html - CSS重叠透明箭头元素

Question

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Answer 1

如果您不需要每个元素周围的黑色边框(如发布的图片所示)，您仍然可以通过 border 创建所需的形状，如下所示:

.timeline-unit:before, .timeline-unit:after {
    top: 0;
    border: solid transparent;
    border-width: 1.65em;
    height: 0;
    width: 0;
    position: absolute;
    pointer-events: none;
}

.timeline-unit:after {
    content: " ";
    left: 100%;
    border-left-color: rgba(51, 51, 51, 0.8);
}

.timeline-unit {
    position: relative;
    display: inline-block;
    background: rgba(51,51,51,.8);
    padding: 1em;
    line-height: 1.25em;
    color: #FFF;
}

.timeline-unit:before { content: none; }

.timeline-unit + .timeline-unit:before {
    content: " ";
    border-color: rgba(51, 51, 51, 0.8);
    border-left-color: transparent;
    border-right: 0;
    right: 100%;
}

.timeline-unit + .timeline-unit {
    margin-left: 2em;
}

/**************  D E M O  **************/

body {
  background: red;
    
  -webkit-animation: bgcolor 4s linear 0s infinite alternate;
     -moz-animation: bgcolor 4s linear 0s infinite alternate;
       -o-animation: bgcolor 4s linear 0s infinite alternate;
          animation: bgcolor 4s linear 0s infinite alternate;
}

@-webkit-keyframes bgcolor { from { background: red; } to { background: green; }  }
   @-moz-keyframes bgcolor { from { background: red; } to { background: green; }  }
     @-o-keyframes bgcolor { from { background: red; } to { background: green; }  }
        @keyframes bgcolor { from { background: red; } to { background: green; }  }

<div class="timeline-unit"> Timeline 1 </div>
<div class="timeline-unit"> Timeline 2 </div>
<div class="timeline-unit"> Timeline 3 </div>

但是，如果您需要为每个元素添加边框，有两种选择:

• 使用drop-shadow() filter伪造边界 - Example Here (Webkit/Firefox35+ 支持)。
• 使用CSS transforms为了创建 CSS 形状，所以 border 将不被使用并可供以后使用(IE9+ 也支持)。