#main_contents{
width:650px;
}
#side_contents{
width:250px;
}

.page h3{
padding:8px;
background-color:#EDEFFB;
border-top:1px solid #444;
border-bottom:1px solid #555;
}

#side_contents h3{
margin-top:17px !important;
color:#ffffff;
background-color:#DC0958;
background-image:none;
margin-top:0px;
padding-left:10px;
border-radius:0px;
margin-left:0px;
font-size:1.1em;
}
.youtube {
  width: 100%;
  aspect-ratio: 16 / 9;
}
.youtube iframe {
  width: 100%;
  height: 100%;
}
@media only screen and (max-width: 640px) { 
#main_contents{
width:100%;
}
##main_contents h2{
width:94%;
}
#side_contents{
width:100%;
}

}