fixed button placement

src/App/App.css

src/components/Buttons.tsx

...nts/Human Practices/Further Engagement/Collaborations.tsx

...s/Human Practices/Further Engagement/Entrepreneurship.tsx

src/contents/Human Practices/Further Engagement/Outreach.tsx

src/contents/Human Practices/IHP.tsx

src/contents/Human Practices/Introduction.tsx

src/contents/interviews.tsx