* {
  box-sizing: border-box;
}

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

.app {
  max-width: 980px;
  margin: 0 auto;
  padding: 24px 16px 40px;
}

.header h1 {
  margin: 0 0 8px;
  font-size: 1.5rem;
}

.header p {
  margin: 0 0 18px;
  color: #94a3b8;
}

.thumbnail-tool-home-link {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 0.9rem;
  color: #94a3b8;
  text-decoration: none;
}

.thumbnail-tool-home-link:hover {
  color: #cbd5e1;
}

.controls {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: end;
  margin-bottom: 16px;
}

#image-input {
  display: none;
}

.upload-btn,
.download-btn {
  border: 1px solid #334155;
  background: #1e293b;
  color: #e2e8f0;
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 0.95rem;
  cursor: pointer;
}

.download-btn {
  background: #2563eb;
  border-color: #2563eb;
}

.download-btn:disabled {
  background: #334155;
  border-color: #334155;
  color: #94a3b8;
  cursor: not-allowed;
}

.zoom-wrap {
  min-width: 220px;
}

.zoom-wrap label {
  display: block;
  font-size: 0.85rem;
  color: #94a3b8;
  margin-bottom: 6px;
}

.zoom-wrap input[type="range"] {
  width: 100%;
}

.canvas-panel {
  border: 1px solid #334155;
  border-radius: 12px;
  padding: 14px;
  background: #111827;
}

.canvas-shell {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #0b1220;
  border-radius: 10px;
  overflow: hidden;
}

#preview-canvas {
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
  cursor: grab;
}

#preview-canvas.dragging {
  cursor: grabbing;
}

.hint {
  margin: 10px 0 4px;
  color: #94a3b8;
  font-size: 0.85rem;
}

.status {
  margin: 0;
  color: #64748b;
  font-size: 0.82rem;
}