How to create a Slanted Background with CSS? [duplicate]

Answer 1

.left-sidebar {
  position: absolute;
  width: 20%;
  background: #000;
  transform: skewY(5px);
}
.content {
  background: #fff;
}

The property that "curves" the div is this property in CSS transform: skew(X,Y).Try that, hope it helps.

But I suggest that you create 2 div side-by-side in order to get the desired effect.

Answer 2

You can use pseudo element with skew transformation :

body {
  height: 100vh;
  margin: 0;
  background: yellow;
}

body:before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 300px;
  background: #000;
  transform: skew(-30deg);
  transform-origin:top;
}

To keep the same visual on resize, set a big fixed height for the pseudo element and center it:

html {
  background: yellow;
}

html:before {
  content: "";
  position: fixed;
  top: calc(50% - 1000px);
  left: 0;
  width: 500px;
  height:2000px;
  background: #000;
  transform: skew(-15deg);
  transform-origin:top;
}

Answer 3

Use a linear gradient at an angle

body {
 margin:0;
 }

div {
  height: 100vh;
  background: linear-gradient(105deg, black 25%, yellow 25%)
}

<div></div>