<div class="outer-container">
  <div class="inner-container">
    <div class="inner-item">Item 1</div>
    <div class="inner-item">Item 2</div>
  </div>
  <div class="inner-container">
    <div class="inner-item">Item 3</div>
    <div class="inner-item">Item 4</div>
  </div>
</div>

/* Outer container for nesting */
.outer-container {
  display: flex;
  justify-content: space-around;
  align-items: center;
  height: 300px;
  background-color: #f0f0f0;
  padding: 10px;
}

/* Inner flex containers */
.inner-container {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  background-color: #007bff;
  padding: 10px;
  width: 120px;
  height: 200px;
  border-radius: 5px;
  color: white;
}

/* Individual items inside inner containers */
.inner-item {
  background-color: #28a745;
  padding: 10px;
  border-radius: 3px;
  width: 80px;
  text-align: center;
}