Scan: add small mobile size, fix chaininfo highlight

[evilpeach]

Implementation details

• Added media query for small mobile (>370px)
• Used it on ChainInfoHighLight.re

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[render]

Your Render PR Server URL is https://d3n-scan-pr-2347.onrender.com.

Follow its progress at https://dashboard.render.com/static/srv-bshp3p41do6neum8kse0.

[pzshine]

Cool!