body{
  background:#0d0d0d;
  color:white;
  font-family:sans-serif;
  text-align:center;
  padding-top:80px;
}
.box{
  background:#1a1a1a;
  padding:30px;
  width:90%;
  max-width:350px;
  margin:auto;
  border-radius:12px;
}
#goBtn{
  width:100%;
  padding:15px;
  font-size:18px;
  margin-top:20px;
  border:none;
  border-radius:8px;
  background:#4CAF50;
  color:white;
  opacity:0.4;
}