<!doctype html>
<style>
  body {
    --peek: LightGreen;
    --border: transparent;
    margin:0;
  }
  .bg {
    background-color: var(--peek);
    background-image: linear-gradient(45deg, orange 0px, orange 5px, gainsboro 3px, gainsboro 25%, rgba(160,160,160,0.5) 25%, rgba(160,160,160,0.5) 50%, silver 50%, silver 75%, darkgray 75%, darkgray 99%, blue 99%);
    background-size: 200px 50px;
    background-repeat: no-repeat; /* FF defaults to no-repeat, Chrome to repeat */
  }
  main > * {
    box-sizing: border-box;
  }
  .table {
    width: 200px;
    position: relative;
    margin-top: 5px;
    margin-left:5px;
  }
  .row {
    width: 200px;
    height: 50px;
  }
  .cell {
    width: 50px;
    height: 50px;
    display: inline-block;
    vertical-align: top;
  }
  .bigsquarecell {
    width: 100px;
    height: 100px;
    display: inline-block;
    vertical-align: top;
    background-position-x: -50px;
  }
  .c2 {
    background-position-x: -50px
  }
  .c3 {
    background-position-x: -100px;
  }
  .c4 {
    background-position-x: -150px;
  }
  .bottomrow > .cell {
    margin-top: 5px;
  }
</style>
<main>
<div class="table">
<div class="row bg"></div>
<div><div class="cell firstcell bg"></div><div class="bigsquarecell bg"></div><div class="cell c4 bg"></div></div>
<div class="row bg"></div>
<div style="position:absolute;top:-5px;left:-5px;bottom:-5px;right:-5px;border: 10px solid var(--border)"></div>
</div>
</main>
