You need to refer to the specification and more precisely the painting order to understand when each layer is painted. Without position:relative your element is not positioned and will be painted at the step (4): For all its in-flow, non-positioned, block-level descendants in tree order: If the element is a block, list-item, or other block … Read more
Check if an ancestor element has overflow set (e.g. overflow:hidden); try toggling it. You may have to inspect the DOM tree higher than you expect =). This may affect your position:sticky on a descendant element.
Basics of the CSS z-index property A Simple Concept The z-index property is based on a simple concept: Elements with higher values will sit in front of elements with lower values along the z-axis. So if you apply z-index: 1 to div.box1, and div.box2 has a z-index: 0, then div.box1 will overlay div.box2. In terms … Read more
It’s working fine but you will see nothing. Let’s have a look at the definition: A stickily positioned element is an element whose computed position value is sticky. It’s treated as relatively positioned until its containing block crosses a specified threshold (such as setting top to value other than auto) within its flow root (or … Read more
To correctly understand this, you need to refer to the official specification where you find the equation the element must satisfy: ‘top’ + ‘margin-top’ + ‘border-top-width’ + ‘padding-top’ + ‘height’ + ‘padding-bottom’ + ‘border-bottom-width’ + ‘margin-bottom’ + ‘bottom’ = height of containing block We don’t have any border and padding so in your case it … Read more
This is because the transform creates a new local coordinate system, as per W3C spec: In the HTML namespace, any value other than none for the transform results in the creation of both a stacking context and a containing block. The object acts as a containing block for fixed positioned descendants. This means that fixed … Read more
Short answer: no. (It is now possible with CSS transform. See the edit below) Long answer: The problem with using “fixed” positioning is that it takes the element out of flow. thus it can’t be re-positioned relative to its parent because it’s as if it didn’t have one. If, however, the container is of a … Read more
How to center a “position: absolute” element
How can I center an absolutely positioned element in a div?
There are two important things you need to know: the painting order and the stacking context. If you refer to the specification, you can find how and when elements are painted. Stacking contexts formed by positioned descendants with negative z-indices (excluding 0) in z-index order (most negative first) then tree order. All positioned, opacity or … Read more