Do not leave space for the element.
Do not leave space for the element. Instead, position it at a specified position relative to its closest positioned ancestor or to the containing block. Absolutely positioned boxes can have margins, they do not collapse with any other margins. --MDN
Do not leave space for the element.
Do not leave space for the element. Instead, position it at a specified position relative to the screen's viewport and doesn't move when scrolled. When printing, position it at that fixed position on every page. --MDN
The inherit CSS keyword causes the element for which it is specified to take the computed value of the property from its parent element.
The inherit CSS keyword causes the element for which it is specified to take the computed value of the property from its parent element. --MDN
https://developer.mozilla.org/en-US/docs/Web/CSS/inherit
The initial CSS keyword applies the initial (or default) value of a property to an element.
The initial CSS keyword applies the initial (or default) value of a property to an element. --MDN
https://developer.mozilla.org/en-US/docs/Web/CSS/initial_value
https://developer.mozilla.org/en-US/docs/Web/CSS/initial
This keyword lays out all elements as though the element were not positioned, and then adjust the element's position, without changing layout (and thus leaving a gap for the element where it would have been had it not been positioned).
This keyword lays out all elements as though the element were not positioned, and then adjust the element's position, without changing layout (and thus leaving a gap for the element where it would have been had it not been positioned). The effect of position:relative on table-*-group, table-row, table-column, table-cell, and table-caption elements is undefined. --MDN
The revert CSS keyword reverts the cascaded value of the property from its current value to the value the property would have had if no changes had been made by the current style origin to the current element.
The revert CSS keyword reverts the cascaded value of the property from its current value to the value the property would have had if no changes had been made by the current style origin to the current element. --MDN
https://developer.mozilla.org/en-US/docs/Glossary/Style_origin
https://developer.mozilla.org/en-US/docs/Web/CSS/revert
This keyword let the element use the normal behavior, that is it is laid out in its current position in the flow.
This keyword let the element use the normal behavior, that is it is laid out in its current position in the flow. The top, right, bottom, and left properties do not apply. --MDN
The unset CSS keyword resets a property to its inherited value if the property naturally inherits from its parent, and to its initial value if not.
The unset CSS keyword resets a property to its inherited value if the property naturally inherits from its parent, and to its initial value if not. In other words, it behaves like the inherit keyword in the first case, when the property is an inherited property, and like the initial keyword in the second case, when the property is a non-inherited property. --MDN
https://developer.mozilla.org/en-US/docs/Web/CSS/unset
(Since version ) see corresponding Javadoc for more information.
https://developer.mozilla.org/en-US/docs/Web/CSS/position