body {
  max-width: 500px;
}
#content-area {
  width: 100%;
  display: grid;
  grid-template-columns: 600px 300px;
  grid-gap: 50px;
}
@media screen and (max-width: 949px) {
  #content-area {
    display: block;
  }
}
#main-area {
  width: 100%;
  user-select: none;
}

#iframe {
  margin-bottom: 24px;
  margin: 0 auto;
}
.explain p {
  font-size: 0.8rem;
}
@media screen and (max-width: 949px) {
  .explain {
    padding: 0 8px;
  }
}
.explain li {
  font-size: 0.8rem;
  list-style-position: inside;
  list-style-type: circle;
}
#side {
  margin-bottom: 24px;
}
#footer {
  width: 950px;
}

@media screen and (max-width:950px) {
  #footer {
    width: 600px;
  }
  #side {
    width: 100%;
    padding: 0 8px;
    margin-top: 24px;
  }
}