Is there a way to add a border to a CSS clipping without HTML

Im trying to find out if there is a way to add a border to a clipped path using only CSS code. This is what I am currently working with, unfortunately im doing all of this inside of sqaurespace and im not able to add html code to a page for something like this unless im completely missing it. Any help is much appreciated.

#collection-603b5312dea190701aa09362 { 


#page .page-section:nth-of-type(3) { 
    -webkit-clip-path: polygon(0 35%, 100% 6%, 100% 100%, 0 80%);
    clip-path: polygon(0 35%, 100% 6%, 100% 100%, 0 80%);
  .border-style-thin {
  background-color: #FFFFFF;
  background-color: rebeccaPurple;
}
    .border-style-thin:after {  
  top: 3px;
  left: 3px;
  right: 3px;
  bottom: 3px;
}
  } 
}