input.css

@supports (width: calc(100px + 100px)) {
    div {
        background: red;
    }
}

@supports (width: calc(calc(100px + 100px))) {
    div {
        background: red;
    }
}

@supports (width: calc(0px * 100)) {
    div {
        background: red;
    }
}

@supports (width: calc(0px + 0px)) {
    div {
        background: red;
    }
}

@supports (width: calc(100px * sqrt(9))) {
    div {
        background: red;
    }
}