Create wavy borders in CSS for top and bottom borders

问题

I'm trying to create a wavy top and bottom border like the image here

I tried recreating the same effect using the following code

.wave{
  background: white;
  height: 25px;
  position: relative;  
}
.wave::before, .wave::after{
  border-bottom: 5px solid rgba(237, 30, 30, 1);
}
.wave::before{
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 12px;
  background-size: 20px 40px;
  background-image:
    radial-gradient(circle at 10px -15px, transparent 20px, rgba(237, 30, 30, 1) 21px);
}
.wave::after{
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 18px;
  background-size: 40px 40px;
  background-image:
    radial-gradient(circle at 10px 26px, rgba(237, 30, 30, 1) 20px, transparent 21px);
}


.wavebottom{
  background: rgba(237, 30, 30, 1);
  height: 25px;
  position: relative;  
}
.wavebottom::before, .wave::after{
  border-bottom: 5px solid rgba(237, 30, 30, 1);
}
.wave::before{
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 12px;
  background-size: 20px 40px;
  background-image:
    radial-gradient(circle at 10px -15px, transparent 20px, white 21px);
}
.wavebottom::after{
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 18px;
  background-size: 40px 40px;
  background-image:
    radial-gradient(circle at 10px 26px, white 20px, transparent 21px);
}

Where I have the code in 3 divs.. first div has the wave class

second div has the background color and the content

and the third div has the wavebottom class

but I'm getting the results of the waves looking like that

I'm working on a page with the width of 1920px, I'm not sure how can I make this look the same like the first image

回答1:

Try using this:

.wave-top {
  position: relative;
  margin-top: 20px;
}

.wave-top::before,
.wave-top::after {
  border-bottom: 5px solid rgba(237, 30, 30, 1);
}

.wave-top::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 10px;
  background-size: 20px 40px;
  background-image: radial-gradient(circle at 10px -15px, transparent 20px, rgba(237, 30, 30, 1) 21px);
}

.wave-top::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 15px;
  background-size: 40px 40px;
  background-image: radial-gradient(circle at 10px 26px, rgba(237, 30, 30, 1) 20px, transparent 21px);
}

.wave-mid {
  background-color: rgba(237, 30, 30, 1);
  height: 50px;
}

.wave-bottom {
  position: relative;
}

.wave-bottom::before,
.wave-bottom::after {
  border-top: 5px solid rgba(237, 30, 30, 1);
}

.wave-bottom::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 10px;
  background-size: 20px 40px;
  background-image: radial-gradient(circle at 10px -15px, transparent 20px, #fff 21px);
}

.wave-bottom::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 15px;
  background-size: 40px 40px;
  background-image: radial-gradient(circle at 10px 26px, #fff 20px, transparent 21px);
}

<div class='wave-top'></div>
<div class="wave-mid"></div>
<div class="wave-bottom"></div>

You can increase the height of the middle-div according to your need. Here I have kept it 50px

来源：https://stackoverflow.com/questions/56407055/create-wavy-borders-in-css-for-top-and-bottom-borders

标签

html

css

border