#mulch {
    background: #333;
    color: #fff;
    text-align: center;
    padding: 20px;
    
}

#mulch .contenedor{
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

 
.cajas {
    margin: 20px;
}

.cajas img {
    width: 190px;
    height: 190px;
    border-radius: 50%;
    border: 5px solid #fff;
    
}