How to position a CSS triangle using ::after?

Question

I've created a div with a bottom arrow using ::after. Here is the HTML code:

<div class="sidebar-resources-categories">Topics</div> <div class="text-content">ok ok</div> 

And here is the CSS:

.sidebar-resources-categories{     height: 50px;     margin-bottom: 20px;     background-color: #e8e8e8;     font-weight: 600;     line-height: 50px;     text-align: center;     font-size: 20px; } .sidebar-resources-categories::after{     content: '';     position: absolute;     left: 42%;     top: 100%;     width: 0;     height: 0;     border-left: 20px solid transparent;     border-right: 20px solid transparent;     border-top: 20px solid #e8e8e8;     clear: both; } 

Here is the result:

I would like the arrow to be at the very bottom of the grey div. I don't want to have the content between the div and the bottom arrow. Do you know how I can do that?

Answer 1

Just add position:relative to the parent element .sidebar-resources-categories

http://jsfiddle.net/matthewabrman/5msuY/

explanation: the ::after elements position is based off of it's parent, in your example you probably had a parent element of the .sidebar-res... which had a set height, therefore it rendered just below it. Adding position relative to the .sidebar-res... makes the after elements move to 100% of it's parent which now becomes the .sidebar-res... because it's position is set to relative. I'm not sure how to explain it but it's expected behaviour.

read more on the subject: http://css-tricks.com/absolute-positioning-inside-relative-positioning/

Answer 2

Add a class:

.com_box:after {      content: '';     position: absolute;     left: 18px;     top: 50px;     width: 0;     height: 0;     border-left: 20px solid transparent;     border-right: 20px solid transparent;     border-top: 20px solid #000;     clear: both;  } 

Updated your jsfiddle: http://jsfiddle.net/wrm4y8k6/8/