Translucid border
Using padding + outline
by Hugo Vale Pereira
HTML
<div class="pai">
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
<div class="a"></div>
</div>
SASS
div.pai
display: flex
gap: 10px
width: 400px
height: 400px
overflow: scroll
border-radius: 70px
padding: 50px
outline-offset: -50px
outline: 50px solid rgba(200,100,150,0.6)
background-color: blue
.a
flex: 0 0 100px
width: 100px
height: 100px
background: red