Premium Shopify Theme Customization

I’m working with a premium Shopify theme and want it tailored to fit my brand’s look and flow.

Design updates I need:
• Refresh the homepage, product pages, and navigation menus so they feel cohesive and conversion-focused.
• Keep typography, color palette, and spacing consistent across every modified section.

Functionality to add:
• Advanced search filters that let shoppers narrow results by size, color, price, and other product attributes.
• A customer reviews section on product pages, styled to match the theme and easy for buyers to submit ratings.
• A streamlined, custom checkout process that reduces steps and supports discount codes.

The final store should be responsive, load quickly, and remain fully editable from Shopify’s theme editor. Please build using Liquid, HTML/CSS, and JavaScript best practices so future updates stay straightforward. I’m aiming for clean code, clear documentation, and a smooth hand-off once everything is tested and live.