.c1-box {
    display:flex;
    flex-flow:column;
    overflow:visible; /* overwrite c1-dialog */
}
.c1-box.c1-box { /* stronger */
    padding:0;
}
.c1-box > .-body {
    /* flex:1 0 auto; old */
    flex:1 1 auto;
    overflow:auto;
    padding:20px;
}
.c1-box > .-head ,
.c1-box > .-foot {
    flex:0 0 auto;
    display:flex;
    background:#000;
    color:#fff;
    padding:10px 20px;
}
.c1-box > .-head > .-title {
    flex:1;
}
.c1-box > .-foot {
    background:transparent;
}


/* neu */
tr.c1-box-head > * {
    position:sticky;
    top:0;
    left:0;
    background:#000;
    color:#fff;
    padding:10px;
}