gnome-shell/src/st/test-theme.css

stage {
}

#group1 {
    padding: 12pt;
    padding-right: 12px;
    padding-bottom: 2em;
    padding-left: 1in;

    margin: 12pt;
    margin-right: 12px;
    margin-bottom: 2em;
    margin-left: 1in;

    background: #ff0000 url('some-background.png');

    font-feature-settings: "tnum";
}

#text1 {
    background-image: inherit;
}

.special-text {
    font-size: 24pt;
    font-style: italic;
}

StBin.special-text {
    font-weight: bold;
}

#text2 {
    background: inherit;
    background: none; /* also overrides the color */
}

#group2 {
    font: italic 12px serif;
    font-feature-settings: "tnum", "zero";
}

#text3 {
    font-variant: small-caps;
    font-weight: bold;
    font-style: oblique;
    font-size: 200%;
    font-feature-settings: "pnum";
}

#text4 {
    font-feature-settings: normal;
}

StBin {
    padding: 10px;
}

StButton {
    padding-right: 20px;
}

#group1 > #text1 {
    color: #00ff00;
}

stage > #text2 {
    color: #ff0000;
}

#group2 > #text3 {
    font-feature-settings: inherit;
}

#group2 {
    background-image: url('other-background.png');
    padding: 1px 2px 3px 4px;
    margin: 1px 2px 3px 4px;

    border: 2px solid #000000;
    border-bottom: 5px solid #0000ff;
    border-radius: 10px 10px 0px 0px;
}

ClutterText:hover, StLabel:hover {
    text-decoration: underline;
}

ClutterText:visited, StLabel:visited {
    color: #888888;
}

StLabel:boxed {
    border: 1px;
}

#group4 {
    margin: 1px 2px 3px;
}

#group5 {
    margin: 1px 2px;
}

#group6 {
    padding: 5px;
}