在三角形上创建边框

Question

我只想在每个列表元素后面的箭头（不是 div）上应用边框。目前它们是白色的，在此 fiddle.

中不可见

HTML:

<div class="content">
<div class="steps-container">
    <ol class="steps">
        <li class="step step1 current">
            <div class="step-content">
                <div class="step-number step-number-first">1</div>
                <span class="step-details">Step 1</span>
            </div>
        </li>
        <li class="step step2 ">
            <div class="step-content">
                <div class="step-number">2</div>
                <span class="step-details">Step 2</span>
            </div>
        </li>
        <li class="step step3 ">
            <div class="step-content">
                <div class="step-number">3</div>
                <span class="step-details">Step 3</span>
            </div>
        </li>
        <li class="step step4 ">
            <div class="step-content">
                <div class="step-number">4</div>
                <span class="step-details">Step 4</span>
            </div>
        </li>
    </ol>
</div>
</div>

CSS:

.steps-container {
  background-color: #ffffff;
  border-radius: 4px;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  -ms-border-radius: 4px;
  background-clip: padding-box;
  float: left;
  height: 52px;
  margin: 0;
  width: 100%;
}
.steps-container ol.steps {
  border-radius: 4px;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  -ms-border-radius: 4px;
  background-clip: padding-box;
  counter-reset: li;
  font-size: 9px;
  font-size: 0.9rem;
  line-height: 10px;
  list-style: none;
  margin: 0;
  overflow: hidden;
  padding: 0;
}
.steps-container ol.steps .step {
  box-sizing: border-box;
  height: 52px;
  width: 25%;
}
.steps-container ol.steps li {
  list-style-image: none;
  list-style-type: none;
  margin-left: 0;
  text-align: center;
  color: #c7c7c7;
  padding-top: 4px;
  background-color: #ffffff;
  position: relative;
}
.steps-container ol.steps li:after {
  position: absolute;
  top: -16px;
  left: 100%;
  content: " ";
  height: 0;
  width: 0;
  pointer-events: none;
  border: solid transparent;
  border-left-color: #ffffff;
  border-width: 26px 10px;
  margin-top: 16px;
  -webkit-filter: drop-shadow(5px 0 2px #f2f2f2);
  -moz-filter: drop-shadow 5px 0 2px #f2f2f2;
  -ms-filter: drop-shadow 5px 0 2px #f2f2f2;
  -o-filter: drop-shadow 5px 0 2px #f2f2f2;
  filter: drop-shadow 5px 0 2px #f2f2f2;
}
.steps-container ol.steps li:first-child {
  margin-left: 0;
}
.steps-container ol.steps li:first-child .step-details:after {
  border: none;
}
.steps-container ol.steps li:last-child:after {
  border-width: 0;
}
.steps-container ol.steps li .step-content {
  display: block;
  padding: 2px;
  margin-top: 10px;
}
.steps-container ol.steps li .step-content:before {
  counter-increment: li;
}
.steps-container ol.steps > li {
  float: left;
}
.steps-container ol.steps .step-number {
  border-radius: 50%;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  -ms-border-radius: 50%;
  background-clip: padding-box;
  background-color: grey;
  color: #ffffff;
  height: 16px;
  width: 16px;
  text-align: center;
  margin: 0 auto;
  float: left;
  line-height: 15px;
  margin-left: 15px;
}
.steps-container ol.steps li.current {
  color: #ffffff;
  background-color: grey;
}
.steps-container ol.steps li.current .step-number {
  background-color: #ffffff;
  color: #565656;
}
.steps-container ol.steps li.current:after {
  border-left-color: grey;
}
.steps-container ol.steps li.current:before {
  -webkit-filter: drop-shadow(0 0 0 transparent);
  -moz-filter: drop-shadow 0 0 0 transparent;
  -ms-filter: drop-shadow 0 0 0 transparent;
  -o-filter: drop-shadow 0 0 0 transparent;
  filter: drop-shadow 0 0 0 transparent;
}
.steps-container li.step1 {
  z-index: 3;
}
.steps-container li.step2 {
  z-index: 2;
}
.steps-container li.step3 {
  z-index: 1;
}
.steps-container li.step4 {
  z-index: 0;
}

