The nav previously showed 4 inline flag buttons (DE/EN/UK/RU) on desktop
and a details-based dropdown on mobile. Martin asked for one dropdown with
a trigger the size of a single flag, and the 4 inline flags to go away.
- LocaleSwitcher: render a single <details class='locale-switcher'>
everywhere; trigger is one flag + tiny caret; menu lists all 4 with labels.
- Drop the 4-inline <ul> and the locale-switcher-mobile duplicate.
- CSS: replace both blocks with one compact dropdown (flag-sized trigger,
44px touch target via padding, scrolled/transparent-nav variants).
- Tests: assert 4 menu options, 5 flag SVGs, single <details> dropdown,
active locale is a <span aria-current>, others are <a> with hreflang.
- 141/141 PHPUnit green.
- mobile (≤900px): hide .nav-cta (was overflowing viewport by 65px)
- .nav-hamburger span: center inside button via left:50%; top:50%
- .nav-hamburger.active states: add translate(-50%,-50%) so the X
lines stay centered after rotation
- .hero-bg: switch from background-* to object-fit/object-position
(was an <img> but CSS targeted background-image → 1024px wide
hero-bg broke mobile layout)
- responsive: also override nav.scrolled padding on mobile
(specificity 0,1,1 > 0,0,1 → 3rem padding stayed in effect,
pushing the hamburger off-screen with width:0 on scroll)
- home/index.php: rename lage-map → lage-map-wrapper so the
existing .lage-map-wrapper CSS (border, margin-top: 3rem,
overflow: hidden, full-width 450px iframe) actually applies
