Mobile-optimized Menu Items

**Context**

> Is your feature request related to a problem? What is the motivation for implementing this feature?

Currently, clicking search in mobile (and on desktop) pulls open a drawer that takes up 25 to 75% of the book's real estate -- even before a search is conducted.

Proposing options (instead of being vertical) become horizontal on mobile, more like:

And that when **search** in particular is enabled, results are only shown **after** a search is performed.

e.g.

**Proposal & Constraints**

> What is the proposed solution / implementation? Is there a precedent for this approach succeeding elsewhere?

> Which suggestions or requirements should be considered for how this feature needs to appear or be implemented?

**Additional Resources**

> Add any other screenshots or assets related to the feature request.

**Success Metrics**

> How will you know if this change is successful? What specific metrics are relevant and how do you expect them to change?

**Stakeholders**

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