How to Get the Width/Height of Any Element in Only CSS
Briefly

Getting the dimension of an element using JavaScript is a trivial task. You barely even need to do anything. But we aren't so lucky in CSS. There are no simple built-in functions for this, so get ready for some slightly hacky experimentation.
Scroll-Driven animations in CSS unlock a lot of possibilities and solve common problems, allowing animation based on a progression along a scroll-based timeline. This can be utilized creatively beyond simple animated effects.
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