Overlapping circles in CSS with 1 div

Solution 1:

With CSS box-shadows

You can use multiple box-shadows with several colours on a rounded div. They need to be seperated by a comma:

#circles {
  background-color: red;
  width: 100px;
  height: 100px;
  border-radius: 50%;
  box-shadow: 10px 0 0 -2px #f8ff00,
              20px 0 0 -4px #009901,
              30px 0 0 -6px #3531ff;
}

<div id="circles"></div>

output :

CSS orvelapping circles

Browser support for box-shadows is IE9+ (for more info see canIuse)

You can also make the overlapping circles shape responsive according to the width of the viewport with vw units : DEMO

#circles {
  background-color: red;
  width: 20vw;
  height: 20vw;
  margin: 0 auto;
  border-radius: 50%;
  box-shadow: 2vw 0 0 -0.4vw #f8ff00, 
              4vw 0 0 -0.8vw #009901, 
              6vw 0 0 -1.2vw #3531ff;
}

<div id="circles"></div>

Browser support for vw units is IE9+ (for more info see canIuse)

With SVG

Another approach would be to use an inline svg with the <circle> element.
This is responsive according to the size of the parent and browser support goes back to IE9 like box-shadows :

svg{width:80%;}

<svg viewbox="0 0 100 30">  
  <circle cx="59" cy="15" r="8.5" fill="darkorange" />
  <circle cx="56" cy="15" r="9" fill="gold" />
  <circle cx="53" cy="15" r="9.5" fill="tomato" />
  <circle cx="50" cy="15" r="10" fill="teal" />
</svg>

I also expanded on the SVG version to make an animated "worm" with more overlapping circles. You can see it in this pen : animated worm

And it looks like this :

Animated worm made of overlapping circles

Solution 2:

It is possible to use CSS3 multiple background images and radial gradients together:

#circles {
  width: 115px;
  height: 100px;
  background-image:
    radial-gradient(circle at 50px 50px, #F00 0, #F00 50px, transparent 50px),
    radial-gradient(circle at 55px 50px, #FF0 0, #FF0 50px, transparent 50px),
    radial-gradient(circle at 60px 50px, #080 0, #080 50px, transparent 50px),
    radial-gradient(circle at 65px 50px, #00F 0, #00F 50px, transparent 50px);
}

<div id="circles"></div>

Solution 3:

Or, if you're feeling crazy, you could make an svg and use it inline as a background image:

#circles {
  width: 120px;
  height: 100px;
  background-image: url("data:image/svg+xml;utf8,<svg version='1.1' xmlns='http://www.w3.org/2000/svg' width='100%' height='100%'><circle fill='blue'  cy='50' cx='70' r='50' /><circle fill='green'  cy='50' cx='65' r='50' /><circle fill='yellow'  cy='50' cx='60' r='50' /><circle fill='red'  cy='50' cx='55' r='50' /></svg>");
}

<div id="circles"></div>

Solution 4:

You can achieve this by pseudo-selectors like ::before and::after, You can find the jsfiddle https://jsfiddle.net/zakirshaik/jL78m9d1/6/.

You can add shadows to the code to increase the number of circles.

.circle-overlaping{
  width: 100px;
  height: 100px;
  background-color: red;
  border-radius: 50%;
  position:relative;
}

.circle-overlaping::before{
  content: '';
  position: absolute;
  top: 0;
  left: 20px;
  background-color: yellow;
  width: 100px;
  height:100px;
  border-radius: 50%;
}

.circle-overlaping::after{
  content: '';
  position: absolute;
  top: 0;
  left: 40px;
  background-color: blue;
  width: 100px;
  height:100px;
  border-radius: 50%;
}

<div class="circle-overlaping">

</div>