html {
  overflow: hidden;
  background: #EEE;
  font-size: 2em;
  font-family: sans-serif;
}
body {
  margin: 0;
  height: 60dvh;
  overflow: hidden;
}
input,
button,
select {
  font: inherit;
}
.app {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  height: 100%;
}
.app input {
  width: 80%;
  padding: 1em 1em;
  border: none;
  text-align: center;
  appearance: none;
  background: none;
  border-bottom: 2px solid #333;
  border-radius: 0;
  outline: none;
}
.app button {
  border: 0;
  background: none;
  margin-top: 20px;
  padding: 1em;
}
.app select {
  margin-top: 20px;
  display: none;
}