使用CSS绘制不规则形状的图形（应该响应）

Question

Is there any way to draw a shape (image below) with css? The grey border style should be dashed . And the most important is it should be responsive ( should adapt different size of screen with different radius ).

Bad example （not responsive）:

 #box { position: relative; margin: 30px; width: 200px; height: 100px; background: #fff; border: 1px dashed #333; } .corner { position: absolute; height: 10px; width: 10px; border: 1px dashed #333; background-color: #fff; } .top-left { top: -1px; left: -1px; border-radius: 0 0 100% 0; border-width: 0 1px 1px 0; } 

 <div id="box"> <div class="corner top-left"></div> </div> 

Answer 1

My advice is to go with SVG. It's what it's for. Here's an example...

<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" width="100%" viewBox="0 0 256 128" enable-background="new 0 0 256 128" xml:space="preserve">
    <path fill="#FFFFFF" stroke="#828282" stroke-dasharray="10" stroke-width="5" d="M249.75,121h-242V64c0,0,56.5,4.75,56.5-56.5h185.5V121z" />
</svg>

Fiddle: https://jsfiddle.net/6r0hhfsh/

Answer 2

I go with an answer since it seems my comment brought you some ideas.

The idea is based on ( codepen )

• Percentage vertical margin and padding to use width as reference.

  https://www.w3.org/TR/CSS2/box.html#padding-properties

• A background-gradient to draw the dashed curved (firefox is buggy there with dotted/dashed round borders)

  https://bugzilla.mozilla.org/show_bug.cgi?id=382721

• mix-blend-mode to blend pseudos parent and white background with the page.

  https://developer.mozilla.org/en-US/docs/Web/CSS/mix-blend-mode

  http://caniuse.com/#search=mix-blend-mode

• calc() to mix percentage and pixel to draw the curved border at around 15-20px width.

  https://www.w3.org/TR/css3-values/#calc-notation

 p { margin: 0; text-shadow: 0 0 1px; text-align:justify; } div { font-size:2em; width: 80%; background: white; margin: 10% 2em 2em 10%; padding: 15px; border: 15px dashed gray; position: relative; mix-blend-mode: multiply; } div:before { padding: calc(3% + 10px); float: left; content: ''; } div:after { position: absolute; content: ''; padding: 7%; border: inherit; border-radius: 50%; top: 0; left: 0; margin: calc(-10% - 7px); box-shadow: 0 0 0 15px white, inset 0 0 0 150px white; } div + div:after { background: url(http://lorempixel.com/250/250/people/6) center ; box-shadow: 0 0 0 15px white; } p:before { content: ''; border-radius: 50%; padding: calc(7% + 35px); position: absolute; background: repeating-linear-gradient(45deg, transparent 0, transparent 20px, gray 20px, gray 45px) bottom right no-repeat ; background-size: 35% 39.5%; top: -20px;; left: -20px; margin: -10% } body { background: url(http://lorempixel.com/640/480/nature/6) yellow; background-size: cover } 

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