Help me in solving FASH04 problem

help
,
1

My issue

//after writing the correct code it is showing error

My code

// your code goes here
header{
    height: 60px;
    background-color:#806BDC;
    text-align: center;
}
.NavBar{
    padding: 18px;
}
#navbar-title{
    color:white;
    font-size: 25px;
}

Learning course: Projects using HTML / CSS
Problem Link: CodeChef: Practical coding for everyone