textual/docs/examples/styles/overflow.css

Screen {
    background: $background;
    color: black;
}

Vertical {
    width: 1fr;
}

Static {
    margin: 1 2;  
    background: green 80%;  
    border: green wide;
    color: white 90%;
    height: auto;
}    

#right {
    overflow-y: hidden;
}