index.css

html,
body,
p {
  margin: 0;
}

html,
body,
main {
  height: 100%;
}

body {
  position: relative;
  background-color: #ddd;
  /*font-family: Consolas, 'Source Sans Pro', 'Helvetica Neue', Arial, sans-serif;*/
  font-family: Menlo, Monaco, Lucida Console, Liberation Mono, DejaVu Sans Mono,
    Bitstream Vera Sans Mono, Courier New, monospace, serif;
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

main {
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 13px;
}

.sh {
  width: 50%;
  min-width: 400px;
  height: 300px;

  padding: 10px;
  box-sizing: border-box;
  box-shadow: 1px 2px 5px 0px rgba(0, 0, 0, 0.1);
  border-radius: 2px;
}

.sh-dark {
  background-color: black;
  color: #fff;
}

.sh-hd {
  height: 30px;
  position: relative;
}

.sh-icon {
  display: inline-block;
  height: 12px;
  width: 12px;
  border-radius: 50%;
  position: absolute;
  top: 0;
  bottom: 0;
  margin: auto;
  text-align: center;
  line-height: 12px;
  cursor: pointer;
}

.sh-icon:hover {
  color: rgba(0, 0, 0, .6);
}

.sh-icon-close {
  background-color: #ff5f56;
  color: #ff5f56;
  left: 10px;
}

.sh-icon-minimize {
  background-color: #ffbd2e;
  left: 30px;
}

.sh-icon-full-screen {
  background-color: #27c93f;
  left: 50px;
}

.sh-bd {
  padding: 10px;
  font-family: Menlo, Monaco, Lucida Console, Liberation Mono, DejaVu Sans Mono,
    Bitstream Vera Sans Mono, Courier New, monospace, serif;
}

.line {
  line-height: 1.5;
}

.result {
  color: #67a61c;
}