1.flex layout structure of a sub-element FFC This enables declaration margin: auto automatically calculated when the available space horizontally and vertically at equal and are laid out around this sub-element may be used to simplify the just-content: center; align- item : center wording ordered such that element is centered with reference to the wording more useful https://www.cnblogs.com/coco1s/p/10910588.html
2.transform: translate (50%; 50%) will occur because the font is fuzzy because transform reference is the size of the element itself will change the font blurring when the element size to the element size when a non-integer