* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
}

body {
  background-image: radial-gradient(#bb9927, #634a1a);
}

header {
  position: relative !important;
}

.gallery {
  display: flex;
  padding: 2px;
  transition: 0.3s;
}

/* Le immagini diventato tutte grigie */
.gallery:hover .gallery__image {
  filter: grayscale(1);
}

/* Allineamento delle varie colonne */
.gallery__column {
  display: flex;
  flex-direction: column;
  width: 25%;
}

.gallery__link {
  margin: 2px;
  overflow: hidden;
}

/* Al passare del mouse le immagine prendono colore */
.gallery__link:hover .gallery__image {
  filter: grayscale(0);
}
.gallery__link:hover .gallery__caption {
  opacity: 1;
}

.gallery__thumb {
  position: relative;
}

.gallery__image {
  display: block;
  width: 100%;
  transition: 0.3s;
}

.gallery__image:hover {
  transform: scale(1.1);
}

@media only screen and (max-width: 980px) {
  /* Le immagini vanno una sotto l'altra */
  .gallery {
    display: inherit;
  }

  /* Le immagini diventano a tutto schermo */
  .gallery__column {
    display: inherit;
    width: 100%;
  }

  .gallery__image {
    padding-bottom: 5px;
  }

  .gallery__image:hover {
    transform: scale(1);
  }
}