testbed/Textualize__textual/docs/examples/tutorial/stopwatch04.css

Stopwatch {
    layout: horizontal;
    background: $boost;
    height: 5;
    min-width: 50;
    margin: 1;
    padding: 1;
}

TimeDisplay {
    content-align: center middle;
    text-opacity: 60%;
    height: 3;
}

Button {
    width: 16;
}

#start {
    dock: left;
}

#stop {
    dock: left;
    display: none;
}

#reset {
    dock: right;
}

.started {
    text-style: bold;
    background: $success;
    color: $text;
}

.started TimeDisplay {
    text-opacity: 100%;
}

.started #start {
    display: none
}

.started #stop {
    display: block
}

.started #reset {
    visibility: hidden
}