body{
        margin:0;
    }
        .warper{
            height:50%;
            display: flex;
            flex-direction:column;
            align-content:stretch;
        }
        .header{
            height:5rem;
            background-color: red;
            order: 0;
            flex-shrink: 0;
        }
        .footer{
            height:3rem;
            background-color: blue;
            order: 2;
            flex-shrink: 0;
        }
        .container{
            flex-grow:999;
            order: 1;
            overflow:hidden;
            position: relative;
        }
        .container .baseline{
            min-height:100%;
            height:100%;
            overflow:auto;
        }