/* CSS Básico y funcional */
body {
    font-family: system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    color: #333;
}

/* Encabezado */
header {
    background-color: #1e293b;
    color: white;
    padding: 20px 40px;
    border-bottom: 4px solid #10b981;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-titles h1 { margin: 0; font-size: 24px; }
.header-titles h2 { margin: 5px 0 0 0; font-size: 16px; font-weight: normal; color: #cbd5e1; }

.header-nav-btn {
    display: flex;
    gap: 15px;
}

.nav-btn {
    background-color: #10b981;
    color: white;
    padding: 8px 16px;
    border-radius: 6px;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: background-color 0.2s ease, transform 0.1s ease;
}

.nav-btn:hover {
    background-color: #059669;
    transform: translateY(-1px);
    color: white;
}

/* Contenedor principal */
.container {
    display: flex;
    flex: 1;
}

/* Navegación lateral */
nav {
    width: 250px;
    background-color: #f1f5f9;
    padding: 20px;
    border-right: 1px solid #e2e8f0;
}

nav h3 { margin-top: 0; font-size: 14px; text-transform: uppercase; color: #64748b; }
nav ul { list-style: none; padding: 0; margin: 0; }
nav li { margin-bottom: 10px; }
nav a { text-decoration: none; color: #0f172a; font-weight: 500; }
nav a:hover { color: #10b981; }

nav ul ul {
    padding-left: 15px;
    margin-top: 8px;
    margin-bottom: 5px;
    border-left: 2px solid #cbd5e1;
    margin-left: 10px;
}
nav ul ul li { margin-bottom: 8px; }
nav ul ul a { font-weight: 400; font-size: 14px; color: #475569; }

.menu_select { color: #10b981; font-weight: bold;}

/* Área de contenido */
main {
    flex: 1;
    padding: 40px;
    max-width: 900px;
}

/* Pie de página */
footer {
    background-color: #0f172a;
    color: #94a3b8;
    padding: 15px 40px;
    font-size: 14px;
    border-top: 1px solid #334155;
    display: flex;
    justify-content: space-between;
}

footer p { margin: 0; }
footer strong { color: #e2e8f0; }