*{
  margin: 0;
  padding: 0;
  list-style-type:none;
}
html,body{
  width: 100%;
  height: 100%;
}
.flex-center{
  display: flex;
  justify-content: center;
  align-items: center;
}
.space-between{
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.space-around{
  display: flex;
  justify-content: space-around;
  align-items: center;
}
#app{
  width: 100%;
  min-height: 100%;
  background-color: rgb(37, 36, 36);
  background: url('../images/bg.jpg') center no-repeat;
  background-size: 100% 100%;
}