style.css

body{
  background-color: #222;
  margin: 0;
  position: relative;
  width: 100%;
  height: 100%;
}

div.header {
  font-family: 'Open Sans', sans-serif;
  padding-left: 0;
  text-align: center;
  vertical-align: middle;
  font-weight: bolder;
  font-size: 4vh;
  color: white;
  background-color: #42484a;
  height: 50px;
  line-height: 50px;
  width: 100%;
}

div.terminal {
  position: absolute;
  font-size: 2vh;
  width: 100%;
  height: calc(100% - 50px);
  background-color: #222;
}

div.footer {
  font-family: 'Teko', sans-serif;
  padding: 0;
  position: absolute;
  display: flex;
  bottom: 0;
  text-align: center;
  vertical-align: middle;
  font-weight: bold;
  font-size: 4vh;
  color: white;
  background-color: #42484a;
  height: 50px;
  line-height: 50px;
  width: 100%;
}

div.inputfield {
  text-align: left;
  width: calc(100% - 150px);
  background-color: inherit;
  height: inherit;
}

div.button {
  text-align: center;
  height: 50px;
  width: 50px;
}

button {
  text-align: center;
  height: inherit;
  width: inherit;
  background-color: inherit;
  border: none;
  color: white;
}

textarea.terminal {
  position: absolute;
  color: white;
  width: inherit;
  height: inherit;
  background-color: inherit;
  resize: none;
  border: none;
}

input.input {
  font-family: 'Open Sans', sans-serif;
  color: white;
  font-size: 3vh;
  position: absolute;
  line-height: 50px;
  width: inherit;
  height: inherit;
  background-color: inherit;
  resize: none;
  border: none;
  white-space: nowrap;
  overflow-x: scroll;
}