {
        padding: 10px 12px;
        font-size: 14px;
    }

    .bienvenida h1 {
        font-size: 26px;
    }
}