* {font-family: sans-serif;margin:0;padding:0}
html,body{width:100%;height:100%}

body {
  padding: 0;
}

@media (max-width: 768px) {
  header {
    padding: 1em;
    margin: 0;
  }
}

@media (min-width: 768px) {
  header {
    padding-top: 3em
  }
}

section, article {
  padding: 1em;
}

input[type=text], label {
  display: block;
}

header {
  background-color: #f0f0f0
}

.video {
  padding: 8em;
  text-align: center;
  border: 1px dotted #000;
}

.video:before {
  content: '[video] '
}