/** * Header Navigation * * VISUAL THEME FRAMEWORK. * * Styles the markup added to header.php in this phase: a logo/site * title, a horizontal nav menu (desktop), and a mobile menu toggle * button (hidden on desktop, shown below the medium breakpoint — * see mobile-menu.css for the menu panel itself). * * ISOLATION NOTE: header.php remains the one file responsible for * everything between and the first — this phase * adds markup INSIDE that boundary, never reaching into
or * referencing any section. The Structural Framework phase's * isolation contract (header never touches section content) is * unchanged. * * TOKEN-ONLY. */ .atb-header { position: sticky; top: 0; z-index: var(--atb-z-header, 100); background-color: var(--atb-color-background, #ffffff); border-bottom: 1px solid var(--atb-color-border, #e5e5e5); } .atb-header__inner { display: flex; align-items: center; justify-content: space-between; gap: var(--atb-space-6, 1.5rem); padding-top: var(--atb-space-4, 1rem); padding-bottom: var(--atb-space-4, 1rem); } .atb-header__logo { font-family: var(--atb-font-family-heading, sans-serif); font-weight: var(--atb-font-weight-bold, 700); font-size: var(--atb-font-size-xl, 1.25rem); color: var(--atb-color-text, #171717); text-decoration: none; letter-spacing: var(--atb-letter-spacing-tight, -0.02em); } .atb-header__logo:hover { color: var(--atb-color-text, #171717); } .atb-header__nav { display: flex; align-items: center; gap: var(--atb-space-8, 2rem); } .atb-header__nav-list { display: flex; align-items: center; gap: var(--atb-space-6, 1.5rem); margin: 0; padding: 0; list-style: none; } .atb-header__nav-link { font-family: var(--atb-font-family-base, sans-serif); font-size: var(--atb-font-size-sm, 0.875rem); font-weight: var(--atb-font-weight-medium, 500); color: var(--atb-color-text, #171717); text-decoration: none; } .atb-header__nav-link:hover { color: var(--atb-color-primary, #2563eb); } /* The mobile menu toggle button itself is styled here (it lives in the header markup); the panel it opens is styled separately in mobile-menu.css. Hidden on desktop by default. */ .atb-header__menu-toggle { display: none; align-items: center; justify-content: center; width: 2.5rem; height: 2.5rem; padding: 0; background: transparent; border: 1px solid var(--atb-color-border, #e5e5e5); border-radius: var(--atb-radius-md, 0.5rem); cursor: pointer; } .atb-header__menu-toggle-bar { display: block; width: 1.25rem; height: 2px; background-color: var(--atb-color-text, #171717); position: relative; } .atb-header__menu-toggle-bar::before, .atb-header__menu-toggle-bar::after { content: ""; position: absolute; left: 0; width: 100%; height: 2px; background-color: var(--atb-color-text, #171717); } .atb-header__menu-toggle-bar::before { top: -6px; } .atb-header__menu-toggle-bar::after { top: 6px; } /* Responsive: below the medium breakpoint, hide the desktop nav list and show the toggle button instead. KNOWN CSS LIMITATION: hardcoded to match --atb-breakpoint-md — see container.css. */ @media (max-width: 768px) { .atb-header__nav-list { display: none; } .atb-header__menu-toggle { display: flex; } }