JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box">
  <div class="box__items">1</div>
  <div class="box__items">2</div>
  <div class="box__items">3</div>
  <div class="box__items">4</div>
  <div class="box__items">5</div>
  <div class="box__items">6</div>
  <div class="box__items">7</div>
</div>

CSS

.box {
    display: grid;
    margin: 10px;
    border-top: 4px solid #96ceb4;
    border-right: 4px solid #96ceb4;
    grid-template-columns: repeat(3, 1fr);
    grid-auto-rows: minmax(50px, auto);
}

.box__items {
    display: flex;
    color: #96ceb4;
    border-bottom: 4px solid #96ceb4;
    border-left: 4px solid #96ceb4;
    background-color: #ffeead;
    align-items: center;
    justify-content: center;
}

.box__items:nth-child(1) {
    grid-row: 1 / 4;
    grid-column: 1;
}

.box__items:nth-child(2) {
    grid-row: 1 / 3;
    grid-column: 2;
}

.box__items:nth-child(3) {
    grid-row: 1 / 4;
    grid-column: 3;
}

.box__items:nth-child(4) {
    grid-row: 4 / 7;
    grid-column: 1;
}

.box__items:nth-child(5) {
    grid-row: 3 / 7;
    grid-column: 2;
}

.box__items:nth-child(6) {
    grid-row: 4 / 6;
    grid-column: 3;
}