Website: Fixed anchortags

[CronKz]

• Fixed visibilty of anchors by removing display: none and adding overflow: visible

Additional fixes

• Fixed anchor color variable (defaulted to black before)

- fill="var(--heading-text-color)"
+ fill="var(--cc-heading-text-color)"

• Added scroll margins considering "sticky" headers to prevent overlapping
• Adjusted the responsive article menu position. It was not blurring the edges. (Visible if a full-width "warning" box was below)

Closes #7908

[rstaib]

@CronKz First of all thanks for your contribution. I will go through it and test it probably today.

[CronKz]

@rstaib Thanks, take any time you need. Let me know if there is anything I can help you with.