#gallery{
overflow: hidden;
}
.gallery {
background-color:#f2f2f2;
width:100%;
  display: grid;
  place-items: center;
}


.slider {
  width: 100%;
  max-width: 800px;
  height: 500px;
  position: relative;
/*  overflow: hidden;  /* <===  */
  border-radius: 15px;
}


.slide {
  width: 100%;
  max-width: 800px;
  height: 500px;
  position: absolute;
  transition: all 0.5s;
}

.slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.btn {
  position: absolute;
  width: 40px;
  height: 40px;
  padding: 10px;
  border: none;
  border-radius: 50%;
  z-index: 10px;
  cursor: pointer;
  background-color: #fff;
  font-size: 18px;
}

.btn:active {
  transform: scale(1.1);
}

.btn-prev {
  top: 45%;
  left: 2%;
}

.btn-next {
  top: 45%;
  right: 2%;
}