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  <div class="one_area">
    <div class="one_box">
    <div class="one_box">
      <p>ここは透過指定<br><br>※ IE11で確認したところ、透過ではなくブルーになっていた。原因は、backgroundの色指定がrgbになっていた。<br><br>この場合の対応方法<br>rgb → rgba<br><br>なるほどなるほど。<br>と言いつつ最近はIEはスルーでオッケーになってきているのですが。<br>備忘録。</p>
    <div class="one_box">

  <p class="_a"><a href="" target="_blank" class="link">View the note</a></p>


                .one_area {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
.one_area .one_box {
  width: 33.333%;
  background: #03a9f4;
.one_area .one_box:nth-child(2) {
  background: rgba(255, 255, 255, 0);/*IE11*/
  background: rgb(255 255 255 / 0%);
.one_area .one_box p {
  text-align: center;
  padding: 30px 15px;


body {
  font-family: YuGothic, "游ゴシック体", "Yu Gothic", "ヒラギノ角ゴ Pro", "Hiragino Kaku Gothic Pro", "メイリオ", Meiryo, "MS Pゴシック", "MS PGothic", sans-serif;
  font-size: 14px;
  letter-spacing: .025em;
  line-height: 1.8;
  background: #ffeb3b;
section {
  max-width: 800px;
  margin: 0 auto;
  padding: 50px 20px;
section p._a {
  font-size: 12px;
  font-weight: bold;
  margin: 30px 0 0;
section p._a .link {
  display: inline-block;
  color: #607D8B;
  padding-left: 1.3em;
  text-indent: -1.3em;
section p._a .link:before {
  content: '';
  display: inline-block;
  width: 5px;
  height: 5px;
  border-top: 2px solid #607D8B;
  border-right: 2px solid #607D8B;
  -webkit-transform: rotate(45deg);
  transform: rotate(45deg);
  margin-right: 10px;