html,
body {
  width: 100vw;
  height: 100vh;
  margin: 0;
  border: 0;
  padding: 0;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  font-family: Arial, Helvetica, lucida, sans-serif;
}

*,
*::before,
*::after {
  -webkit-box-sizing: inherit;
  -moz-box-sizing: inherit;
  box-sizing: inherit;
}


.intro {position:absolute;top:50px; text-align:center;width:100%; font-size:2em; color:#fff;}

#wrapper {
  width: 100%;
  height: 100%;
  background: #212121;

  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.doors {
  display: flex;
}

.door {
  background: #CCC;
  box-shadow: 0 0 3px 2px rgba(0, 0, 0, 0.4) inset;
  width: 200px;
  height: 300px;
  overflow: hidden;
  border-radius: 1ex;
  margin: 1ch;
}

.boxes {
  transition: transform 1s ease-in-out;
}

.box {
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 3rem;
}

.buttons {
  margin: 3rem 0 2rem 0;
}
/*
button {
  cursor: pointer;
  font-size: 1.2rem;
  text-transform: uppercase;
  margin: 0 0.2rem 0 0.2rem;
}
*/
.info {
  position: fixed;
  bottom: 0;
  width: 100%;
  text-align: center;
}



.btn {
background-color: #03F;
border: none;
color: white;
padding: 14px 28px;
text-align: center;
font-size: 16px;
border-radius: 8px;
cursor: pointer;
transition: background-color 0.3s, transform 0.2s;

width:200px; height:100px;margin:30px;font-size:2em;
}

.btn:hover {
background-color: #009;
transform: translateY(-2px);
}

.btn:active {
transform: translateY(0);
}