@media screen and (max-width: 767px) {
  .step-number-first {
    margin-left: 8px;
  }
}
@media screen and (min-width: 768px) {
  .steps-container {
    height: 64px;
  }
  .steps-container ol.steps {
    font-size: 20px;
    font-size: 2rem;
  }
  .steps-container ol.steps .step {
    height: 64px;
  }
  .steps-container ol.steps .step-number {
    font-size: 22px;
    font-size: 2.2rem;
    font-size: 22px;
    left: 10px;
    height: 36px;
    line-height: 36px;
    position: absolute;
    top: 15px;
    width: 36px;
  }
  .steps-container ol.steps li {
    text-align: left;
  }
  .steps-container ol.steps li .step-content {
    margin-top: 20px;
  }
  .steps-container ol.steps li .step-details {
    margin-left: 65px;
  }
  .steps-container ol.steps li:after {
    border-width: 32px 15px;
  }
}

不想走旋转45度的路线

Answer 1

试试这个：

CSS

.steps-container {
  background-color: #ffffff;
  border-radius: 4px;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  -ms-border-radius: 4px;
  background-clip: padding-box;
  float: left;
  height: 52px;
  margin: 0;
  width: 100%;
}
.steps-container ol.steps {
  border-radius: 4px;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  -ms-border-radius: 4px;
  background-clip: padding-box;
  counter-reset: li;
  font-size: 9px;
  font-size: 0.9rem;
  line-height: 10px;
  list-style: none;
  margin: 0;
  overflow: hidden;
  padding: 0;
}
.steps-container ol.steps .step {
  box-sizing: border-box;
  height: 52px;
  width: 25%;
}
.steps-container ol.steps li {
  list-style-image: none;
  list-style-type: none;
  margin-left: 0;
  text-align: center;
  color: #c7c7c7;
  padding-top: 4px;
  background-color: #ffffff;
  position: relative;
    padding-left: 16px;
}
.steps-container ol.steps li:after {
  position: absolute;
  top: -16px;
  left: 100%;
  content: " ";
  height: 0;
  width: 0;
  pointer-events: none;
  border: solid transparent;
  border-left-color: #ffffff;
  border-width: 26px;
  margin-top: 16px;

  -webkit-filter: drop-shadow(5px 0 2px #f2f2f2);
  -moz-filter: drop-shadow 5px 0 2px #f2f2f2;
  -ms-filter: drop-shadow 5px 0 2px #f2f2f2;
  -o-filter: drop-shadow 5px 0 2px #f2f2f2;
  filter: drop-shadow 5px 0 2px #f2f2f2;
}


.steps-container ol.steps li:before {
  position: absolute;
  top: -16px;
  left: 100%;
  content: " ";
  height: 0;
  width: 0;
  pointer-events: none;
  border: solid transparent;
  border-left-color: #808080;
  border-width: 28px;
  margin-top: 22px;
  margin-top: 14px;
}

