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  %p CSS is awesome!



                // [CSS]要素を天地左右の中央に配置、最近主流になっている実装方法のまとめ | コリス

body {
  // ## Using Flex Box
  // display: flex;
  // justify-content: center;
  // align-items: center;
  // min-height: 100vh;
  // ## /Using Flex Box
  // ## Using CSS Grid
  display: grid;
  grid-template-columns: 100vw;
  grid-template-rows: 100vh;
  // ## /Using CSS Grid
  background: #3397FF;
  line-height: 1.5em;

main {
  // ## Using Position property
  // position: absolute;
  // top: 50%;
  // left: 50%;
  // transform: translate(-50%, -50%);
  // ## /Using Position property

  // ## Using Viewport units: vh
  // margin: 50vh auto 0;
  // transform: translateY(-50%);
  // ## /Using Viewport units: vh
  // ## Using CSS Grid
  justify-self: center;
  align-self: center;
  // ## /Using CSS Grid
  padding: 15px 30px;
  background: rgba(0,0,0,0.4);
  color: #fff;
  text-align: center;
  width: 300px;