Position Absolute Not Scrolling Properly - html

Question

I'm trying to create an area that contains all my absolutely positioned items. It works great until its sibling has an overflow attached to it. In the example below, when you start scrolling, the child div scrolls as if it's fixed. If you comment out the overflow: auto in the #app CSS, you'll get the desired behavior, but obviously the layout is incorrect. How can I fix this issue without moving the absolute div into the #app div?
#app {
height: 200px;
/* If I take this off, I get the desired behavior */
overflow: auto;
}
.content {
height: 300px;
width: 100%;
color: white;
background-color: darkblue;
}
.absolute {
position: absolute;
top: 0;
left: 0;
}
.child {
top: 20px;
height: 20px;
position: absolute;
background-color: white;
width: 300px;
}
body, html {
height: 100%;
width: 100%;
margin: 0;
padding: 0;
}
<div id="app">
<div class="content">
Content 1
</div>
</div>
<div class="absolute">
<div class="child">
Shouldn't be fixed when scrolling
</div>
</div>

Answer 1

If you want to use absolute positioning on .absolute you'll have to nest that code within #app and set it to position: relative;. The absolute positioning is referring to its nearest positioned ancestor, in this case, the body element, hence, why it is staying fixed. So you'll have to set #app to relative and it should work just fine.
#app {
height: 200px;
/* If I take this off, I get the desired behavior */
overflow: auto;
position: relative;
}
.content {
height: 300px;
width: 100%;
color: white;
background-color: darkblue;
}
.absolute {
position: absolute;
top: 0;
left: 0;
}
.child {
top: 20px;
height: 20px;
position: absolute;
background-color: white;
width: 300px;
}
body,
html {
height: 100%;
width: 100%;
margin: 0;
padding: 0;
}
<div id="app">
<div class="content">
Content 1
</div>
<div class="absolute">
<div class="child">
Shouldn't be fixed when scrolling
</div>
</div>
</div>
This should also work for you, see changes I made to HTML and CSS below.
#app {
height: 200px;
/* If I take this off, I get the desired behavior */
overflow: auto;
}
.content {
height: 300px;
width: 100%;
color: white;
background-color: darkblue;
}
.absolute {
position: relative;
top: 0;
left: 0;
}
.child {
top: 0px;
height: 20px;
position: absolute;
background-color: white;
width: 300px;
color: black;
}
body,
html {
height: 100%;
width: 100%;
margin: 0;
padding: 0;
}
<div id="app">
<div class="content">Content 1
<div class="absolute">
<div class="child">
Shouldn't be fixed when scrolling
</div>
</div>
</div>
</div>