.steps-container ol.steps li:first-child {
  margin-left: 0;
}
.steps-container ol.steps li:first-child .step-details:after {
  border: none;
}
.steps-container ol.steps li:last-child:after {
  border-width: 0;
}
.steps-container ol.steps li .step-content {
  display: block;
  padding: 2px;
  margin-top: 10px;
}
.steps-container ol.steps li .step-content:before {
  counter-increment: li;
}
.steps-container ol.steps > li {
  float: left;
}
.steps-container ol.steps .step-number {
  border-radius: 50%;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  -ms-border-radius: 50%;
  background-clip: padding-box;
  background-color: grey;
  color: #ffffff;
  height: 16px;
  width: 16px;
  text-align: center;
  margin: 0 auto;
  float: left;
  line-height: 15px;
  margin-left: 15px;
}
.steps-container ol.steps li.current {
  color: #ffffff;
  background-color: grey;
}
.steps-container ol.steps li.current .step-number {
  background-color: #ffffff;
  color: #565656;
}
.steps-container ol.steps li.current:after {
  border-left-color: grey;
}
.steps-container ol.steps li.current:before {
  -webkit-filter: drop-shadow(0 0 0 transparent);
  -moz-filter: drop-shadow 0 0 0 transparent;
  -ms-filter: drop-shadow 0 0 0 transparent;
  -o-filter: drop-shadow 0 0 0 transparent;
  filter: drop-shadow 0 0 0 transparent;
}
.steps-container li.step1 {
  z-index: 3;
}
.steps-container li.step2 {
  z-index: 2;
}
.steps-container li.step3 {
  z-index: 1;
}
.steps-container li.step4 {
  z-index: 0;
}

@media screen and (max-width: 767px) {
  .step-number-first {
    margin-left: 8px;
  }
}
@media screen and (min-width: 768px) {
  .steps-container {
    height: 64px;
  }
  .steps-container ol.steps {
    font-size: 20px;
    font-size: 2rem;
  }
  .steps-container ol.steps .step {
    height: 64px;
  }
  .steps-container ol.steps .step-number {
    font-size: 22px;
    font-size: 2.2rem;
    font-size: 22px;
    left: 10px;
    height: 36px;
    line-height: 36px;
    position: absolute;
    top: 15px;
    width: 36px;
  }
  .steps-container ol.steps li {
    text-align: left;
  }
  .steps-container ol.steps li .step-content {
    margin-top: 20px;
  }
  .steps-container ol.steps li .step-details {
    margin-left: 65px;
  }
  .steps-container ol.steps li:after {
    border-width: 32px 15px;
  }
}

DEMO HERE

Answer 2

阴影技术

在 CSS 中创建三角形的典型方法（和您正在使用的方法相同）是使用边框技巧。使用该技术，有几种方法可以使您非常接近您想要的结果。这是我认为最简单的方法。

filter: drop-shadow(5px 0 0 #000);

通过应用带有一点偏移的不模糊投影，我们可以在右边缘创建边框。请注意，此技术使用阴影过滤器而不是框阴影（因为框阴影不会正确地包裹到三角形），因此需要一些供应商前缀才能获得可接受的浏览器支持。

演示版

这是一个可运行的演示，包括供应商前缀和适当的裁剪。如果有什么不对劲，请告诉我，我会改正。

这可以在没有 wrapper 元素的情况下完成（只需删除 wrapper div 和子元素上的边距），但它会在三角形的顶部和底部角附近有一个小间隙。

.triangle_wrapper {
  
  /* crop out the edges to remove the undesired gap */
  height: 40px;
  overflow: hidden;
  
}
.triangle-right {
  
  /* give a little offset, so the wrapper can crop it properly */
  margin-top: -5px;
  margin-left: -5px;
  
  /* border-hack triangles need no width or height */
  width: 0;
  height: 0;
  
  /* this makes the triangle */
  border-left: 25px solid #ff0000;
  border-top: 25px solid transparent;
  border-bottom: 25px solid transparent;
  
  /* this adds the border */
  filter: drop-shadow(5px 0 0 #000);
  -webkit-filter: drop-shadow(5px 0 0 #000);
  filter: progid: DXImageTransform.Microsoft.Shadow(Strength=0, offX=5px, offY=0px, Color='#000000');
  -ms-filter: "progid:DXImageTransform.Microsoft.Shadow(Strength=0, offX=5px, offY=0px, Color='#000000')";
  
}

<div class="triangle_wrapper">
  <div class="triangle-right"></div>
</div>

在三角形上创建边框

Create a border on a triangle

html

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css-shapes