Home > Article > Web Front-end > CSS uses :before :after to write small triangle examples to share
This article mainly introduces the detailed information on how to use :before :after to write small triangles in CSS. The editor thinks it is quite good, so I will share it with you now and give it as a reference. Let’s follow the editor to take a look, I hope it can help everyone.
The triangles written before are always in the same color and have no border style. As follows:
The CSS code is as follows:
.tri-up{width: 0;height:0;border-left:20px solid transparent;border-right: 20px solid transparent;border-bottom: 20px solid red; } .tri-left{width: 0;height:0;border-top:20px solid transparent;border-bottom: 20px solid transparent;border-left: 20px solid red;} .tri-right{width: 0;height:0;border-top:20px solid transparent;border-bottom: 20px solid transparent;border-right: 20px solid red;} .tri-down{width: 0;height:0;border-left:20px solid transparent;border-right: 20px solid transparent;border-top: 20px solid red; }
To write the following small triangle, you need to use pseudo Class:before :after
CSS code:
#demo { margin: 100px;; width: 100px; height: 100px; background-color: #fff; position: relative; border: 2px solid #333; } //方框的样式 #demo:after, #demo:before { border: solid transparent; content: ' '; height: 0; left: 100%; //根据三角形的位置,可以随意更改。 position: absolute; width: 0; } #demo:after { border-width: 10px; border-left-color: #fff; top: 20px;//根据三角的位置改变 }//此处是一个白色的三角 #demo:before { border-width: 12px; border-left-color: #000; top: 18px; }此处是一个黑色的三角 //当#demo:after和#demo:before的样式重合以后,由于top值的大小不同,就可以得到中间是白色,但是边框的三角形。如上图。
<p id="demo"></p>
If To change to the style of the picture below:
The CSS code is as follows:
#demo { margin: 100px;; width: 100px; height: 100px; background-color: #fff; position: relative; border: 2px solid #333; } #demo:after, #demo:before { border: solid transparent; content: ' '; height: 0; top: 100%; position: absolute; width: 0; } #demo:after { border-width: 10px; border-top-color: #fff; left: 20px; } #demo:before { border-width: 12px; border-top-color: #000; left: 18px; }
Related recommendations:
How to use CSS to achieve the small triangle effect_html/css_WEB-ITnose
Use CSS3 to implement a div box with a small triangle (without pictures)_html/css_WEB-ITnose
The above is the detailed content of CSS uses :before :after to write small triangle examples to share. For more information, please follow other related articles on the PHP Chinese website!