.photo {

  margin: 0 auto;

width: 100%;
  /* état initial : noir et blanc */
  filter: grayscale(1) contrast(1.4) brightness(1.2);
  transition: filter 0.2s linear;
}

.photo_2 {

  margin: 0 auto;


  /* état initial : noir et blanc */
  filter: grayscale(0.0) contrast(1.5) brightness(1.0);
  transition: filter 0.2s linear;
	border-radius: 5px;
}