HTML {
  display: flex;
  height: 100%;
  font-size: 16px;
}

BODY {
  width: 100%;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  font: 14px/1.4 Arial, sans-serif;
  color: #222;
}

A {
  color: inherit;
}
A:hover {
  text-decoration: none;
}

.textarea,
.iframe {
  width: 100%;
  flex-grow: 1;
  box-sizing: border-box;
  border: none;
}

.controls {
  width: 100%;
  flex-basis: 2.5em;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  box-sizing: border-box;
  border: 1px solid rgba(0,0,0,.25);
  background: #EEE;
}

.control {
  position: relative;
  min-height: 1.5rem;
  margin-left: 10px;
  padding: 0 1rem;
  background: #EEE;
  border: 2px solid rgba(0,0,0,.25);
  border-radius: .5em;
  outline: none;
  font: inherit;
  line-height: 1em;
  text-transform: uppercase;
  cursor: pointer;
  color: rgba(0,0,0,.6);
}

.control:focus::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  border-radius: inherit;
  box-shadow: 0 0 0 3px rgba(0,0,0,.2);
  pointer-events: none;
}

.control--pressed {
  background-color: yellowgreen;
  background-origin: border-box;
  background-image: linear-gradient(transparent, greenyellow);
  color: rgba(0,0,0,.9);
}

.link {
  margin-right: 10px;
}

.link--direct {
  margin-left: auto;
}

@media (max-width: 400px) {
  .link SPAN {
    display: none;
  }
}

.columns {
  flex-grow: 1;
  display: flex;
}

.column {
  flex-basis: 33%;
  flex-grow: 1;
  display: flex;
  box-sizing: border-box;
  border: 1px solid rgba(0,0,0,.25);
}

.column--collapsed {
  display: none;
}

.textarea {
  padding: 10px;
  font: inherit;
  color: inherit;
}

.textarea:focus {
  outline: 2px solid yellowgreen;
}