html, body {
  height: 100%;
}
body {
  margin: 0;
}
.flex-container {
  height: 100%;
  padding: 0;
  margin: 0;
  display: -webkit-box;
  display: -moz-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
}
.row {
  width: auto;
  margin: 5;
}
.flex-item {
  /* background-color: tomato; */
  padding: 5px;
  width: 200px;
  height: 200px;
  margin: 10px;
  line-height: 20px;
  /* color: white; */
  font-size: 2em;
  text-align: center;
  border: 1px solid rgb(42, 42, 44);
  border-radius: 5px;
}

/* .flex-item:hover {
  background-color: yellow;
} */

img {
  max-width: 100%;
  max-height: 100%;
}