I disagree. Check the changes required to the spacing/sizing. Soon you will need to adjust those values and that.is.maintenance. Multiply this by each detail and soon you have more work than you signed up for. This is usually when someone comes along and wants a rewrite because the codebase is fragile.
If you're using a CSS preprocessor like SCSS or LESS you can just define the height for the toolbar as a variable and then use the mask area for the blur as a multiplier (eg. 1.88) of that variable. In general for making things easy.to.maintain it's better to not build project-wide stylesheets with raw CSS.
It's not universally safe to use CSS nesting yet. Without nesting support, writing raw CSS is like raw-dogging a sex-trafficked Vietnamese prostitute from Malaysia. Sure, it will probably work, but if your goal is zero maintenance then you're ignoring the post-exposure prophylaxsis and antibiotic regimens necessary for typical usage patterns.
I disagree. Check the changes required to the spacing/sizing. Soon you will need to adjust those values and that.is.maintenance. Multiply this by each detail and soon you have more work than you signed up for. This is usually when someone comes along and wants a rewrite because the codebase is fragile.