* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background-color: #cfe9ff;
  color: #123456;
}

.app-container {
  max-width: 480px;
  margin: 0 auto;
  padding: 16px;
}

.app-header {
  text-align: center;
  margin-bottom: 16px;
}

.app-header h1 {
  font-family: "Chewy", system-ui, sans-serif;
  font-size: 2.2rem;
  margin: 8px 0 0;
  color: #123456;
}

.subtitle {
  margin: 4px 0 12px;
  font-size: 0.95rem;
  color: #345678;
}

.label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
  color: #234567;
}

.input-section,
.output-section {
  margin-bottom: 16px;
}

.text-input {
  width: 100%;
  padding: 10px 12px;
  font-size: 1rem;
  border-radius: 10px;
  border: 1px solid #9bbfe5;
  background-color: #ffffff;
  color: #123456;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
}

.text-input:focus {
  outline: none;
  border-color: #5a8fdc;
  box-shadow: 0 0 0 2px rgba(90, 143, 220, 0.3);
}

.output-area {
  width: 100%;
  padding: 10px 12px;
  font-size: 1rem;
  border-radius: 10px;
  border: 1px solid #9bbfe5;
  background-color: #ffffff;
  color: #123456;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
  resize: vertical;
}

.primary-button {
  margin-top: 10px;
  width: 100%;
  padding: 10px 12px;
  font-size: 1rem;
  border-radius: 999px;
  border: none;
  background-color: #5a8fdc;
  color: #ffffff;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 3px 6px rgba(0, 0, 0, 0.15);
  touch-action: manipulation;
}

.primary-button:active {
  background-color: #4a7ac0;
  transform: translateY(1px);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
}

.buy-text {
  text-align: center;
  font-size: 1rem;
  color: #234567;
  margin: 20px 0 10px;
  font-weight: 600;
}

.book-cover-bottom {
  display: block;
  margin: 20px auto;
  width: 320px;
  border-radius: 12px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

@media (max-width: 400px) {
  .app-container { padding: 12px; }
  .app-header h1 { font-size: 1.9rem; }
}