.bg-container{
    height: 100%;
    width: 100%;
    filter: blur(20px);
    /* background-color: red!important; */
    z-index: -10!important;
    background-image: url('http://trampklub.pl/sosnowiec/images/gallery/68.jpg');
    background-position: 50% 50%;

}
.bg-overlay{
    height: 100%;
    width: 100%;
    z-index: -9!important;
    background-color: #000;
    opacity: 0.40;
}

/* FLEXBOXY */
body,html{
    height:100%;
}
.header{
    /* height: 25em; */
}
.img-cat{
    overflow: hidden;
    max-height: 10em;
}

footer{
    background-color: black;
}
.card{
     position: relative;
}
.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
}

.card:hover .overlay {
  opacity: 0.85;
}

.text {
  color: white;
  position: absolute;
  top: 50%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
  text-align: center;
}

.categorries .card{
    margin-bottom: 1em;
}