details .plus {
    transform: translate3d(0px, 0px, 0px) scale3d(1, 1, 1) rotateX(0deg) rotateY(0deg) rotateZ(90deg) skew(0deg);
    transform-style: preserve-3d;
}

details[open] .plus {
    transform: translate3d(0px, 0px, 0px) scale3d(1, 1, 1) rotateX(0deg) rotateY(0deg) rotateZ(0deg) skew(0deg);
}