CODE EXAMPLE FOR CSS

flex box css

.flex-container {
  display: flex;
  flex-wrap: wrap;
  background-color: DodgerBlue;
}

//for box set in column:
.flex-container {
  display: flex;
  flex-direction: column;
//set div in column in reverse:
  .flex-container {
  display: flex;
  flex-direction: column-reverse;
//wrap in raw:
    .flex-container {
  display: flex;
  flex-flow: row wrap;
//make all div in center:
      .flex-container {
  display: flex;
  justify-content: center;
//set all div in flex-box hight in strech:
.flex-container {
  display: flex;
  height: 200px;
  align-items: stretch;
// for responsive view:
  .flex-container {
  display: flex;
  flex-direction: row;
  font-size: 30px;
  text-align: center;
}

.flex-item-left {
  background-color: #f1f1f1;
  padding: 10px;
  flex: 50%;
}

.flex-item-right {
  background-color: dodgerblue;
  padding: 10px;
  flex: 50%;
}

/* Responsive layout - makes a one column-layout instead of two-column layout */
@media (max-width: 800px) {
  .flex-container {
    flex-direction: column;
  }
}
//trasition property:
  div {
  width: 100px;
  height: 100px;
  background: red;
  transition: width 2s;
}

div:hover {
  width: 300px;
}