Problem 3 for this code: how do I make the bullet go slowly to the side? (Like transition duration but for Javascript.)

Question

https://code.sololearn.com/Wh9tG53eUjuJ/?ref=app

Answer 1

/* for example: */
.bullet {
position:absolute;
top:3%;
width:20px;
height:11px;
background-color:#666;
border-radius:0 50% 50% 0;
transition-duration:1s;
animation-name: anim1;
animation-duration: 2s;
}
@keyframes anim1 {
from {left: 4%;}
to {left: 94%;}
}

Answer 2

https://code.sololearn.com/W897Yuf54V4Y/?ref=app