.container {
  width: 100%;
}

.atelier-row {
  margin-left: auto;
  margin-right: auto;
  padding: 0;
  border: none;
  box-sizing: border-box;
}

@media all and (max-width: 900px) {
  .atelier-row {
    width: 100%;
  }

  .atelier-img-block {
    height: 200px;
  }

  .atelier-img {
    width: 33.33%;
    padding-top: 33.33%;
    float: left;
    background-size: cover;
  }
}

@media all and (min-width: 900px) and (max-width: 1200px) {
  .atelier-row {
    width: 900px;
  }

  .atelier-img-block {
    height: 300px;
  }

  .atelier-img {
    width: 33.33%;
    padding-top: 33.33%;
    float: left;
    background-size: cover;
  }
}

@media all and (min-width: 1200px) {
  .atelier-row {
    width: 1100px;
  }

  .atelier-img-block {
    height: 400px;
  }

  .atelier-img {
    width: 33.33%;
    padding-top: 400px;
    float: left;
    background-size: cover;
  }
}
