Fix missing upload button

[omar-ahmed42]

Description

The code snippet input[type=file]{ display: none;} was unintentionally hiding the upload button everywhere, to fix this, it was changed to only target input within .input-container.

Closes #2390

Checklist

• I have read the Contribution Guidelines
• I have performed a self-review of my own code
• I have attached images of the change if it is UI based
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