* {
  margin: 0;
  background: linear-gradient(to right,black, grey);
}
h1 {
  text-align: right;
  margin-top: 30px;
  margin-right: 40px;
  font-size: 40px;
  font-family: system-ui ;
  color: black;

}
.gallery {
  height: 80;
  width: 100%;
  display: flex;
  margin: 5% auto 0;
  box-sizing: border-box;
}
.image-box {
  margin: 0 1%;
  flex-grow: 1;
  flex-basis: 0;
  transition: 0.5s;
}
.image-box img {
  width: 100%;
  height: 500%;
  object-fit: cover;
  transition: 0.5s;
}
.image-box:hover {
  flex-basis: 50%;
}
.active {
  flex-basis: 50%;
}
.gallery:hover .active {
  flex-basis: 0;
}
.image-box:nth-child(1):hover {
  flex-basis: 50%;
}