html,
body {
  background: #000 url("HD_wave_wallpaper_by_NeonSalad.jpg") no-repeat 50% 0% fixed;
  color: #eee;
  font: 12px Helvetica, Arial, sans-serif;
}
h1 {
  position: absolute;
  top: 50px;
  left: 50%;
  margin-left: -100px;
  width: 400px;
  height: 300px;
  font-weight: bold;
  text-align: center;
}
form {
  position: absolute;
  top: 50px;
  left: 50%;
  margin-left: -100px;
  margin-top: 70px;
  width: 380px;
  height: 300px;
  background: rgba(0,0,0,0.6);
  border-radius: 20px;
  border: solid 5px rgba(255,255,255,0.85);
  font-weight: bold;
  text-align: center;
  padding: 0 20px;
}
form::before {
  display: block;
  position: absolute;
  top: 0;
  left: -400px;
  top: -70px;
  width: 367px;
  height: 489px;
  background: url("plonk.png") no-repeat 0 50%;
  content: '';
}
label {
  width: 100px;
  text-align: right;
  display: block;
  float: left;
  clear: both;
  padding: 6px 5px;
  margin-top: 10px;
}
input {
  margin-top: 10px;
  background: #333;
  border: solid 2px #fff;
  border-radius: 5px;
  color: #fff;
  font-weight: bold;
  padding: 3px 5px;
}
button {
  margin: 10px 0;
  background: #333;
  border: solid 2px #fff;
  border-radius: 5px;
  color: #fff;
  font-weight: bold;
  padding: 5px 20px;
}
button:hover {
  background: #666;
}
a {
  color: #ccc;
}
a:hover {
  color: #fff;
}