When browser width is between 840px and 770px a horizontal scrollbar appears when there are too many items #2842

Describe the bug

When browser width is between 840px and 770px, a horizontal scrollbar appears when there are too many items.

Reproduction

• Add 10 items or more to your nav in themeConfig.
• Resize your browser to any width between 840px and 770px.
• Observe the horizontal scrollbar.

Expected behavior

Sidebar items should overflow in an overflow menu.

System Info

Binaries:
    Node: 19.6.1 - J:\nodejs\node.EXE
    npm: 9.4.0 - J:\nodejs\npm.CMD
    pnpm: 8.6.12 - C:\users\(redacted for PII)\Downloads\pnpm.EXE
Browsers:
    Edge: Spartan (44.22621.2199.0), Chromium (116.0.1938.54), ChromiumDev (117.0.2045.1)
    Internet Explorer: 11.0.22621.1

Additional context

Validations

• Check if you're on the latest VitePress version.
• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.