How to add a border to a jagged border container

Hello I am having trouble trying to come up with a way of adding a border of 1px to a container with a jagged border such as:

https://codepen.io/swizenfeld/pen/ZyBybW

body {
  background: #f4f4f4;
}
.edge {
  width: 100%;
  height: 400px;
  background: #fff;
  margin-top: 30px;
}
.edge:before {
    content: " ";
    display: block;
    position: relative;
    width: 100%;
    top:-30px;
    height:30px;
    background: linear-gradient(135deg, transparent 75%, white 76%) 0 50%,
                linear-gradient(-135deg, transparent 75%, white 76%) 0 50%;
    background-repeat: repeat-x;
    background-size: 30px 30px, 30px 30px;
}

<div class="edge"></div>

Any ideas?

Solution

You need to add more linear-gradient() to show jagged border

body {
  background: #f4f4f4;
}
.edge {
  width: 100%;
  height: 400px;
  background: #fff;
  margin-top: 30px;
}
.edge:before {
    content: " ";
    display: block;
    position: relative;
    width: 100%;
    top:-30px;
    height:30px;
    background: linear-gradient(135deg, transparent 75%, white 76%) 0 50%, linear-gradient(-135deg, transparent 75%, white 76%) 0 50%, linear-gradient(45deg, red 30%, transparent 0%), linear-gradient(-45deg, red 30%, transparent 0%);
    background-repeat: repeat-x;
    background-size: 30px 30px, 30px 30px;
}

<div class="edge"></div>

For border-left, -bottom, -right, try to play with below snippet and see the comment also given for css properties.

body {
  background: #ccc;
}
.edge {
  width: 100%;
  height: 400px;
  background: white;
  margin-top: 30px;
  border-left:2px solid red;
  border-bottom:2px solid red;
  border-right:2px solid red;
  position:relative;    /*make it relative*/
}
.edge:after {
    content: " ";
    display: block;
    position:absolute; /*make it absolute*/
    width: 100%;
    top:-6px;  /* play with top and height too*/
    height:23px;
  /*background: linear-gradient(135deg, transparent 75%, white 76%) 0 50%, linear-gradient(-135deg, transparent 75%, white 76%) 0 50%, linear-gradient(45deg, red 30%, transparent 0%), linear-gradient(-45deg, red 30%, transparent 0%);*/
    background: linear-gradient(45deg,white 14px, red 16px, transparent 17px), linear-gradient(-45deg, white 14px, red 16px, #ccc 17px);

    background-repeat: repeat-x;
    background-size: 30px 30px, 30px 30px;

}

<div class="edge"></div>