*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:Arial,Helvetica,sans-serif;
}

body{
    background:#f1f5f9;
}

.contenedor{
    display:flex;
    min-height:100vh;
}

.menu{
    width:260px;
    background:#0f172a;
    color:#fff;
    padding:20px;
}

.menu h2{
    margin-bottom:25px;
}

.menu a{
    display:block;
    color:#fff;
    text-decoration:none;
    padding:12px;
    border-radius:8px;
    margin-bottom:8px;
}

.menu a:hover{
    background:#2563eb;
}

.contenido{
    flex:1;
    padding:30px;
}

.cards{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(250px,1fr));
    gap:20px;
    margin-top:25px;
}

.card{
    background:#fff;
    border-radius:12px;
    padding:20px;
    box-shadow:0 5px 15px rgba(0,0,0,.15);
}

.card h3{
    color:#2563eb;
    margin-bottom:10px;
}