Code zone(generated by indent of markdown grammer) is invisible in frontend

[hw712]

Bug report

Version

• VuePress 0.10.2

Steps to reproduce

Write markdown with indent style code zone, the generated code zone is <pre><code> without any class specified. The background is transparent and text color is white, which makes it invisible in the frontend.

## Here below is the sample of code zone
Some sentence here...
    //some code here
    print("hello world!")

What is expected?

The code area should have a dark background color.

What is actually happening?

The code area's background color is white.

Other relevant information

• Your OS: Windows 7
• Node.js version: 8.11.3
• Browser version: Firefox 60
• Is this a global or local install? Global
• Which package manager did you use for the install? npm 6.1.0

[ulivz]

Thanks, fixed at fd46a26.