body {
  margin: 0;
  padding: 0;
  background: url(../img/bg.jpg) no-repeat center top;
  background-size: cover;
  font-family: sans-serif;
  height: 100vh;
}

.margin-d{
  padding-top: 10%;
  padding-bottom: 10%
}
.card-btn {
    border-radius: 10px;
}

.card-btn:hover {
    border-radius: 0px;
    box-shadow: 7px 7px 21px 0px rgba(0,0,0,0.75);   
}