body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #0f172a;
  color: #e2e8f0;
}

.container {
  max-width: 700px;
  margin: 60px auto;
  padding: 24px;
  background: #1e293b;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

h1 {
  text-align: center;
  margin-bottom: 8px;
}

.subtitle {
  text-align: center;
  color: #94a3b8;
  margin-bottom: 16px;
  font-size: 14px;
}

textarea {
  width: 100%;
  height: 120px;
  padding: 10px;
  border-radius: 8px;
  border: 1px solid #334155;
  background: #0f172a;
  color: #f1f5f9;        
  margin-bottom: 15px;
  font-size: 14px;
  resize: vertical;
  outline: none;
}

textarea:focus {
  border-color: #38bdf8;
}

button {
  width: 100%;
  padding: 10px;
  background: #38bdf8;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
  color: #000;
  font-weight: 600;
}

button:hover {
  background: #0ea5e9;
}

.error {
  color: #f87171;
  margin-top: 10px;
  font-size: 13px;
  min-height: 20px;
}

h3 {
  margin-top: 20px;
  margin-bottom: 8px;
  color: #94a3b8;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

pre {
  background: #020617;
  color: #4ade80;          
  padding: 14px;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.6;
  min-height: 48px;
  border: 1px solid #1e3a2f;
}