body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f8fafc;
  color: #0f172a;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}
.container {
  text-align: center;
  max-width: 600px;
  width: 100%;
  padding: 40px;
  background: #ffffff;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}
h1 {
  font-size: 42px;
  margin-bottom: 10px;
}
p {
  font-size: 18px;
  color: #475569;
  margin-bottom: 20px;
}
.price {
  font-size: 28px;
  margin-bottom: 20px;
  color: #16a34a;
}
form {
  margin-top: 20px;
  text-align: left;
}
.form-group {
  margin-bottom: 15px;
}
label {
  display: block;
  font-size: 14px;
  margin-bottom: 5px;
}
input {
  width: 100%;
  padding: 12px;
  font-size: 16px;
  border: 1px solid #cbd5f5;
  border-radius: 8px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}
input:focus {
  border-color: #2563eb;
}
input.invalid {
  border-color: #dc2626;
  box-shadow: 0 0 0 2px rgba(220,38,38,0.1);
}
.error {
  color: #dc2626;
  font-size: 12px;
  margin-top: 4px;
  display: none;
}
.btn {
  width: 100%;
  padding: 14px;
  font-size: 18px;
  color: #ffffff;
  background: #94a3b8;
  border: none;
  border-radius: 8px;
  cursor: not-allowed;
  transition: 0.3s;
}
.btn.enabled {
  background: #2563eb;
  cursor: pointer;
}
.btn.enabled:hover {
  background: #1d4ed8;
}
.contact {
  margin-top: 20px;
  font-size: 14px;
  color: #64748b;
  text-align: left;
}