body{
  margin:0;
  max-width:1920px;
  margin:0px auto;
  display:flex;
  flex-direction: column;
  min-height:100vh;
}
header{

}
main{
  flex: 1;
}
.wrapper{
  max-width:1200px;
  margin:0px auto;
}
.row {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
}
.column {
  flex: 1;
}
.quarter{
  flex:0.25;
}
.third{
  flex:0.33;
}
.half{
  flex:0.5;
}
.twothirds{
  flex:0.66;
}
.threequarters{
  flex:0.75;
}
.minimal{
  flex:0.0;
}
.column,.quarter,.third,.half,.twothirds,.threequarters,.minimal{
  padding:8px;
}

@media (max-width: 639px) {
  main .row {
    flex-direction: column;
  }
  .reverse{
    flex-direction:column-reverse;
  }

}