How to make arc shapes with CSS3?

问题:

I'm trying to achieve following look, with pure css:

Where each white arc is a different element, say span. I know we can make round shapes with css, but how can it be turned into arc sort of shape?

回答1:

With the following HTML:

<div id="arcs">
    <div>
        <div>
            <div>
                <div></div>
            </div>
        </div>
    </div>
</div>

And the CSS:

#arcs div {
    border: 2px solid #000; /* the 'strokes' of the arc */
    display: inline-block;
    min-width: 4em; /* the width of the innermost element */
    min-height: 4em; /* the height of the innermost element */
    padding: 0.5em; /* the spacing between each arc */
    border-radius: 50%; /* for making the elements 'round' */
    border-top-color: transparent; /* hiding the top border */
    border-bottom-color: transparent;
}

#arcs div {
  border: 2px solid #000;
  /* the 'strokes' of the arc */
  display: inline-block;
  min-width: 4em;
  /* the width of the innermost element */
  min-height: 4em;
  /* the height of the innermost element */
  padding: 0.5em;
  /* the spacing between each arc */
  border-radius: 50%;
  /* for making the elements 'round' */
  border-top-color: transparent;
  /* hiding the top border */
  border-bottom-color: transparent;
}

<div id="arcs">
  <div>
    <div>
      <div>
        <div></div>
      </div>
    </div>
  </div>
</div>

JS Fiddle demo.

回答2:

SVG Approach:

I would recommend you to use SVG to draw such shapes:

In the example below I've used SVG's path element to draw an arc. This element takes single attribute d to describe the shape structure. d attributes takes a few commands and corresponding necessary parameters.

I've used only 2 path commands:

• M command is used to move the pen to a specific point. This command takes 2 parameters x and y and usually our path begins with this command. It basically defines starting point of our drawing.
• A command which is used to draw curves and arcs. This commands takes 7 parameters to draw an arc / curve. A detailed explanation of this command is Here.

Screenshot:

Useful Resources:

• Specification
• MDN

Working Example:

svg {
  width: 33%;
  height: auto;
}

<svg viewBox="0 0 300 300" xmlns="http://www.w3.org/2000/svg">

  <defs>
    <g id="arcs" fill="none" stroke="#fcfcfc">
      <path d="M80,80 A100,100,0, 0,0 80,220" stroke-width="4" />
      <path d="M90,90 A85,85,0, 0,0 90,210" stroke-width="3.5" />
      <path d="M100,100 A70,70,0, 0,0 100,200" stroke-width="3" />
      <path d="M110,110 A55,55,0, 0,0 110,190" stroke-width="2.5" />
    </g>
  </defs>
  
  <rect x="0" y="0" width="300" height="300" fill="#373737" />

  <use xlink:href="#arcs" />
  <use xlink:href="#arcs" transform="translate(300,300) rotate(180)" />
  
</svg>