* {
  box-sizing: border-box;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  margin: 0;
  padding: 0;
  background: #f4f6f8;
  color: #0f172a;
}

header,
footer {
  background: #0f172a;
  color: #f8fafc;
  padding: 1.5rem;
  text-align: center;
}

main {
  max-width: 960px;
  margin: 2rem auto;
  display: grid;
  gap: 1.5rem;
}

.panel {
  background: #ffffff;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.08);
}

.panel.error {
  border-left: 6px solid #ef4444;
}

.warning {
  background: #fef3c7;
  color: #92400e;
  border-left: 4px solid #f59e0b;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  margin-bottom: 1rem;
  white-space: pre-wrap;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

textarea,
input,
button {
  width: 100%;
  padding: 0.75rem;
  border-radius: 8px;
  border: 1px solid #cbd5f5;
  font-size: 1rem;
  margin-bottom: 1rem;
}

textarea:focus,
input:focus {
  outline: none;
  border-color: #2563eb;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

.options {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.options label {
  margin-bottom: 0;
  font-weight: 500;
}

button {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: #fff;
  border: none;
  cursor: pointer;
  font-weight: 600;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

button:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 20px rgba(37, 99, 235, 0.25);
}

button.secondary {
  background: linear-gradient(135deg, #64748b, #475569);
}

pre {
  background: #0f172a;
  color: #e2e8f0;
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
}

th,
td {
  border: 1px solid #e2e8f0;
  padding: 0.65rem;
  text-align: left;
}

th {
  background: #f1f5f9;
}

#error-message {
  white-space: pre-wrap;
}

#feedback-panel {
  margin-top: 1.5rem;
}

.feedback-actions {
  display: flex;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

#feedback-status {
  color: #0369a1;
  font-weight: 600;
}