/* Portada (entrada de pantallas con la clave del espacio). */
    :root{--bg:#070b15;--text:#f6f8ff;--muted:rgba(255,255,255,.72);--stroke:rgba(255,255,255,.12);--accent:#aab8ff}
    *{box-sizing:border-box}html,body{height:100%;margin:0}
    body{display:grid;place-items:center;background:radial-gradient(900px 650px at 80% 10%, rgba(141,162,255,.14), transparent 60%),radial-gradient(880px 640px at 10% 90%, rgba(15,161,186,.10), transparent 60%),var(--bg);color:var(--text);font-family:Inter,system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;padding:22px}
    main{width:min(620px,100%);display:grid;gap:18px;text-align:center}
    h1{margin:0;font-size:clamp(36px,6vw,58px);line-height:1.02;font-weight:800}
    p{margin:0;color:var(--muted);font-size:18px;line-height:1.6}
    .btn{appearance:none;border:1px solid rgba(255,255,255,.16);background:rgba(255,255,255,.05);color:#fff;border-radius:999px;padding:16px 24px;font-weight:800;font-size:16px;cursor:pointer}
    .btn:disabled{opacity:.5;cursor:not-allowed}
    .panel{display:none;gap:12px;justify-items:center}
    .panel.show{display:grid}
    input{width:min(420px,100%);padding:14px 16px;border-radius:16px;border:1px solid var(--stroke);background:rgba(255,255,255,.05);color:#fff;font-size:16px;outline:none}
    .helper{min-height:22px;color:var(--muted);font-size:14px}
    .helper.error{color:#ffb4b4}.helper.ok{color:#93efbf}
.centrado{justify-self:center}