.errores {
    background: #258d50;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
    color: #fff;
    display: none;
    font-size: 12px;
    margin-top: -45px;
    margin-left: 180px;
    padding: 10px;
    position: absolute;
    -webkit-border-radius: 10px;
    -moz-box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
    -o-box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
    -webkit-box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
}

.errores:before {
    border-bottom: 8px solid transparent;
    border-left: 8px solid transparent;
    border-right: 8px solid #258d50;
    border-top: 8px solid transparent;
    content: '';
    left: -16px;
    position: absolute;
    top: 8px;
}

.mostrar {
    display: block;
}

.ocultar {
    display: none;
}