.postits {
  display: flex;
  flex-wrap: wrap;
  flex-direction: wrap;
  justify-content: center;
  background: white;
  overflow: hidden;
  margin: 5px;
  padding: 0.25vw;
  max-width: 90vw;
}
.content {
  padding: 0.5em;
  display: flex;
  flex-direction: column;
  align-items: center;
}

img {
  max-width: 100%;
}

#note1 {
  width: 250px;
}

#note2 {
  width: 250px;
}

#note3 {
  width: 250px;
}

#note4 {
  width: 250px;
}

@media (min-width: 576px) {
  .postit {
    max-width: 40vw;
  }
}
@media (min-width: 768px) {
  .postit {
    max-width: 20vw;
  }
}