* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  background: #0f172a;
  color: #e2e8f0;
}

.app {
  max-width: 760px;
  margin: 24px auto;
  padding: 0 16px 24px;
}

h1 {
  margin-bottom: 4px;
}

.subtitle {
  margin-top: 0;
  color: #94a3b8;
}

.panel {
  background: #111827;
  border: 1px solid #1f2937;
  border-radius: 10px;
  padding: 14px;
  margin-top: 12px;
}

.drop-zone {
  display: block;
  border: 2px dashed #334155;
  border-radius: 8px;
  padding: 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color 120ms ease;
}

.drop-zone.drag-over {
  border-color: #22d3ee;
}

.file-meta {
  margin-bottom: 0;
  color: #93c5fd;
}

.controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}

.flash-option {
  flex-basis: 100%;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  margin: 4px 0 0;
  font-size: 0.9rem;
  color: #cbd5e1;
  cursor: pointer;
  user-select: none;
}

.flash-option input {
  margin-top: 3px;
  flex-shrink: 0;
}

button {
  border: 0;
  border-radius: 8px;
  padding: 10px 14px;
  font-weight: 600;
  cursor: pointer;
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#connect-btn {
  background: #06b6d4;
  color: #082f49;
}

#flash-btn {
  background: #22c55e;
  color: #052e16;
}

#disconnect-btn {
  background: #f59e0b;
  color: #451a03;
}

.status-panel .status-line {
  margin-bottom: 8px;
}

progress {
  width: 100%;
  height: 16px;
}

.log-output {
  min-height: 180px;
  max-height: 320px;
  overflow: auto;
  border-radius: 8px;
  border: 1px solid #1f2937;
  background: #020617;
  padding: 10px;
  margin: 0;
  white-space: pre-wrap;
}

.help ol {
  margin-bottom: 0;
}