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

body {
  background: #1a1a1a;
  color: #e8e8e8;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 20px;
}

.container {
  max-width: 460px;
  width: 100%;
}

.lang-switch {
  text-align: center;
  margin-bottom: 20px;
  font-size: 13px;
  letter-spacing: 0.5px;
}

.lang-switch a {
  color: #666;
  text-decoration: none;
  transition: color 0.15s;
}

.lang-switch a:hover {
  color: #aaa;
}

.lang-switch a.active {
  color: #f5f0e8;
  font-weight: 600;
}

.lang-switch span {
  color: #333;
  margin: 0 8px;
}

.header {
  text-align: center;
  margin-bottom: 28px;
}

.header h1 {
  font-size: 28px;
  font-weight: 800;
  color: #f5f0e8;
  letter-spacing: -0.5px;
}

.tagline {
  font-size: 13px;
  color: #777;
  margin-top: 6px;
}

.input-section {
  margin-bottom: 20px;
}

textarea {
  width: 100%;
  min-height: 110px;
  padding: 14px;
  background: #222;
  border: 1px solid #383838;
  border-radius: 8px;
  color: #e8e8e8;
  font-size: 14px;
  font-family: inherit;
  resize: vertical;
  transition: border-color 0.15s;
  line-height: 1.5;
}

textarea:focus {
  outline: none;
  border-color: #555;
}

textarea::placeholder {
  color: #555;
}

button {
  width: 100%;
  padding: 13px;
  margin-top: 10px;
  background: #f5f0e8;
  color: #1a1a1a;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s;
}

button:hover {
  background: #fff;
}

button:active {
  background: #e0dbd3;
}

.loading {
  text-align: center;
  padding: 24px;
  color: #666;
  font-size: 13px;
}

.loading p {
  animation: pulse 1.2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.result-section {
  margin-bottom: 20px;
}

#receiptContainer {
  display: flex;
  justify-content: center;
  overflow-x: auto;
}

#receiptContainer svg {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  box-shadow: 0 8px 30px rgba(0,0,0,0.4);
}

.receipt-info {
  text-align: center;
  margin-top: 8px;
  font-size: 11px;
  color: #555;
  font-family: 'SF Mono', 'Fira Code', 'Courier New', monospace;
}

.actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}

.actions button {
  flex: 1;
  padding: 10px;
  font-size: 13px;
  font-weight: 500;
  background: #2a2a2a;
  color: #ccc;
  border: 1px solid #3a3a3a;
  border-radius: 6px;
}

.actions button:hover {
  background: #333;
  border-color: #555;
}

.upgrade-section {
  margin-top: 20px;
}

.upgrade-card {
  background: #1e1e1e;
  border: 1px solid #333;
  border-radius: 10px;
  padding: 18px;
}

.upgrade-card h3 {
  font-size: 15px;
  color: #f5f0e8;
  margin-bottom: 6px;
}

.upgrade-card p {
  font-size: 12px;
  color: #888;
  line-height: 1.6;
  margin-bottom: 10px;
}

.payment-info {
  margin-top: 12px;
  font-size: 12px;
  color: #bbb;
}

.wallet-box {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 8px 0;
  background: #181818;
  padding: 10px 12px;
  border-radius: 6px;
  border: 1px solid #2a2a2a;
}

.wallet-box code {
  font-size: 10px;
  color: #999;
  word-break: break-all;
  flex: 1;
  font-family: 'SF Mono', 'Fira Code', 'Courier New', monospace;
}

.wallet-box button {
  width: auto;
  padding: 5px 10px;
  margin: 0;
  font-size: 11px;
  background: #3a3a3a;
  color: #ddd;
  border: none;
  border-radius: 4px;
  white-space: nowrap;
}

.wallet-box button:hover {
  background: #4a4a4a;
}

.payment-note {
  font-size: 11px !important;
  color: #666 !important;
  margin-top: 6px;
}

.verify-btn {
  width: 100%;
  padding: 10px;
  margin-top: 6px;
  background: #2a2a2a;
  color: #aaa;
  border: 1px solid #3a3a3a;
  border-radius: 6px;
  font-size: 13px;
  cursor: pointer;
}

.verify-btn:hover {
  background: #333;
}

.footer {
  text-align: center;
  margin-top: 32px;
  font-size: 11px;
  color: #444;
}

.sample-section {
  margin-top: 16px;
  text-align: center;
}

.sample-btn {
  width: auto;
  display: inline-block;
  padding: 6px 14px;
  margin: 4px;
  background: transparent;
  color: #888;
  border: 1px solid #3a3a3a;
  border-radius: 16px;
  font-size: 12px;
  cursor: pointer;
}

.sample-btn:hover {
  background: #222;
  color: #ccc;
}

@media (max-width: 480px) {
  .header h1 {
    font-size: 24px;
  }
  textarea {
    min-height: 90px;
  }
  .container {
    padding: 0;
  }
}