Describe the bug

While auditing another site (which uses vitepress), I noticed the contrast ratio on code languages and line numbers doesn't meet WCAG guidelines.

Looking back to color system PR #2797 it seems as though --vp-c-text-3 was not intended to be used with --vp-c-bg-alt

XXX-3: The color for solid background, such as bg color of the button. It must satisfy the contrast ratio with pure white (#ffffff) text on top of it

I have a possible fix available and will submit a PR

System Info

System:
    OS: macOS 14.5
    CPU: (10) arm64 Apple M1 Max
    Memory: 5.63 GB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Browsers:
    Chrome: 131.0.6778.265
    Edge: 131.0.2903.112
    Safari: 17.5

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.