## ADDED Requirements ### Requirement: Responsive layout baseline The site MUST be responsive across common breakpoints (mobile, tablet, desktop, and large desktop) and MUST not exhibit broken layouts (overlapping content, horizontal scrolling, clipped navigation). #### Scenario: Mobile viewport does not horizontally scroll - **WHEN** the site is viewed on a small mobile viewport - **THEN** content reflows to a single-column layout and the page does not require horizontal scrolling to read primary content #### Scenario: Large viewport uses available space without visual artifacts - **WHEN** the site is viewed on a large desktop viewport (ultrawide / high resolution) - **THEN** the background and layout scale without visible abrupt gradient cutoffs or banding artifacts ### Requirement: Collapsible primary navigation (hamburger menu) The primary navigation MUST collapse into a hamburger menu on smaller viewports. The menu toggle MUST be a `