You can import PDF files in the following ways:

• Click the "+" button in the app and select from device files
• Import through the "Share" function of other apps
• Import from cloud storage services (such as Google Drive)

In reading mode, click the annotation button in the top toolbar to use:

• Highlight: Select text and click the highlight button
• Text annotation: Double-click on blank space in the document to add annotations
• Brush tool: Free drawing and marking

Go to the settings menu and select "Cloud Sync":

• Connect your Google Drive or Dropbox account
• Select the folders to sync
• Enable automatic sync feature

First-time use requires setting a password:

• Enter a specific number sequence (like 123+) in the calculator interface
• Follow the prompts to set your access password
• Enter the password next time to access the private space

After entering the private space:

• Click the "+" button to select import files
• Select photos or videos to protect from the gallery
• Files will be encrypted and moved to the secure space

To ensure security, we provide the following recovery methods:

• Reset using set security questions
• Verify through fingerprint or face recognition
• Contact customer service for technical support