gtk2/testsuite/css/parser/integer.ref.css

a {
  opacity: 0;
}

b {
  opacity: 1;
}

c {
  opacity: -1;
}

d {
  opacity: 2147483647;
}

e {
  opacity: -2147483648;
}

f {
  opacity: 1;
}

i {
  opacity: 377;
}

l {
  opacity: 3;
}