style.css

/* mobile version*/
@media (max-width:530px){
  html * { font-size: 1em; }
  input { width: 100%; }
  #map {
    width: 100%;
    height: 60%;
    height: -webkit-calc(100% - 275px);
    height: -moz-calc(100% - 275px);
    height: calc(100% - 275px);
    margin: 20px 0px;
  }

  .inputText {
    text-align: center;
  }

  button {
    padding: 10px;
    margin: 10px 0px;
  }
}

/* desktop version*/
@media (min-width:530px){
  #map {
    width: 100%;
    height: 60%;
    height: -webkit-calc(100% - 154px);
    height: -moz-calc(100% - 154px);
    height: calc(100% - 154px);
    margin: 20px 0px;
  }

  .inputText {
    display: inline-block;
  }

  button {
    padding: 5px;
    margin: 0px 0px;
  }
}

html,body {
    height:100%;
    padding:0;
    margin:0;
}

body {
  padding: 0px 10px;
}

h1 {
  margin: 0px;
  padding: 6px;
}

input {
  text-align: center;
}

footer {
  bottom: 10px;
  position: absolute;
}

button {
  border-radius: 10px;
  background: linear-gradient(whitesmoke,lightgray);
  border: 1px solid gray;
  color: black;
  cursor: pointer;
}

button:hover {
  background: linear-gradient(lightgray,whitesmoke);
}