example/style.css

html, body {
  background-color: rgb(250, 250, 250);
  font-family: Roboto,"Helvetica Neue",sans-serif;
  font-size: 16px;
  margin: 0;
}

.container {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  height: 100%;
  width: 100%;
}

.main {
  align-items: stretch;
  box-sizing: border-box;
  display: flex;
  flex-direction: row;
  height: 100%;
  margin: 32px;
}

.version {
  color: rgba(0, 0, 0, 0.54);
  margin-right: 16px;
}

.card {
  /* Styled like Material Cards. */
  color: rgba(0, 0, 0, 0.87);
  background-color: white;
  border-radius: 2px;
  box-sizing: border-box;
  box-shadow: 0 1px 3px 0 rgba(0, 0, 0, .2),
              0 1px 1px 0 rgba(0, 0, 0, .14),
              0 2px 1px -1px rgba(0, 0, 0, .12);
  margin: 8px;

  /* Positioned next to each other. */
  display: flex;
  flex: 1 1 50%;
  flex-direction: column;
  max-height: 100%;
  max-width: 50%;
  min-height: 400px;
}

.toolbar {
  /* Styled like Material Toolbar. */
  align-items: center;
  background-color: #22d3c5; /* Taken from webdev.dartlang.org. */
  box-sizing: border-box;
  color: rgba(0, 0, 0, 0.87);
  display: flex;
  font-size: 20px;
  line-height: 1.4;
  margin: 0;
  min-height: 64px;
  padding: 0 16px;
  position: relative;
  width: 100%;
}

.toolbar h2 {
  font-size: inherit;
  font-weight: inherit;
  margin: inherit;
}

.toolbar a:link,
.toolbar a:visited {
  color: rgba(0, 0, 0, 0.87);
}

.toolbar svg {
  fill: currentColor;
}

.card .toolbar {
  border-radius: 3px 3px 0 0;
}

.textarea-container {
  display: flex;
  height: 100%;
  padding: 8px;
}

textarea {
  border-color: rgba(0, 0, 0, 0.12);
  border-width: 0 0 1px;
  box-sizing: border-box;
  color: rgba(0, 0, 0, 0.87);
  font-family: "Roboto Mono",monospace;
  font-size: 100%;
  line-height: 26px;
  overflow: auto;
  padding: 2px 2px 1px;
  width: 100%;
}

textarea:focus {
  border-color: #22d3c5; /* Taken from webdev.dartlang.org. */
  border-width: 0 0 2px;
  outline: 0;
  padding-bottom: 0;
}

#html {
  overflow: auto;
  padding: 8px;
}

footer {
  box-sizing: border-box;
  display: flex;
  font-size: 20px;
  height: 64px;
  padding: 0 16px;
}

footer a:link,
footer a:visited {
  color: rgba(0, 0, 0, 0.87);
}

.radio {
  cursor: pointer;
  display: inline-block;
  margin-right: 16px;
}

i.glyph {
  display: inline-block;
  font-family: 'Material Icons Extended';
  font-size: 16px;
  font-style: normal;
  font-weight: normal;
  line-height: 1;
}

.radio[checked] i.glyph {
  color: #22d3c5;
}

i.glyph.big {
  font-size: 32px;
  height: 32px;
  width: 32px;
}