textual/docs/examples/styles/height_comparison.tcss

#cells {
    height: 2;       /* (1)! */
}
#percent {
    height: 12.5%;   /* (2)! */
}
#w {
    height: 5w;      /* (3)! */
}
#h {
    height: 12.5h;   /* (4)! */
}
#vw {
    height: 6.25vw;  /* (5)! */
}
#vh {
    height: 12.5vh;  /* (6)! */
}
#auto {
    height: auto;    /* (7)! */
}
#fr1 {
    height: 1fr;     /* (8)! */
}
#fr2 {
    height: 2fr;     /* (9)! */
}

Screen {
    layers: ruler;
    overflow: hidden;
}

Ruler {
    layer: ruler;
    dock: right;
    width: 1;
    background: $accent;
}