<input type="range" min="0" max="10" step="0.1" value="1">

<div class="container">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>        
</div>

.container {
  display: grid;
  grid-template-columns: repeat(3, 100px);
  grid-auto-rows: 100px;
  justify-content: space-between;
  align-content: space-between;
  gap: 1rem;
  width: 100%;
  max-width: 37.5rem;
  min-height: 20rem;
  padding: 0.5rem;
  margin: 0 auto;
  box-sizing: border-box;
  border: 2px dashed #fdeae3;
  border-radius: 15px;
}

body {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin: 0;
  min-height: 100vh;
  background: linear-gradient(-45deg, #ff9f4d 10%, #ffc857 0, #ffc857 90%, #ff9f4d 0, #ff9f4d 100%);
}

input[type="range"] {
  display: block;
  margin: 2rem auto;
}

.item {
  border-radius: 15px;
  background-color: #faf7fa;
  background-image: linear-gradient(#ff5e49,#ff5e49), linear-gradient(#4d004c,#4d004c);
  background-size: 50px 10px, 60px 10px;
  background-position: 20px 40px, 20px 60px;
  background-repeat: no-repeat;
}



@supports not (gap: 1px) {
  body {
    padding-top: 2em;  
  }
  
  body::before {    
    content: "Your browser doesn't support gap property";
    display: block;
    color: #e43;
    font-weight: bold;
    position: fixed;
    top: 1.5em;
    left: 0;
    right: 0;
    z-index: 1;
    text-align: center;
  }
}

var container = document.querySelector('.container'),
    slider = document.querySelector('input');

slider.addEventListener('input', function () {
  container.style.gap = this.value + 'rem';
}, false);