.meu-login{
    background: url('https://portalgruposgalvao.com.br/imagens/fundo_login.jpg')
    no-repeat center center fixed !important; 
    -webkit-background-size: cover  !important;
    -moz-background-size: cover  !important;
    -o-background-size: cover  !important;
    background-size: cover  !important;
}