chromium/third_party/blink/web_tests/inspector-protocol/css/resources/coverage.css

body {background-color: lightblue;}
.class {color: red;}
#id {color: blue}
notUsed {color: black}
@media screen and (min-width: 480px) {
    body {
        background-color: lightgreen;
    }
}
@import "mystyle.css";
@keyframes mymove {
    0%   {top: 0px;}
    25%  {top: 200px;}
    75%  {top: 50px}
    100% {top: 100px;}
}
div {
    width: 100px;
    height: 100px;
    background: red;
    position :relative;
    -webkit-animation: mymove 5s infinite; /* Safari 4.0 - 8.0 */
    animation: mymove 5s infinite;
}

@supports (display: block) {
    .unused {
        display: block;
    }
    .class {
        display: block;
    }
}