body{
    max-width:480px;
}

.header{
    display:flex;
    background-color: rgba(255,255,255,.8);
    background-color: white;
    height:40px;
    width:100%;
    max-width:480px;
    align-items: center;
    position: fixed;
    top: 0;
    z-index:10;
    background-color:white;
    box-shadow: 0 1px rgba(0,0,0,.1);
}

main{
    margin-top:45px;
}