如何在伪元素之前添加边框？

Question

下午好，请告诉我。我组成了一个砖块，在砖块的顶部有一个凸角。在整个块上，我有一个用box-shadow制成的角。如何为伪元素（.comment_text:before）精确构建这样的框架

.comment{
  margin-top: 20px;
  padding: 0px 20px 0px 20px;
}
.comment_text{
  max-width: 680px;
  background-color: #f1fbff;
  padding: 10px;
  margin-top: 15px;
  color: #FFF;
  position: relative;
  font-size: 12px;
  line-height: 20px;
  -webkit-box-shadow: 0px 0px 0px 1.5px #cfcfcf;
  -moz-box-shadow: 0px 0px 0px 1.5px #cfcfcf;
  box-shadow: 0px 0px 0px 1.5px #cfcfcf;
  color: #333333;
  font-size: 12pt;
  font-family: Arial, sans-serif;
}
.comment_text:before {
  content: "";
  display: block;
  border-bottom: 15px solid #f2fbff;
  border-right: 20px solid transparent;
  border-left: 0px solid transparent; 
  position: absolute;
  top: -15px;
  left: 22px;
}

<div v-for='comment in comments' class="comment">
  <div class="comment_text">Some Text</div>
</div>

Answer 1

您可以创建另一个psudo元素（:: after）并将其变大。添加类似于您的Div边框的颜色。

    .comment{
    margin-top: 20px;
    padding: 0px 20px 0px 20px;
  }
  .comment_text{
    max-width: 680px;
    background-color: #f1fbff;
    padding: 10px;
    margin-top: 15px;
    color: #FFF;
    position: relative;
    font-size: 12px;
    line-height: 20px;
    -webkit-box-shadow: 0px 0px 0px 1.5px #cfcfcf;
    -moz-box-shadow: 0px 0px 0px 1.5px #cfcfcf;
    box-shadow: 0px 0px 0px 1.5px #cfcfcf;
    color: #333333;
    font-size: 12pt;
    font-family: Arial, sans-serif;
  }
  .comment_text:before {
    content: "";
    display: block;
    border-bottom: 15px solid #cfcfcf;
    border-right: 20px solid transparent;
    border-left: 0px solid transparent; 
    position: absolute;
    top: -15px;
    left: 22px;
  }
  .comment_text:after {
    content: "";
    display: block;
    border-bottom: 18px solid #f2fbff;
    border-right: 20px solid transparent;
    border-left: 0px solid transparent; 
    position: absolute;
    top: -12px;
    left: 24px;
  }

<div v-for='comment in comments' class="comment">
      <div class="comment_text">{{ comment.text }}</div>
    </div>

Answer 2

尝试向其中添加Height和Width。并继续玩直到达到想要的效果。 您还可以添加背景以定义所需的颜色

  .comment_text:before {
    content: "";
    display: block;
    border-bottom: 15px solid #f2fbff;
    border-right: 20px solid transparent;
    border-left: 15px solid transparent; 
    position: absolute;
    top: -15px;
    left: 2px;
    height: 1px;
    width: 10px;
    background: blue;
  }

Answer 3

.comment{
margin-top: 20px;
padding: 0px 20px 0px 20px;
}
.comment_text{
max-width: 680px;
background-color: #f1fbff;
padding: 10px;
margin-top: 15px;
color: #FFF;
position: relative;
font-size: 12px;
line-height: 20px;
-webkit-box-shadow: 0px 0px 0px 1.5px #cfcfcf;
-moz-box-shadow: 0px 0px 0px 1.5px #cfcfcf;
box-shadow: 0px 0px 0px 1.5px #cfcfcf;
color: #333333;
font-size: 12pt;
font-family: Arial, sans-serif;
}
.comment_text:before {
content: "";
display: block;
border-bottom: 15px solid #f2fbff;
border-right: 20px solid transparent;
border-left: 0px solid transparent; 
position: absolute;
top: -15px;
left: 22px;
box-shadow: -2px 0px 0px -0.5px #cfcfcf;  
}    
.comment_text:after {
content: "";
display: block;
width: 23px;
height: 0px;
top: -8px;
left: 20px;
box-shadow: 0px 0px 0px 1px #cfcfcf;
transform: rotate(35deg);
position: absolute;
}