body {
  margin: 3%;
}
/* -- css -- */

header{
 max-width: 1200px;
 background: #ff838b;
}
.contentsA{background: #b3d874;}
.contentsB{background: #f0fefa;}
footer{
 max-width: 1200px;
 background: #ffce5b;
}

.contentsA{
  width: 300px;
/*  height: 100px;*/
}
.contentsB{
  width: 900px;
/*  height: 100px;*/
}

.resizeimage {
   max-width: 800px;  /*�ő啝 */
   min-width: 240px; /* �ŏ��� */

}
.resizeimage img { width: 100%; height: auto;}


.main{
display: flex;
}