:root {
  --bg: #0a0a0b;
  --surface: #141416;
  --border: #262629;
  --text: #f5f5f5;
  --text-dim: #9a9aa2;
  --accent: #7c5cff;
  --accent-text: #ffffff;
  --error: #ff6b6b;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px 16px;
  line-height: 1.4;
}

.card {
  width: 100%;
  max-width: 420px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px 22px;
}

h1 {
  font-size: 1.4rem;
  margin: 0 0 8px;
}

.subtitle {
  color: var(--text-dim);
  font-size: 0.95rem;
  margin: 0 0 20px;
}

.field {
  margin-bottom: 16px;
}

label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 6px;
}

input[type="text"] {
  width: 100%;
  font-size: 16px;
  padding: 12px 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  outline: none;
  transition: border-color 0.15s ease;
}

input[type="text"]:focus {
  border-color: var(--accent);
}

input[type="text"].invalid {
  border-color: var(--error);
}

.field-hint {
  color: var(--text-dim);
  font-size: 0.78rem;
  margin: 6px 0 0;
  line-height: 1.35;
}

.field-error, .form-error {
  min-height: 1.1em;
  color: var(--error);
  font-size: 0.82rem;
  margin: 6px 0 0;
}

.form-error:empty, .field-error:empty {
  margin: 0;
}

button {
  width: 100%;
  font-size: 1rem;
  font-weight: 600;
  padding: 14px 16px;
  border: none;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-text);
  cursor: pointer;
  transition: opacity 0.15s ease, transform 0.1s ease;
}

button:active {
  transform: scale(0.98);
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

#copy-btn {
  margin-top: 18px;
}

#your-code {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-align: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 12px;
  margin: 12px 0;
  word-break: break-all;
}

.instructions {
  color: var(--text-dim);
  font-size: 0.9rem;
  margin-top: 18px;
}

#success-view {
  animation: fade-in 0.2s ease;
}

@keyframes fade-in {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 360px) {
  .card {
    padding: 22px 16px;
  }
  #your-code {
    font-size: 1.8rem;
  }
}