* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: linear-gradient(135deg, #f5f7fa 0%, #e4edf5 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  color: #333;
}
.container {
  background: #fff;
  border-radius: 16px;
  padding: 32px;
  max-width: 500px;
  width: 100%;
  box-shadow: 0 10px 40px rgba(0,0,0,0.08);
}
h1 { margin-bottom: 8px; font-size: 24px; }
.container > p { color: #666; margin-bottom: 24px; }
form { display: flex; flex-direction: column; gap: 16px; }
textarea {
  width: 100%;
  padding: 12px;
  border: 2px solid #e0e6ed;
  border-radius: 8px;
  font-size: 16px;
  resize: vertical;
  transition: border-color 0.2s;
}
textarea:focus { outline: none; border-color: #0066ff; }
button {
  background: #0066ff;
  color: white;
  border: none;
  padding: 14px 24px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}
button:hover { background: #0052cc; }
button:disabled { background: #a0b4cc; cursor: not-allowed; }
.result {
  margin-top: 20px;
  padding: 12px;
  border-radius: 8px;
  font-size: 14px;
  display: none;
}
.result.success { background: #d4edda; color: #155724; display: block; }
.result.error { background: #f8d7da; color: #721c24; display: block; }
.info {
  margin-top: 24px;
  padding: 16px;
  background: #f8f9fa;
  border-radius: 8px;
  font-size: 13px;
}
.info summary { cursor: pointer; font-weight: 600; margin-bottom: 12px; }
.info label {
  display: block;
  margin: 10px 0;
}
.info input {
  width: 100%;
  padding: 8px;
  margin-top: 4px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 13px;
}