.wrapper {
  display: flex;  
  flex-flow: row wrap;
  font-weight: bold;
  text-align: center; 
}

.wrapper > * {
  padding: 10px;
  flex: 1 100%;
}

.header {
  background: deepskyblue;
}
.subheader {
  background: #e5e5e5;
}
.aside-1 {
  background: deepskyblue;
  text-align: left;
}
.main {
  background: #e5e5e5;
}
.aside-2 {
  background: deepskyblue;
  text-align: left;
}

.footer {
  background: #e5e5e5;
}
.price {
  background: deepskyblue;
}
.contact {
  background: #e5e5e5;
}
.photo1 {
  background: deepskyblue;
}
.photo2 {
  background: deepskyblue;
}
.video {
  background: #e5e5e5;
  text-align: center;
}

@media all and (min-width: 600px) {
  .aside { flex: 1 0 0; }
}

@media all and (min-width: 800px) {
  .main    { flex: 3 0px; }
  .aside-1 { flex: 2 0px; }
  .aside-2 { flex: 2 0px; }
  .photo1 { flex: 1 0px; }
  .photo2 { flex: 1 0px; }
}

body {
  padding: 2em; 
}