body {
  overflow: hidden;
}

main {
  position: fixed;
  inset: 50%;
  transform: translate(-50%, -50%)
}

div {
  float: left;
}

input {
  position: fixed;
  inset: 40% 50%;
  z-index: 10;
  transform: translate(-50%, -50%);
  width: 350px;
  max-width: 90%;
  height: 30px;
  padding: 5px 10px;
  border: 0;
  border-radius: 6px;
  opacity: 0.7;
  transition: opacity 0.5s;
}

input:hover,
input:focus {
  opacity: 1;  
}

a {
  color: white;
}