The background is not displayed on safari v14

[syJSdev]

Describe the bug
The background is not displayed when the selector is null on safari v14.

To Reproduce

[
  {
    "selector": null,
    "step": 1,
    "title": "Tour",
    "content": "Example tour description."
  }
]

Screenshots

• Current
  
• Expected
  

Desktop (please complete the following information):

• OS: macOS v11 Big Sur
• Browser: Safari 14.0.2
• Version: 0.2.1