How to split page background with vertical polyline?

Question

I found how to split page with vertical line - see jsfiddle:

The code is below -

body {
    background-color: white;
}

#background {
    position: fixed;
    top: 0px;
    left: 0px;
    width: 50%;
    height: 100%;
    background-color: black;
    z-index: 1;
}

#content {
    position: relative;
    z-index: 2;
    padding: 30px;
    text-align: center;
    font-weight: bold;
    color: red; 
    font-family: Arial, sans-serif;
}

Now I would like to replace vertical line with polyline to get something like this:

How can I do it with CSS?

P.S. I can not use background image, since polyline can be different (the points will have different coordinates).

user_8620333 · Answer

You can consider multiple background to achieve this but it may be tricky to find the different values depending on the shape. It's basically a combination of triangle shape and rectangle shape above each other to create the final layer (changing the colors will help you identify each one)

body {
  margin:0;
}
.box {
  height:100vh;
  background:
    linear-gradient(to bottom right,#000 49.8%,transparent 50%) 0 0/70% 120%,
    linear-gradient(to top right,#000 49.8%,transparent 50%) 0 0/60% 70%,
    linear-gradient(#000,#000) 0 100%/50% 31%,
    linear-gradient(to bottom right,#000 49.8%,transparent 50%) 55.3% 100%/10% 30.2%;
  background-repeat:no-repeat;
}

You can also consider clip-path within a pseudo element and it will be easier (https://bennettfeely.com/clippy/)

body {
  margin:0;
}
.box {
  height:100vh;
  position:relative;
}
.box:before {
  content:"";
  position:absolute;
  top:0;
  left:0;
  bottom:0;
  right:20%;
  background:#000;
  -webkit-clip-path: polygon(0 0, 72% 0, 59% 33%, 68% 62%, 47% 100%, 0 100%);
clip-path: polygon(0 0, 72% 0, 59% 33%, 68% 62%, 47% 100%, 0 100%);
}

How to split page background with vertical polyline?

1 Answers