.proposta{
    display: none;
    width: 100%;
    height: 100%;
    position: absolute;
    z-index: 1000px;
    top: 0; left: 0;
    background-color: #eee;
}
.proposta2{
    width: 100%;
    overflow: auto;
}

#alerta{
    width: 100%;
    position: absolute;
    z-index: 1;
    top: 1%; right: 0;
    padding: 0 20%;
}