:root{--background:#ffffff;--foreground:#000000;--accent:#000000}.theme-toggle{display:inline-block;padding:.4rem 1rem;border-radius:6px;background:var(--accent);color:var(--background);border:none;cursor:pointer;font-weight:600;line-height:1;box-shadow:0 1px 2px rgba(0,0,0,8%)}.theme-toggle:hover{opacity:.95}