1.bulb svg {
2  display: block;
3  height: 90px;
4  transform-origin: center top;
5  animation: swing_31 1.3s ease-in-out infinite alternate;
6}
7
8@keyframes swing_31 {
9  0% {
10    transform: rotate(18deg);
11  }
12
13  100% {
14    transform: rotate(-18deg);
15  }
16}