body {
  background: rgb(161,209,249);
  /* https://cssgradient.io/ */ 
  background: radial-gradient(circle, rgba(161,209,249,1) 0%, rgba(144,168,173,1) 52%, rgba(250,247,247,1) 100%);
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

#container {
  height: 520px;
  width: 920px;
}

#slider {
  display: flex;
  box-shadow: 0 3px 5px rgba(0,0,0,0.6);
  border-radius: 20px;
  box-sizing: border-box;
}

nav {
  width: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgb(199,197,197);
  border-radius: 20px 0 0 20px;
}

#ra {
  transform: rotate(180deg);
}

#ra, #la {
  width: 160px;
}

#ra img, #la img {
  width: 40px;
}

#photo-container {
  position: relative;
  /* az alsó szürke csík kiküszöbölésére, de nem mindegyik képnél */
  height: 365px;
}

#gray-container {
  position: absolute;
  bottom: 0;
  background-color: rgba(0,0,0,0.4);
  color: white;
  padding: 0 20px;
}

#thumbnails {
  display: flex;
  justify-self: center;
  align-items: center;
  gap: 10px;
  padding-left: 78px;
}

.thumbnail {
  margin-top: 20px;
  width: 70px;
  height: 70px;
  border: 3px solid white;
  overflow: hidden; /* ami benne van, de túlcsordul, az nem fog látszani */
  box-shadow: 0 15px 15px -10px black;
}

.thumbnail > img {
  height: 100%
}

.thumbnail:hover #photo-title {
  display: block;
}