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                <!DOCTYPE html>
<html lang="ja">

  <meta charset="UTF-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />

  <span class="a">自動で改行されることはありません、</span>
  <span class="b">bodyタグの横幅いっぱいまで来ると自動で折り返されます。</span>
  <span class="c">横幅と高さの設定は出来ません。</span>
  <span class="d">改行する時は<br>brタグを使います。</span>



                body {
  width: 400px;
  background-color: lightgray;
span {
  background-color: lightblue;
.a {
  background-color: orange;
.b {
  background-color: magenta;
.c {
  background-color: yellowgreen;
  width: 200px;
  height: 75px;
.d {