* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: #333;
  color: #fff;
  font-family: sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}

.container {
  margin: 50px auto;
  padding: 20px;
  width: 95%;
  max-width: 500px;
  border-radius: 5px;
  background-color: rgba(0, 0, 0, 0.5);
}

h1 {
  margin-bottom: 30px;
  text-align: center;
}

.form-group {
  display: flex;
  flex-direction: column;
}

.form-group + .form-group {
  margin-top: 30px;
}

.form-group:last-child {
  margin-bottom: 20px;
}

.form-control {
  margin: 5px 0 2px;
  padding: 8px 10px;
  width: 100%;
  height: 30px;
  border-radius: 5px;
  border: 0;
}

.form-control:focus,
.btn:focus {
  outline: none;
}

small {
  color: #ffffff99;
}

.btn {
  width: 100%;
  height: 50px;
  margin-top: 30px;
  background-color: rgba(0, 255, 0, 0.3);
  color: #fff;
  font-weight: bold;
  font-family: inherit;
  border: 0;
  border-radius: 5px;
}

.btn:active {
  transform: scale(0.98);
}