<div class="w300">
  <div class="w100"></div>
  <div class="w100 red"></div>
  <div class="w100"></div>
</div>

<div class="wrapper">
  <div class="item"></div>
  <div class="item red center"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item red center"></div>
</div>
.w300 {
  display: flex;
  width: 100%;
}

.w100 {
  width: 100px;
  height: 100px;
  background-color: #eee;
}

.wrapper {
  display: inline-grid;
  grid-template-columns: 92.5px 95px 92.5px;
  border: 5px solid black;
  grid-gap: 5px;
  background-color: black;
}

.item {
  width: 92.5px;
  height: 92.5px;
  background-color: #eee;
}

.red {
  background-color: #f99;
}

.center {
  width: 95px;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.