.black-bg{
    /*background-image: url("../img/123.jpg");*/
    background-color: black;
}

.size-img{
    height: 180px;
}

.margin-r{
    margin-right: 2px;
}

.white-bg{
    background-color: white;
}

.margin{
    margin-top: 5rem;
}

.margin-small{
    margin-top: 2rem;
}

.margin-form{
    margin-left: 13rem;
    margin-right: 13rem;
    margin-top: 2rem;
}

@media only screen and (max-width: 1000px){
    .margin-form {
        margin-left: 1rem;
        margin-right: 1rem;
        margin-top: 2rem;
    }

    .size-img {
        height: 80px;
    }

    .text-center {
        text-align: center;
    }

    .margin-small-image {
        margin-bottom: 2rem;
    }
}


.margin-footer{
    padding-top: 2rem;
    padding-bottom: 2rem;
}

.flex{
    display: flex;
}

/*Flip cards de inicio*/
.card {
    border: none;
    background-color: black;
}
.card-flip > div {
    backface-visibility: hidden;
    transition: transform 300ms;
    transition-timing-function: linear;
    width: 100%;
    height: 100%;
    margin: 0;
    background-color:black;
  }

  
  .card-front {
    transform: rotateY(0deg);
  }
  
  .card-back {
    transform: rotateY(180deg);
    position: absolute;
    top: 0;
    color:white;
    margin-left: 5em;
    margin-top: 1em;
  }
  
  .card-flip:hover .card-front {
    transform: rotateY(-180deg);
  }
    
  .card-flip:hover .card-back {
    transform: rotateY(0deg);
    color: white;
  }