v-layout

<section class="container1"><div>10 percent</div><div>20%</div><div>fluid</div><div>2em</div></section>

.container1 {
  width: 400px;
  height: 300px;
  position: relative;
  v-layout: 10% 20% fluid 2em
}

.container2 {
  width: 400px;
  height: 300px;
  position: relative;
  v-layout: full-width 80px 30px 10px fluid
}

.container3 {
  width: 400px;
  height: 300px;
  position: relative;
  v-layout: full-width 10% 30% fluid-gap 30px 60px
}

.container4 {
  width: 400px;
  height: 300px;
  position: relative;
  v-layout: full-width fluid-gap 50px 80px 30px 10px
}