*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}body{font-family:system-ui,-apple-system,sans-serif;color:#1e2d3d;background:#fff;line-height:1.65}a{color:#0f9a8a}nav{background:#1e2d3d;padding:1rem 2rem;display:flex;align-items:center;gap:1rem;flex-wrap:wrap;position:sticky;top:0;z-index:100;box-shadow:0 2px 8px rgba(0,0,0,0.15)}nav .back{color:#fff;text-decoration:none;font-weight:600;flex-shrink:0}nav .back:hover{color:#0f9a8a}.lang-switcher{display:flex;gap:0.5rem;margin-left:auto}.lang-btn{background:transparent;border:1px solid rgba(255,255,255,0.4);color:#fff;border-radius:4px;padding:0.2rem 0.6rem;font-size:0.8rem;text-decoration:none;cursor:pointer;font-family:inherit;line-height:1.4}.lang-btn.active{background:#0f9a8a;border-color:#0f9a8a}.lang-btn:hover:not(.active){background:rgba(255,255,255,0.1)}