Background of brand section is hidden in Firefox

[Lemon73-Computing]

Describe the bug
Background of brand section is hidden in Firefox.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'https://lemon73-computing.github.io/LEC-MainSite/'
2. Can't see background of brand section

Expected behavior
Can't see background of brand section

Screenshots
None

Desktop (please complete the following information):

• OS: KDE neon
• Browser: Firefox

Additional context
None