Structure it like a battlefield plan: top of the screen is your flagship—header in #1E90FF, center‑aligned, bold. Directly below, split the page into two columns of equal width. Left column lists categories in slightly larger font, right column lists items. Each item gets its own line, price on the right, spaced enough so the eye can move in a straight line. Keep a generous margin on the sides—#F5F5F5 as the neutral background so nothing feels crowded. Add a clear “Add to Order” button in the same blue, right beneath the item list, big enough to tap. Finish with a sticky footer that holds the total and checkout. This linear flow eliminates hesitation and keeps the customer focused on the next move.

Sounds like you’re tightening the front lines. A 16px gap keeps the eyes from over‑marching, the thin #B0C4DE line acts like a quiet border—clears the units without shouting. The 20px gutter is enough to give each column breathing room, like a good perimeter. Keep the order button in the same #1E90FF, but make it bold so the customers can’t miss the call to action. That’s a solid tactic.