🐛(site) Fix share overrides, small screen search, a2c langs

[Snugug]

Description

• Fixes share overrides for posts, making them ,well, work
• Fixes smalls screen search bar resulting in broken layout by swapping in an anchor link to actual search. Resolves Fix header search on small screens #763
• Fixes lang attributes missing in A2C generator. Resolves Add missing lang attribute to A2C legal attribution #764
• Fixes search page height not filling properly
• Fixes functions not working in variables (Sass)

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Other

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