body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f4f4f4;
  color: #333;
}

header {
  background: #6200ea;
  color: white;
  padding: 10px;
  display: flex;
  justify-content: space-between;
}

#upload-section {
  border: 2px dashed #6200ea;
  padding: 20px;
  margin: 10px;
  text-align: center;
  background: white;
}

#pdf-preview {
  text-align: center;
}

canvas {
  max-width: 90%;
  border: 1px solid #ccc;
  margin-top: 10px;
}

#pdf-controls {
  margin-top: 10px;
}

#chat-section {
  margin: 10px;
  background: white;
  padding: 10px;
  border-radius: 6px;
}

#chat-history {
  max-height: 250px;
  overflow-y: auto;
  margin-bottom: 10px;
  border: 1px solid #ccc;
  padding: 5px;
}

#input-section {
  display: flex;
  gap: 5px;
}

.dark-mode {
  background: #121212;
  color: white;
}

.dark-mode header {
  background: #333;
}

.dark-mode #upload-section {
  background: #222;
  border-color: #888;
}