:root{--fondo: #0f172a;--superficie: #1e293b;--borde: #334155;--texto: #e2e8f0;--tenue: #94a3b8;--acento: #38bdf8}*{box-sizing:border-box}body{margin:0;background:var(--fondo);color:var(--texto);font-family:system-ui,-apple-system,Segoe UI,sans-serif;line-height:1.6}main{max-width:560px;margin:0 auto;padding:64px 16px;text-align:center}h1{margin:0 0 4px;font-size:2rem;letter-spacing:-.02em}.subtitulo{margin:0 0 40px;color:var(--tenue)}.tarjeta{background:var(--superficie);border:1px solid var(--borde);border-radius:12px;padding:32px 24px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap}button{padding:12px 24px;font-size:1rem;font-family:inherit;color:#0f172a;background:var(--acento);border:none;border-radius:8px;cursor:pointer}button:hover{filter:brightness(1.1)}button:focus-visible{outline:2px solid var(--texto);outline-offset:2px}.secundario{background:transparent;color:var(--tenue);border:1px solid var(--borde)}footer{margin-top:40px;color:var(--tenue);font-size:.85rem}code{font-family:ui-monospace,Menlo,monospace;color:var(--acento);background:var(--superficie);padding:2px 6px;border-radius:4px}