article, aside, details, figcaption, figure, header, hgroup, menu, nav, section {
display: block;
}

body{
 border: solid 0px #FF0000;
  text-align : center;
}



.container {
  font-family: arial;
  font-size: 24px;
  margin: 0 auto;
  width: 600px;
  height: auto;
  outline: dashed 0px black;
}

.child {
  width: 100%;
  height: auto;
  /* 水平方向の中央揃え */
  margin: 0 auto;
}


img {
   border: solid 0px #000000;
   width: 100%;
}