* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
  font-family: Inter, Roboto, -apple-system, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  background: #f3f4f6;
  color: #111827;
}

header {
  padding: 16px 24px;
  background: #1f2937;
  color: #fff;
}

header h1 {
  margin: 0 0 4px;
  font-size: 1.6rem;
}

header p {
  margin: 0;
  opacity: 0.85;
  font-size: 0.95rem;
}

main {
  display: flex;
  height: calc(100vh - 88px);
}

#controls {
  width: 340px;
  padding: 16px;
  background: #f9fafb;
  border-right: 1px solid #e5e7eb;
  overflow-y: auto;
}

#controls section {
  margin-bottom: 18px;
}

#controls h2 {
  margin: 0 0 10px;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #4b5563;
}

label {
  display: block;
  margin-bottom: 6px;
  font-weight: 600;
  color: #374151;
}

select,
input[type="text"] {
  width: 100%;
  padding: 8px 10px;
  border-radius: 6px;
  border: 1px solid #d1d5db;
  margin-bottom: 12px;
  font-size: 0.95rem;
  background: #fff;
}

button {
  border: none;
  border-radius: 6px;
  padding: 8px 12px;
  background: #2563eb;
  color: #fff;
  cursor: pointer;
  font-size: 0.95rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

button:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

button:disabled {
  background: #9ca3af;
  cursor: not-allowed;
  box-shadow: none;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

#network {
  flex: 1;
  height: 100%;
  min-height: 400px;
}

#info {
  margin-top: 12px;
}

pre {
  background: #111827;
  color: #f8fafc;
  padding: 12px;
  border-radius: 8px;
  max-height: 200px;
  overflow-y: auto;
  font-size: 0.85rem;
}

input[type="file"] {
  width: 100%;
  margin-bottom: 10px;
}

.status-message {
  background: #dbeafe;
  color: #1d4ed8;
  border: 1px solid #bfdbfe;
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 0.85rem;
}

.status-message.error {
  background: #fee2e2;
  border-color: #fecaca;
  color: #b91c1c;
}

.status-subtle {
  font-size: 0.85rem;
  color: #4b5563;
}

.hint {
  font-size: 0.8rem;
  color: #6b7280;
  margin: 8px 0 0;
}

.error-panel {
  padding: 20px;
  background: #fee2e2;
  border: 1px solid #fecaca;
  color: #991b1b;
  border-radius: 8px;
  margin: 16px;
}

@media (max-width: 960px) {
  main {
    flex-direction: column;
  }
  #controls {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid #e5e7eb;
  }
  #network {
    height: 60vh;
  }
}