@starting-style with custom property
Dumping matched rules: 
*> div* {    regular
    padding: 10px; @[3:8-3:22]
    transition: color 1s ease, background-color 1s ease; @[4:8-4:60]
    display: inline-block; @[5:8-5:30]
    padding-top: 10px; @[undefined-undefined]
    padding-right: 10px; @[undefined-undefined]
    padding-bottom: 10px; @[undefined-undefined]
    padding-left: 10px; @[undefined-undefined]
    transition-behavior: normal, normal; @[undefined-undefined]
    transition-duration: 1s, 1s; @[undefined-undefined]
    transition-timing-function: ease, ease; @[undefined-undefined]
    transition-delay: 0s, 0s; @[undefined-undefined]
    transition-property: color, background-color; @[undefined-undefined]
    display: inline-block; @[undefined-undefined]
}
Dumping inherited rules: 
*body* {    regular
}