*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;

    }

body{
    width: 100%;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;

}   
.cont{
    width:100%;
    height: 100%;
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}
.cont>div{
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;

}

.b1{
    z-index: -1;
    justify-content: flex-end;
    align-items: flex-start;
}
.b2{
    z-index: -2;
    justify-content: center;
    align-items: flex-start;
}
.b3{
    z-index: -3;
    justify-content: flex-end;
    align-items: flex-end;
}
.b4{
    z-index: -4;
}
  .b5{
    z-index: -5;
  } 
  
  
.a1, .a2, .a3, .a4{
    width:100% ;
    height: 100%;

}

.a5{
    width:100% ;
    height: 100%;
    
}