In 2021 appeared a new CSS trick which is called the flexbox gap. This property is borrowed from Grid CSS and is called grid-gap. The gap is used to create space between cells.
Devon Govett on X: Made a 10 line polyfill for flexbox gap
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Shripal Soni on X: CSS Tip 🤩 A better and easier way to add gap
Problem with gap property in flexbox : r/css
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