body {
  font-family: Arial;
  background: #0f172a;
  color: white;
  text-align: center;
}

header {
  display: flex;
  justify-content: space-between;
  padding: 20px;
}

a { color: #60a5fa; text-decoration: none; }

.btn {
  background: #6366f1;
  padding: 10px 20px;
  border-radius: 6px;
  color: white;
}

.big { font-size: 20px; }

input, textarea {
  display: block;
  margin: 10px auto;
  padding: 10px;
  width: 280px;
}